unethical treatments - Science-Education-Research

Educational experiments – making the best of an unsuitable tool?

Can small-scale experimental investigations of teaching carried-out in a couple of arbitrary classrooms really tells us anything about how to teach well?

Keith S. Taber

Undertaking valid educational experiments involves (often, insurmountable) challenges, but perhaps this grid (shown larger below) might be useful for researchers who do want to do genuinely informative experimental studies into teaching?

Applying experimental method to educational questions is a bit like trying to use a precision jeweller's screwdriver to open a tin of paint: you may get the tin open eventually, but you will probably have deformed the tool in the process whilst making something of a mess of the job.

In recent years I seem to have developed something of a religious fervour about educational research studies of the kind that claim to be experimental evaluations of pedagogies, classroom practices, teaching resources, and the like. I think this all started when, having previously largely undertaken interpretive studies (for example, interviewing learners to find out what they knew and understood about science topics) I became part of a team looking to develop, and experimentally evaluate, classroom pedagogy (i.e., the epiSTEMe project).

As a former school science teacher, I had taught learners about the basis of experimental method (e.g., control of variables) and I had read quite a number of educational research studies based on 'experiments', so I was pretty familiar with the challenges of doing experiments in education. But being part of a project which looked to actually carry out such a study made a real impact on me in this regard. Well, that should not be surprising: there is a difference between watching the European Cup Final on the TV, and actually playing in the match, just as reading a review of a concert in the music press is not going to impact you as much as being on stage performing.

Let me be quite clear: the experimental method is of supreme value in the natural sciences; and, even if not all natural science proceeds that way, it deserves to be an important focus of the science curriculum. Even in science, the experimental strategy has its limitations. ¹ But experiment is without doubt a precious and powerful tool in physics and chemistry that has helped us learn a great deal about the natural world. (In biology, too, but even here there are additional complications due to the variations within populations of individuals of a single 'kind'.)

But transferring experimental method from the laboratory to the classroom to test hypotheses about teaching is far from straightforward. Most of the published experimental studies drawing conclusions about matters such as effective pedagogy, need to be read with substantive and sometimes extensive provisos and caveats; and many of them are simply invalid – they are bad experiments (Taber, 2019). ²

The experiment is a tool that has been designed, and refined, to help us answer questions when:

we are dealing with non-sentient entities that are indifferent to outcomes;
we are investigating samples or specimens of natural kinds;
we can identify all the relevant variables;
we can measure the variables of interest;
we can control all other variables which could have an effect;

These points simply do not usually apply to classrooms and other learning contexts. ³ (This is clearly so, even if educational researchers often either do not appreciate these differences, or simply pretend they can ignore them.)

Applying experimental method to educational questions is a bit like trying to use a precision jeweller's screwdriver to open a tin of paint: you may get the tin open eventually, but you will probably have deformed the tool in the process whilst making something of a mess of the job.

The reason why experiments are to be preferred to interpretive ('qualitative') studies is that supposedly experiments can lead to definite conclusions (by testing hypotheses), whereas studies that rely on the interpretation of data (such as classroom observations, interviews, analysis of classroom talk, etc.) are at best suggestive. This would be a fair point when an experimental study genuinely met the control-of-variables requirements for being a true experiment – although often, even then, to draw generalisable conclusions that apply to a wide population one has to be confident one is working with a random or representatives sample, and use inferential statistics which can only offer a probabilistic conclusion.

My creed…researchers should prefer to undertake competent work

My proselytising about this issue, is based on having come to think that:

most educational experiments do not fully control relevant variables, so are invalid;
educational experiments are usually subject to expectancy effects that can influence outcomes;
many (perhaps most) educational experiments have too few independent units of analysis to allow the valid use of inferential statistics;
most large-scale educational experiments can not assure that samples are fully representative of populations, so strictly cannot be generalised;
many experiments are rhetorical studies that deliberately compare a condition (supposedly being tested but actually) assumed to be effective with a teaching condition known to fall short of good teaching practice;
an invalid experiment tells us nothing that we can rely upon;
a detailed case study of a learning context which offers rich description of teaching and learning potentially offers useful insights;
given a choice between undertaking a competent study of a kind that can offer useful insights, and undertaking a bad experiment which cannot provide valid conclusions, researchers should prefer to undertake competent work;
what makes work scientific is not the choice of methodology per se, but the adoption of a design that fits the research constraints and offers a genuine opportunity for useful learning.

However, experiments seem very popular in education, and often seem to be the methodology of choice for researchers into pedagogy in science education.

Read: Why do natural scientists tend to make poor social scientists?

This fondness of experiments will no doubt continue, so here are some thoughts on how to best draw useful implications from them.

A guide to using experiments to inform education

It seems there are two very important dimensions that can be used to characterise experimental research into teaching – relating to the scale and focus of the research.

Two dimensions used to characterise experimental studies of teaching

Scale of studies

A large-scale study has a large number 'units of analysis'. So, for example, if the research was testing out the value of using, say, augmented reality in teaching about predator-prey relationships, then in such a study there would need to be a large number of teaching-learning 'units' in the augmented learning condition and a similarly large number of teaching-learning 'units' in the comparison condition. What a unit actually is would vary from study to study. Here a unit might be a sequence of three lessons where a teacher teaches the topic to a class of 15-16 year-old learners (either with, or without, the use of augmented reality).

For units of analysis to be analysed statistically they need to be independent from each other – so different students learning together from the same teacher in the same classroom at the same time are clearly not learning independently of each other. (This seems obvious – but in many published studies this inconvenient fact is ignored as it is 'unhelpful' if researchers wish to use inferential statistics but are only working with a small number of classes. ⁴)

Read about units of analysis in research

So, a study which compared teaching and learning in two intact classes can usually only be considered to have one unit of analysis in each condition (making statistical tests completely irrelevant ⁵, thought this does not stop them often being applied anyway). There are a great many small scale studies in the literature where there are only one or a few units in each condition.

Focus of study

The other dimension shown in the figure concerns the focus of a study. By the focus, I mean whether the researchers are interested in teaching and learning in some specific local context, or want to find out about some general population.

Read about what is meant by population in research

Studies may be carried out in a very specific context (e.g., one school; one university programme) or across a wide range of contexts. That seems to simply relate to the scale of the study, just discussed. But by focus I mean whether the research question of interest concerns just a particular teaching and learning context (which may be quite appropriate when practitioner-researchers explore their own professional contexts, for exmample), or is meant to help us learn about a more general situation.

local focus	general focus
Why does *school X* get such outstanding science examination scores?	Is there a relationship between teaching pedagogy employed and science examination results *in English schools*?
Will jig-saw learning be a productive way to teach *my A level class* about the properties of the transition elements?	Is jig-saw learning an effective pedagogy for use in A level chemistry classes?

Some hypothetical research questions relating either to a specific teaching context, or a wider population. (n.b. The research literature includes a great many studies that claim to explore general research questions by collecting data in a single specific context.)

If that seems a subtle distinction between two quite similar dimensions then it is worth noting that the research literature contains a great many studies that take place in one context (small-scale studies) but which claim (implicitly or explicitly) to be of general relevance. So, many authors, peer reviewers, and editors clearly seem think one can generalise from such small scale studies.

Generalisation

Generalisation is the ability to draw general conclusions from specific instances. Natural science does this all the time. If this sample of table salt has the formula NaCl, then all samples of table salt do; if the resistance of this copper wire goes up when the wire is heated the same will be found with other specimens as well. This usually works well when dealing with things we think are 'natural kinds' – that is where all the examples (all samples of NaCl, all pure copper wires) have the same essence.

Read about generalisation in research

Education deals with teachers, classes, lessons, schools…social kinds that lack that kind of equivalence across examples. You can swap any two electrons in a structure and it will make absolutely no difference. Does any one think you can swap the teachers between two classes and safely assume it will not have an effect?

So, by focus I mean whether the point of the research is to find out about the research context in its own right (context-directed research) or to learn something that applies to a general category of phenomena (theory-directed research).

These two dimensions, then, lead to a model with four quadrants.

Large-scale research to learn about the general case

In the top-right quadrant is research which focuses on the general situation and is larger-scale. In principle ⁶ this type of research can address a question such as 'is this pedagogy (teaching resource, etc.) generally effective in this population', as long as

the samples are representative of the wider population of interest, and
those sampled are randomly assigned to conditions, and
the number of units supports statistical analysis.

The slight of hand employed in many studies is to select a convenience sample (two classes of thirteen years old students at my local school) yet to claim the research is about, and so offers conclusions about, a wider population (thirteen year learners).

Read about some examples of samples used to investigate populations

When an experiment tests a sample drawn at random from a wider population, then the findings of the experiment can be assumed to (probably) apply (**on average**) to the population. (Taber, 2019)

Even when a population is properly sampled, it is important not to assume that something which has been found to be generally effective in a population will be effective throughout the population. Schools, classes, courses, learners, topics, etc. vary. If it has been found that, say, teaching the reactivity series through enquiry generally works in the population of English classes of 13-14 year students, then a teacher of an English class of 13-14 year students might sensibly think this is an approach to adopt, but cannot assume it will be effective in her classroom, with a particular group of students.

To implement something that has been shown to generally work might be considered research-based teaching, as long as the approach is dropped or modified if indications are it is not proving effective in this particular context. That is, there is nothing (please note, UK Department for Education, and Ofsted) 'research-based' about continuing with a recommended approach in the face of direct empirical evidence that it is not working in your classroom.

Large-scale research to learn about the range of effectiveness

However, even large-scale studies where there are genuinely sufficient units of analysis for statistical analysis may not logically support the kinds of generalisation in the top-right quadrant. For that, researchers needs either a random sampling of the full population (seldom viable given people and institutions must have a choice to participate or not ⁷), or a sample which is known to be representative of the population in terms of the relevant characteristics – which means knowing a lot about

(i) the population,
(ii) the sample, and
(ii) which variables might be relevant!

Imagine you wanted to undertake a survey of physics teachers in some national context, and you knew you could not reach all that population so you needed to survey a sample. How could you possibly know that the teachers in your sample were representative of the wider population on whatever variables might potentially be pertinent to the survey (level of qualification?; years of experience?; degree subject?; type of school/college taught in?; gender?…)

But perhaps a large scale study that attracts a diverse enough sample may still be very useful if it collects sufficient data about the individual units of analysis, and so can begin to look at patterns in how specific local conditions relate to teaching effectiveness. That is, even if the sample cannot be considered representative enough for statistical generalisation to the population, such a study might be a be to offer some insights into whether an approach seems to work well in mixed-ability classes, or top sets, or girls' schools, or in areas of high social deprivation, or…

In practice, there are very few experimental research studies which are large-scale, in the sense of having enough different teachers/classes as units of analysis to sit in either of these quadrants of the chart. Educational research is rarely funded at a level that makes this possible. Most researchers are constrained by the available resources to only work with a small number of accessible classes or schools.

So, what use are such studies for producing generalisable results?

Small-scale research to incrementally extend the range of effectiveness

A single small-scale study can contribute to a research programme to explore the range of application of an innovation as if it was part of a large-scale study with a diverse sample. But this means such studies need to be explicitly conceptualised and planned as part of such a programme.

At the moment it is common for research papers to say something like

"…lots of research studies, from all over the place, report that asking students to

(i) first copy science texts omitting all the vowels, and then

(ii) re-constituting them in full by working from the reduced text, by writing it out adding vowels that produce viable words and sentences,

is an effective way of supporting the learning of science concepts; but no one has yet reported testing this pedagogic method when twelve year old students are studying the topic of acids in South Cambridgeshire in a teaching laboratory with moveable stools and West-facing windows.

In this ground-breaking study, we report an experiment to see if this constructivist, active-learning, teaching approach leads to greater science learning among twelve year old students studying the topic of acids in South Cambridgeshire in a teaching laboratory with moveable stools and West-facing windows…"

Over time, the research literature becomes populated with studies of enquiry-based science education, jig-saw learning, use of virtual reality, etc., etc., and these tend to refer to a range of national contexts, variously aged students, diverse science topics, etc., this all tends to be piecemeal. A coordinated programme of research could lead to researchers both (a) giving rich description of the context used, and (b) selecting contexts strategically to build up a picture across ranges of contexts,

"When there is a series of studies testing the same innovation, it is most useful if collectively they sample in a way that offers maximum information about the potential range of effectiveness of the innovation.There are clearly many factors that may be relevant. It may be useful for replication studies of effective innovations to take place with groups of different socio-economic status, or in different countries with different curriculum contexts, or indeed in countries with different cultural norms (and perhaps very different class sizes; different access to laboratory facilities) and languages of instruction …. It may be useful to test the range of effectiveness of some innovations in terms of the ages of students, or across a range of quite different science topics. Such decisions should be based on theoretical considerations.

Given the large number of potentially relevant variables, there will be a great many combinations of possible sets of replication conditions. A large number of replications giving similar results within a small region of this 'phase space' means each new study adds little to the field. If all existing studies report positive outcomes, then it is most useful to select new samples that are as different as possible from those already tested. …

When existing studies suggest the innovation is effective in some contexts but not others, then the characteristics of samples/context of published studies can be used to guide the selection of new samples/contexts (perhaps those judged as offering intermediate cases) that can help illuminate the boundaries of the range of effectiveness of the innovation."
Taber, 2019

Not that the research programme would be co-ordinated by a central agency or authority, but by each contributing researcher/research team (i) taking into account the 'state of play' at the start of their research; (ii) making strategic decisions accordingly when selecting contexts for their own work; (iii) reporting the context in enough detail to allow later researchers to see how that study fits into the ongoing programme.

This has to be a more scientific approach than simply picking a convenient context where researchers expect something to work well; undertake a small-scale local experiment (perhaps setting up a substandard control condition to be sure of a positive outcome); and then report along the lines "this widely demonstrated effective pedagogy works here too", or, if it does not, perhaps putting the study aside without publication. As the philosopher of science, Karl Popper, reminded us, science proceeds through the testing of bold conjectures: an 'experiment' where you already know the outcome is actually a demonstration. Demonstrations are useful in teaching, but do not contribute to research. What can contribute is an experiment in a context where there is reason to be unsure if an innovation will be an improvement or not, and where the comparison reflects good teaching practice to offer a meaningful test.

Small-scale research to inform local practice

Now, I would be the first to admit that I am not optimistic that such an approach will be developed by researchers; and even if it is, it will take time for useful patterns to arise that offer genuine insights into the range of convenience of different pedagogies.

Does this mean that small-scale studies in single context are really a waste of research resource and an unmerited inconvenient for those working in such contexts?

Well, I have time for studies in my final (bottom left) quadrant. Given that schools and classrooms and teachers and classes all vary considerably, and that what works well in a highly selective boys-only fee-paying school with a class size of 16 may not be as effective in a co-educational class of 32 mixed ability students in an under-resourced school in an area of social deprivation – and vice versa, of course!, there is often value in testing out ideas (even recommended 'research-based' ones) in specific contexts to inform practice in that context. These are likely to be genuine experiments, as the investigators are really motived to find out what can improve practice in that context.

Often such experiments will not get published,

perhaps because the researchers are teachers with higher priorities than writing for publication;
perhaps because it is assumed such local studies are not generalisable (but they could sometimes be moved into the previous category if suitably conceptualised and reported);
perhaps because the investigators have not sought permissions for publication (part of the ethics of research), usually not necessary for teachers seeking innovations to improve practice as part of their professional work;
perhaps because it has been decided inappropriate to set up control conditions which are not expected to be of benefit to those being asked to participate;
but also because when trying out something new in a classroom, one needs to be open to make ad hoc modifications to, or even abandon, an innovation if it seems to be having a deleterious effect.

Evaluation of effectiveness here usually comes down to professional judgement (rather than statistical testing – which assumes a large random sample of a population – being used to invalidly generalise small, non-random, local results to that population) which might, in part, rely on the researcher's close (and partially tacit) familiarity with the research context.

I am here describing 'action research', which is highly useful for informing local practice, but which is not ideally suited for formal reporting in academic journals.

Read about action research

So, I suspect there may be an irony here.

There may be a great many small-scale experiments undertaken in schools and colleges which inform good teaching practice in their contexts, without ever being widely reported; whilst there are a great many similar scale, often 'forced' experiments, carried out by visiting researchers with little personal stake in the research context, reporting the general effectiveness of teaching approaches, based on misuse of statistics. I wonder which approach best reflects the true spirit of science?

Source cited:

Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058 [Download article]

Notes:

¹ For example:

Even in the natural sciences, we can never be absolutely sure that we have controlled all relevant variables (after all, if we already knew for sure which variables were relevant, we would not need to do the research). But usually existing theory gives us a pretty good idea what we need to control.

Experiments are never a simple test of the specified hypothesis, as the experiment is likely to depends upon the theory of instrumentation and the quality of instruments. Consider an extreme case such as the discovery of the Higgs boson at CERN: the conclusions relied on complex theory that informed the design of the apparatus, and very challenging precision engineering, as well as complex mathematical models for interpreting data, and corresponding computer software specifically programmed to carry out that analysis.

The experimental results are a test of a hypothesis (e.g., that a certain particle would be found at events below some calculated energy level) subject to the provisos that

the theory of the the instrument and its design is correct; and
the materials of the apparatus (an apparatus as complex and extensive as a small city) have no serious flaws; and
the construction of the instrumentation precisely matches the specifications;
and the modelling of how the detectors will function (including their decay in performance over time) is accurate; and
the analytical techniques designed to interpret the signals are valid;
the programming of the computers carries out the analysis as intended.

It almost requires an act of faith to have confidence in all this (and I am confident there is no one scientist anywhere in the world who has a good enough understanding and familiarity will all these aspects of the experiment to be able to give assurances on all these areas!)

CREST {Critical Reading of Empirical Studies} evaluation form: when you read a research study, do you consider the cumulative effects of doubts you may have about different aspects of the work?

I would hope at least that as professional scientists and engineers they might be a little more aware of this complex chain of argumentation needed to support robust conclusions than many students – for students often seem to be overconfident in the overall value of research conclusions given any doubts they may have about aspects of the work reported.

Read about the Critical Reading of Empirical Studies Tool

Galileo Galilei was one of the first people to apply the telescope to study the night sky (image by Dorothe from Pixabay)

A historical example is Galileo's observations of astronomical phenomena such as Jovian moons (he spotted the four largest: Io, Europa, Ganymede and Callisto) and the irregular surface of the moon. Some of his contemporaries rejected these findings on the basis that they were made using an apparatus, the newly fanged telescope, that they did not trust. Whilst this is now widely seen as being arrogant and/or ignorant, arguably if you did not understand how a telescope could magnify, and you did not trust the quality of the lenses not to produce distortions, then it was quite reasonable to be sceptical of findings which were counter to a theory of the 'heavens' that had been generally accepted for many centuries.

² I have discussed a number of examples on this site. For example:

Falsifying research conclusions: You do not need to falsify your results if you are happy to draw conclusions contrary to the outcome of your data analysis.

Why ask teachers to 'transmit' knowledge…if you believe that "knowledge is constructed in the minds of students"?

Shock result: more study time leads to higher test scores (But 'all other things' are seldom equal)

Experimental pot calls the research kettle black: Do not enquire as I do, enquire as I tell you

Lack of control in educational research: Getting that sinking feeling on reading published studies

³ For a detailed discussion of these and other challenges of doing educational experiments, see Taber, 2019.

⁴ Consider these two situations.

A researcher wants to find out if a new textbook 'Science for the modern age' leads to more learning among the Grade 10 students she teaches than the traditional book 'Principles of the natural world'. Imagine there are fifty grade 10 students divided already into two classes. The teacher flips a coin and randomly assigns one of the classes to the innovative book, the other being assigned by default the traditional book. We will assume she has a suitable test to assess each students' learning at the end of the experiment.

The teacher teaches the two classes the same curriculum by the same scheme of work. She presents a mini-lecture to a class, then sets them some questions to discuss using the text book. At the end of the (three part!) lesson, she leads a class disucsison drawing on students' suggested answers.

Being a science teacher, who believes in replication, she decides to repeat the exercise the following year. Unfortunately there is a pandemic, and all the students are sent into lock-down at home. So, the teacher assigns the fifty students by lot into two groups, and emails one group the traditional book, and the other the innovative text. She teaches all the students on line as one cohort: each lesson giving them a mini-lecture, then setting them some reading from their (assigned) book, and a set of questions to work through using the text, asking them to upload their individual answers for her to see.

With regard to experimental method, in the first cohort she has only two independent units of analysis – so she may note that the average outcome scores are higher in one group, but cannot read too much into that. However, in the second year, the fifty students can be considered to be learning independently, and as they have been randomly assigned to conditions, she can treat the assessment scores as being from 25 units of analysis in each condition (and so may sensibly apply statistics to see if there is a statistically significant different in outcomes).

⁵ Inferential statistical tests are usually used to see if the difference in outcomes across conditions is 'significant'. Perhaps the average score in a class with an innovation is 5.6, compared with an average score in the control class of 5.1. The average score is higher in the experimental condition, but is the difference enough to matter?

Well, actually, if the question is whether the difference is big enough to likely to make a difference in practice then researchers should calculate the 'effect size' which will suggest whether the difference found should be considered small, moderate or large. This should ideally be calculated regardless of whether inferential statistics are being used or not.

Inferential statistical tests are often used to see if the result is generalisable to the wider population – but, as suggested above, this is strictly only valid if the population of interest have been randomly sampled – which virtually never happens in educational studies as it is usually not feasible.

Often researchers will still do the calculation, based on the sets of outcome scores in the two conditions, to see if they can claim a statistically significant difference – but the test will only suggest how likely or unlikely the difference between the outcomes is, if the units of analysis have been randomly assigned to the conditions. So, if there are 50 learners each randomly assigned to experimental or control condition this makes sense. That is sometimes the case, but nearly always the researchers work with existing classes and do not have the option of randomly mixing the students up. [See the example in the previous note ^4.] In such a situation, the stats. are not informative. (That does not stop them often being reported in published accounts as if they are useful.)

⁶ That is, if it possible to address such complications as participant expectations, and equitable teacher-familiarity with the different conditions they are assigned to (Taber, 2019).

Read about expectancy effects

⁷ A usual ethical expectation is that participants voluntarily (without duress) offer informed consent to participate.

Read about voluntary informed consent

Is your heart in the research?

Someone else's research, that is

Keith S. Taber

Imagine you have a painful and debilitating illness. Your specialist tells you there is no conventional treatment known to help. However, there is a new – experimental – procedure: a surgery that may offer relief. But it has not yet been fully tested. If you are prepared to sign up for a study to evaluate this new procedure, then you can undergo surgery.

You are put under and wheeled into the operating theatre. Whilst you experience – rather, do not experience – the deep, sleepless rest of anaesthesia, the surgeon saws through your breastbone, prises open your ribcage with a retractor (hopefully avoiding breaking any ribs),
reaches in, and gently lifts up your heart.

The surgeon, pauses, perhaps counts to five, then carefully replaces your heart between the lungs. The ribcage is closed, and you are sown-up without any actual medical intervention. You had been randomly assigned to the control group.

How can we test whether surgical interventions are really effective without blind controls?

Is it right to carry out sham operations on sick people just for the sake of research?

Where is the balance of interests?

(Image from Pixabay)

Research ethics

A key aspect of planning, executing and reviewing research is ethical scrutiny. Planning, obviously, needs to take into account ethical considerations and guidelines. But even the best laid plans 'of mice and men' (or, of, say, people investigating mice) may not allow for all eventualities (after all, if we knew what was going to happen for sure in a study, it would not be research – and it would be unethical to spend precious public resources on the study), so the ethical imperative does not stop once we have got approval and permissions. And even then, we may find that we cannot fully mitigate for unexpected eventualities – which is something to be reported and discussed to help inform future research.

Read about research ethics

When preparing students setting out on research, instruction about research ethics is vital. It is possible to teach about rules, and policies, and guidelines and procedures – but real research contexts are often complex, and ethical thinking cannot be algorithmic or a matter of adopting slogans and following heuristics. In my teaching I would include discussion of past cases of research studies that raised ethical questions for students to discuss and consider.

One might think that as research ethics is so important, it would be difficult to find many published studies which were not exemplars of good practice – but attitudes to, and guidance on, ethics have developed over time, and there are many past studies which, if not clearly unethical in today's terms, at least present problematic cases. (That is without the 'doublethink' that allows some contemporary researchers to, in a single paper, both claim active learning methods should be studied because it is known that passive learning activities are not effective, yet then report how they required teachers to instruct classes through passive learning to act as control groups.)

Indeed, ethical decision-making may not always be straight-forward – as it often means balancing different considerations, and at a point where any hoped-for potential benefits of the research must remain uncertain.

Pretending to operate on ill patients

I recently came across an example of a medical study which I thought raised some serious questions, and which I might well have included in my teaching of research ethics as a case for discussion, had I known about before I retired.

The research apparently involved surgeons opening up a patient's ribcage (not a trivial procedure), and lifting out the person's heart in order to carry out a surgical intervention…or not,

"In the late 1950s and early 60s two different surgical teams, one in Kansas City and one in Seattle, did double-blind trials of a ligation procedure – the closing of a duct or tube using a clip – for very ill patients suffering from severe angina, a condition in which pain radiates from the chest to the outer extremities as a result of poor blood supply to the heart. The surgeons were not told until they arrived in the operating theatre which patients were to receive a real ligation and which were not. All the patients, whether or not they were getting the procedure, had their chest cracked open and their heart lifted out. But only half the patients actually had their arteries rerouted so that their blood could more efficiently bathe its pump …"
Slater, 2018

The quote is taken from a book by Lauren Slater which sets out a history of drug use in psychiatry. Slater is a psychotherapist who has written a number of books about aspects of mental health conditions and treatments.

Fair testing

In order to make a fair experiment, the double-blind procedure sought to treat the treatment and control group the same in all respects, apart from the actual procedure of ligation of selected blood vessels that comprised the mooted intervention. The patients did not know (at least, in one of the studies) they might not have the real operation. Their physicians were not told who was getting the treatment. Even the surgeons only found out who was in each group when the patient arrived in theatre.

It was necessary for those in the control group to think they were having an intervention, and to undergo the sham surgery, so that they formed a fair comparison with those who got the ligation.

Read about control of variables

It was necessary to have double-blind study (neither the patients themselves, nor the physicians looking after them, were told which patients were, and which were not, getting the treatment), because there is a great deal of research which shows that people's beliefs and expectations make substantial differences to outcomes. This is a real problem in educational research when researchers want to test classroom practices such as new teaching schemes or resources or innovative pedagogies (Taber, 2019).The teacher almost certainly knows whether she is teaching the experimental or control group, and usually the students have a pretty good idea. (If every previous lesson has been based on teacher presentations and note-taking, and suddenly they are doing group discussion work and making videos, they are likely to notice.)

Read about expectancy effects

It was important to undertake a study, because there was not clear objective evidence to show whether the new procedure actually improved patient outcomes (or possibly even made matters worst). Doctors reported seeing treated patients do better – but could only guess how they might have done without surgery. Without proper studies, many thousands or people might ultimately undergo an ineffective surgery, with all the associated risks and costs, without getting any benefit.

Simply comparing treated patients with matched untreated patients would not do the job, as there can be a strong placebo effect of believing one is getting a treatment. (It is likely that at least some alternative therapies largely work because a practitioner with good social skills spends time engaging with the patient and their concerns, and the client expects a positive outcome.)

If any positive effects of heart surgery were due to the placebo effect, then perhaps a highly coloured sugar pill prescribed with confidence by a physician could have the same effect without operating theatres, surgical teams, hospital stays… (For that matter, a faith healer who pretended to operate without actually breaking the skin, and revealed a piece of material {perhaps concealed in a pocket or sleeve} presented as an extracted mass of diseased tissue or a foreign body, would be just as effective if the patient believed in the procedure.)

So, I understood the logic here.

Do no harm

All the same – this seemed an extreme intervention. Even today, anaesthesia is not very well understood in detail: it involves giving a patient drugs that could kill them in carefully controlled sub-lethal doses – when how much would actually be lethal (and what would be insufficient to fully sedate) varies from person to person. There are always risks involved.

"All the patients, whether or not they were getting the procedure had their chest cracked open and their heart lifted out."

(Image by Starllyte from Pixabay)

Open heart surgery exposes someone to infection risks. Cracking open the chest is a big deal. It can take two months for the disrupted tissues to heal. Did the research really require opening up the chest and lifting the heart for the control group?

Could this really ever have been considered ethical?

I might have been much more cynical had I not known of other, hm, questionable medical studies. I recall hearing a BBC radio documentary in the 1990s about American physicians who deliberately gave patients radioactive materials without their knowledge, just to to explore the effects. Perhaps most infamously there was the Tuskegee Syphilis study where United States medical authorities followed the development of disease over decades without revealing the full nature of the study, or trying to treat any of those infected. Compared with these violations, the angina surgery research seemed tame.

But do not believe everything you read…

According to the notes at the back of Slater's book, her reference was another secondary source (Moerman, 2002) – that is someone writing about what the research reports said, not those actual 'primary' accounts in the research journals.

So, I looked on-line for the original accounts. I found a 1959 study, by a team from the University of Washington School of Medicine. They explained that:

"Considerable relief of symptoms has been reported for patient with angina pectoris subjected to bilateral ligation of the internal mammary arteries. The physiologic basis for the relief of angina afforded by this rather simple operation is not clear."
Cobb, Thomas, Dillard, Merendino & Bruce, 1959

It was not clear why clamping these blood vessels in the chest should make a substantial difference to blood flow to the heart muscles – despite various studies which had subjected a range of dogs (who were not complaining of the symptoms of angina, and did not need any surgery) to surgical interventions followed by invasive procedures in order to measure any modifications in blood flow (Blair, Roth & Zintel, 1960).

Would you like your aorta clamped, and the blood drained from the left side of your heart, for the sake of a research study?

That raises another ethical issue – the extent of pain and suffering and morbidity it is fair to inflect on non-human animals (which are never perfect models for human anatomy and physiology) to progress human medicine. Some studies explored the details of blood circulation in dogs. Would you like your aorta clamped, and the blood drained from the left side of your heart, for the sake of a research study? Moreover, in order to test the effectiveness of the ligation procedure, in some studies healthy dogs had to have the blood supply to the heart muscles disrupted to given them similar compromised heart function as the human angina sufferers. ¹

But, hang on a moment. I think I passed over something rather important in that last quote: "this rather simple operation"?

"Considerable relief of symptoms has been reported for patient with angina pectoris subjected to bilateral ligation of the internal mammary arteries. The physiologic basis for the relief of angina afforded by this rather simple operation is not clear."

Cobb and colleagues' account of the procedure contradicted one of my assumptions,

At the time of operation, which was performed under local anesthesia [anaesthesia], the surgeon was handed a randomly selected envelope, which contained a card instructing him whether or not to ligate the internal mammary arteries after they had been isolated.
Cobb et al, 1959

It seems my inference that the procedure was carried out under general anaesthetic was wrong. Never assume! Surgery under local anaesthetic is not a trivial enterprise, but carries much less risk than general anaesthetic.

Yet, surely, even back then, no surgeon was going to open up the chest and handle the heart under a local anaesthetic? Cobb and colleagues wrote:

"The surgical procedures commonly used in the therapy of coronary-artery disease have previously been "major" operations utilizing thoracotomy and accompanied by some morbidity and a definite mortality. … With the advent of internal-mammary-artery ligation and its alleged benefit, a unique opportunity for applying the principles of a double-blind evaluation to a surgical procedure has been afforded
Cobb, Thomas, Dillard, Merendino & Bruce, 1959

So, the researchers were arguing that, previously, surgical interventions for this condition were major operations that did involve opening up the chest (thorax) – thoracotomy – where sham surgery would not have been ethical; but the new procedure they were testing – "this rather simple operation" was different.

Effects of internal-mammary-artery ligation on 17 patients with angina pectoris were evaluated by a double-blind technic. Eight patients had their internal mammary arteries ligated; 9 had skin incisions only.
Cobb et al, 1959

They describe "a 'placebo' procedure consisting of parasternal skin incisions"– that is some cuts were made into the skin next to the breast bone. Skin incisions are somewhat short of open heart surgery.

The description given by the Kansas team (from the Departments of Medicine and Surgery, University of Kansas Medical Center, Kansas City) also differs from Slater's third-hand account in this important way:

"The patients were operated on under local anesthesia. The surgeon, by random sampling, selected those in whom bilateral internal mammary artery and vein ligation (second interspace) was to be carried out and those in whom a sham procedure was to be performed. The sham procedure consisted of a similar skin incision with exposure of the internal mammary vessels, but without ligation."
Dimond, Kittle & Crocket, 1960

This description of the surgery seemed quite different from that offered by Slater.

These teams seemed to be reporting a procedure that could be carried out without exposing the lungs or the heart and opening their protective covers ("in this technique…the pericardium and pleura are not entered or disturbed", Glover, et al, 1957), and which could be superficially forged by making a few cuts into the skin.

"The performance of bilateral division of the internal mammary arteries as compared to other surgical procedures for cardiac disease is safe, simple and innocuous in capable hands."
Glover, Kitchell, Kyle, Davila & Trout, 1958

The surgery involved making cuts into the skin of the chest to access, and close off, arteries taking blood to (more superficial) chest areas in the hope it would allow more to flow to the heart muscles; the sham surgery, the placebo, involved making similar incisions, but without proceeding to change the pattern of arterial blood flow.

The sham surgery did not require general anaesthesia and involved relatively superficial wounds – and offered a research technique that did not need to cause suffering to, and the sacrifice of, perfectly healthy dogs. So, that's all ethical then?

The first hand research reports at least give a different impression of the balance of costs and potential benefits to stakeholders than I had originally drawn from Lauren Slater's account.

Getting consent for sham surgery

A key requirement for ethical research with human participants is being offered voluntary informed consent. Unlike dogs, humans can assent to research procedures, and it is generally considered that research should not be undertaken without such consent.

Read about voluntary informed consent

Of course, there is nuance and complication. The kind of research where investigators drop large denomination notes to test the honesty of passers by – where the 'participants' are in a public place and will not be identified or identifiable – is not usually seen as needing such consent (which would clearly undermine any possibility of getting authentic results). But is it acceptable to observe people using public toilets without their knowledge and consent (as was described in one published study I used as a teaching example)?

The extent to which a lay person can fully understand the logic and procedures explained to them when seeking consent can vary. The extent to which most participants would need, or even want to, know full details of the study can vary. When children of various ages are are involved, the extent to which consent can be given on their behalf by a parent or teachers raises interesting questions.

"I'm looking for volunteers to have a procedure designed to make it look like you've had surgery"

Image by mohamed_hassan from Pixabay

There is much nuance and many complications – and this is an area researchers needs to give very careful consideration.

How many ill patients would volunteer for sham surgery to help someone else's research?
Would that answer change, if the procedure being tested would later be offered to them?
What about volunteering for a study where you have a 50-50 chance of getting the real surgery or the placebo treatment?

In Cobb's study, the participants had all volunteered – but we might wonder if the extent of the information they were given amounted to what was required for informed consent,

The subjects were informed of the fact that this procedure had not been proved to be of value, and yet many were aware of the enthusiastic report published in the Reader's Digest. The patients were told only that they were participating in an evaluation of this operation; they were not informed of the double-blind nature of the study.
Cobb et al, 1959

So, it seems the patients thought they were having an operation that had been mooted to help angina sufferers – and indeed some of them were, but others just got taken into surgery to get a few wounds that suggested something more substantive had been done.

Was that ethical? (I doubt it would be allowed anywhere today?)

The outcome of these studies was that although the patients getting the ligation surgery did appear to get relief from their angina – so did those just getting the skin incisions. The placebo seemed just as good as the re-plumbing.

In hindsight, does this make the studies more worthwhile and seem more ethical? This research has probably prevented a great many people having an operation to have some of their vascular system blocked when that does not seem to make any difference to angina. Does that advance in medical knowledge justify the deceit involved in leading people to think they would get an experimental surgical treatment when they might just get an experimental control treatment?

Ethical principles and guidelines can helps us judge the merits of study

Coda – what did the middle man have to say?

I wondered how a relatively minor sham procedure under local anaesthetic became characterised as "the patients, whether or not they were getting the procedure had their chest cracked open and their heart lifted out" – a description which gave a vivid impression of a major intervention.

The heart is pretty well integrated into the body – how easy is it to life an intact, fully connected, working heart out of position?

Image by HANSUAN FABREGAS from Pixabay

I wondered to what extent it would even be possible to lift the heart out from the chest whilst it remained connected with the major vessels passing the blood it was pumping, and the nerves supplying it, and the vessels supplying blood to its own muscles (the ones that were considered compromised enough to make the treatment being tested worth considering). Some sources I found on-line referred to the heart being 'lifted' during open-heart procedures to give the surgeon access to specific sites: but that did not mean taking the heart out of the body. Having the heart 'lifted out' seemed more akin to Aztec sacrificial rites than medical treatment.

Although all surgery involves some risk, the actual procedure being investigated seemed of relatively routine nature. I actually attended a 'minor' operation which involved cutting into the chest when my late wife was prepared for kidney dialysis. Usually a site for venal access is prepared in the arm well in advance, but it was decided my wife needed to be put on dialysis urgently. A temporary hole was cut into her neck to allow the surgeon to connect a tube (a central venous catheter) to a vein, and another hole into her chest so that the catheter would exit in her chest, where the tap could be kept sterile, bandaged to the chest. This was clearly not considered a high risk operation (which is not to say I think I could have coped with having this done to me!) as I was asked by the doctors to stay in the room with my wife during the procedure, and I did not need to 'scrub' or 'gown up'.

Bilateral internal mammary artery ligation seemed a procedure on that kind of level, accessing blood vessels through incisions made in the skin. However, if Lauren Slater had read up some of the earlier procedures that did require opening the chest, or if she had read the papers describing how the dogs were investigated to trace blood flow through connected vessels, measure changes in flow, and prepare them for induced heart conditions, I could appreciate the potential for confusion. Yet she did not cite the primary research, but rather Daniel Moerman, an Emeritus Professor of Anthropology at University of Michigan-Dearborn, who has written a book about placebo treatments in medicine.

Moerman does write about the bilateral internal mammary artery ligation, and the two sham surgery studies I found in my search. Moerman describes the operation:

"It was quite simple, and since the arteries were not deep in the body, could be performed under local anaesthetic."
Moerman, 2002

He also refers to the subjective reports on one of the patients assigned to the placebo condition in one of the studies, who claimed to feel much better immediately after the procedure:

"This patient's arteries were not ligated…But he did have two scars on his chest…"
Moerman, 2002

But nobody cracked open his chest, and no one handled his heart.

There are still ethical issues here, but understanding the true (almost superficial) nature of the sham surgery clearly changes the balance of concerns. If there is a moral to this article, it is perhaps the importance of being fully informed before reaching judgement about the ethics of a research study.

Work cited:

Blair, C. R., Roth, R. F., & Zintel, H. A. (1960). Measurement of coronary artery blood-flow following experimental ligation of the internal mammary artery. Annals of Surgery, 152(2), 325.
Cobb, L. A., Thomas, G. I., Dillard, D. H., Merendino, K. A., & Bruce, R. A. (1959). An evaluation of internal-mammary-artery ligation by a double-blind technic. New England Journal of Medicine, 260(22), 1115-1118.
Dimond, E. G., Kittle, C. F., & Crockett, J. E. (1960). Comparison of internal mammary artery ligation and sham operation for angina pectoris. The American Journal of Cardiology, 5(4), 483-486.
Glover, R. P., Davila, J. C., Kyle, R. H., Beard, J. C., Trout, R. G., & Kitchell, J. R. (1957). Ligation of the internal mammary arteries as a means of increasing blood supply to the myocardium. Journal of Thoracic Surgery, 34(5), 661-678. https://doi.org/https://doi.org/10.1016/S0096-5588(20)30315-9
Glover, R. P., Kitchell, J. R., Kyle, R. H., Davila, J. C., & Trout, R. G. (1958). Experiences with Myocardial Revascularization By Division of the Internal Mammary Arteries. Diseases of the Chest, 33(6), 637-657. https://doi.org/https://doi.org/10.1378/chest.33.6.637
Moerman, D. E. (2002). Meaning, Medicine, and the "Placebo Effect". Cambridge University Press Cambridge.
Slater, Lauren (2018) The Drugs that Changed our Minds. The history of psychiatry in ten treatments. London. Simon & Schuster
Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058 [Download this paper.]

Note:

¹ To find out if the ligation procedure protected a dog required stressing the blood supply to the heart itself,

"An attempt has been made to evaluate the degree of protection preliminary ligation of the internal mammary artery may afford the experimental animal when subjected to the production of sudden, acute myocardial infarction by ligation of the anterior descending coronary artery at its origin. …

It was hoped that survival in the control group would approximate 30 per cent so that infarct size could be compared with that of the "protected" group of animals. The "protected" group of dogs were treated in the same manner but in these the internal mammary arteries were ligated immediately before, at 24 hours, and at 48 hours before ligation of the anterior descending coronary.

In 14 control dogs, the anterior descending coronary artery with the aforementioned branch to the anterolateral aspect of the left ventricle was ligated. Nine of these animals went into ventricular fibrillation and died within 5 to 20 minutes. Attempts to resuscitate them by defibrillation and massage were to no avail. Four others died within 24 hours. One dog lived 2 weeks and died in pulmonary edema."
Glover, Davila, Kyle, Beard, Trout & Kitchell, 1957

Pulmonary oedema involves fluid build up in the lungs that restricts gaseous exchange and prevents effective breathing. The dog that survived longest (if it was kept conscious) will have experienced death as if by slow suffocation or drowning.

Why ask teachers to 'transmit' knowledge…

…if you believe that "knowledge is constructed in the minds of students"?

Keith S. Taber

While the students in the experimental treatment undertook open-ended enquiry, the learners in the control condition undertook practical work to demonstrate what they had already been told was the case – a rhetorical exercise that reflected the research study they were participating in

A team of researchers chose to compare a teaching approach they believed met the requirements for good science instruction, and which they knew had already been demonstrated effective pedagogy in other studies, with teaching they believed was not suitable for bringing about conceptual change.
(Ironically, they chose a research design more akin to the laboratory activities in the substandard control condition, than to the open-ended enquiry that was part of the pedagogy they considered effective!)

An imaginary conversation ¹ with a team of science education researchers.

When we critically read a research paper, we interrogate the design of the study, and the argument for new knowledge claims that are being made. Authors of research papers need to anticipate the kinds of questions readers (editors, reviewers, and the wider readership on publication) will be asking as they try to decide if they find the study convincing.

Read about writing-up research

In effect, there is an asynchronous conversation.

Here I engage in 'an asynchronous conversation' with the authors of a research paper I was interrogating:

What was your study about?

"This study investigated the effect of the Science Writing Heuristic (SWH) approach on grade 9 students' understanding of chemical change and mixture concepts [in] a Turkish public high school."
Kingir, Geban & Gunel, 2013

I understand this research was set up as a quasi-experiment – what were the conditions being compared?

"Students in the treatment group were instructed by the SWH approach, while those in the comparison group were instructed with traditionally designed chemistry instruction."
Kingir, Geban & Gunel, 2013

Constructivism

Can you tell me about the theoretical perspective informing this study?

"Constructivism is increasingly influential in guiding student learning around the world. However, as knowledge is constructed in the minds of students, some of their commonsense ideas are personal, stable, and not congruent with the scientifically accepted conceptions… Students' misconceptions [a.k.a. alternative conceptions] and learning difficulties constitute a major barrier for their learning in various chemistry topics"
Kingir, Geban & Gunel, 2013

Read about constructivist pedagogy

Read about alternative conceptions

'Traditional' teaching versus 'constructivist' teaching

So, what does this suggest about so-called traditional teaching?

"Since prior learning is an active agent for student learning, science educators have been focused on changing these misconceptions with scientifically acceptable ideas. In traditional science teaching, it is difficult for the learners to change their misconceptions…According to the conceptual change approach, learning is the interaction between prior knowledge and new information. The process of learning depends on the degree of the integration of prior knowledge with the new information.²"
Kingir, Geban & Gunel, 2013

And does the Science Writing Heuristic Approach contrast to that?

"The Science Writing Heuristic (SWH) approach can be used to promote students' acquisition of scientific concepts. The SWH approach is grounded on the constructivist philosophy because it encourages students to use guided inquiry laboratory activities and collaborative group work to actively negotiate and construct knowledge. The SWH approach successfully integrates inquiry activities, collaborative group work, meaning making via argumentation, and writing-to-learn strategies…

The negotiation activities are the central part of the SWH because learning occurs through the negotiation of ideas. Students negotiate meaning from experimental data and observations through collaboration within and between groups. Moreover, the student template involves the structure of argumentation known as question, claim, and evidence. …Reflective writing scaffolds the integration of new ideas with prior learning. Students focus on how their ideas changed through negotiation and reflective writing, which helps them confront their misconceptions and construct scientifically accepted conceptions"
Kingir, Geban & Gunel, 2013

What is already known about SWH pedagogy?

It seems like the SWH approach should be effective at supporting student learning. So, has this not already been tested?

"There are many international studies investigating the effectiveness of the SWH approach over the traditional approach … [one team] found that student-written reports had evidence of their science learning, metacognitive thinking, and self-reflection. Students presented reasons and arguments in the meaning-making process, and students' self-reflections illustrated the presence of conceptual change about the science concepts.

[another team] asserted that using the SWH laboratory report format in lieu of a traditional laboratory report format was effective on acquisition of scientific conceptions, elimination of misconceptions, and learning difficulties in chemical equilibrium.

[Another team] found that SWH activities led to greater understanding of grade 6 science concepts when compared to traditional activities. The studies conducted at the postsecondary level showed similar results as studies conducted at the elementary level…

[In two studies] it was demonstrated that the SWH approach can be effective on students' acquisition of chemistry concepts. SWH facilitates conceptual change through a set of argument-based inquiry activities. Students negotiate meaning and construct knowledge, reflect on their own understandings through writing, and share and compare their personal meanings with others in a social context"
Kingir, Geban & Gunel, 2013

What was the point of another experimental test of SWH?

So, it seems that from a theoretical point of view, so-called traditional teaching is likely to be ineffective in bringing about conceptual learning in science, whilst a constructivist approach based on the Science Writing Heuristic is likely to support such learning. Moreover, you are aware of a range of existing studies which suggest that in practice the Science Writing Heuristic is indeed an effective basis for science teaching.

So, what was the point of your study?

"The present study aimed to investigate the effect of the SWH approach compared to traditional chemistry instruction on grade 9 students' understanding of chemical change and mixture concepts."
Kingir, Geban & Gunel, 2013

Okay, I would certainly accept that just because a teaching approach has been found effective with one age group, or in one topic, or in one cultural context, we cannot assume those findings can be generalised and will necessarily apply in other teaching contexts (Taber, 2019).

Read about generalisation from studies

What happened in the experimental condition?

So, what happened in the two classes taught in the experimental condition?

"The teacher asked students to form their own small groups (n=5) and introduced to them the SWH approach …they were asked to suggest a beginning question…, write a claim, and support that claim with evidence…

they shared their questions, claims, and evidence in order to construct a group question, claim, and evidence. …each group, in turn, explained their written arguments to the entire class. … the rest of the class asked them questions or refuted something they claimed or argued. …the teacher summarized [and then] engaged students in a discussion about questions, claims, and evidence in order to make students aware of the meaning of those words. The appropriateness of students' evidence for their claims, and the relations among questions, claims, and evidence were also discussed in the classroom…

The teacher then engaged students in a discussion about …chemical change. First, the teacher attempted to elicit students' prior understanding about chemical change through questioning…The teacher asked students to write down what they wanted to learn about chemical change, to share those items within their group, and to prepare an investigation question with a possible test and procedure for the next class. While students constructed their own questions and planned their testing procedure, the teacher circulated through the groups and facilitated students' thinking through questioning…

Each group presented their questions to the class. The teacher and the rest of the class evaluated the quality of the question in relation to the big idea …The groups' procedures were discussed and revised prior to the actual laboratory investigation…each group tested their own questions experimentally…The teacher asked each student to write a claim about what they thought happened, and support that claim with the evidence. The teacher circulated through the classroom, served as a resource person, and asked …questions

…students negotiated their individual claims and evidence within their groups, and constructed group claims and evidence… each group…presented … to the rest of the class."
Kingir, Geban & Gunel, 2013

What happened in the control condition?

Okay, I can see that the experimental groups experienced the kind of learning activities that both educational theory and previous research suggests are likely to engage them and develop their thinking.

So, what did you set up to compare with the Science Writing Heuristic Approach as a fair test of its effectiveness as a pedagogy?

"In the comparison group, the teacher mainly used lecture and discussion[³] methods while teaching chemical change and mixture concepts. The chemistry textbook was the primary source of knowledge in this group. Students were required to read the related topic from the textbook prior to each lesson….The teacher announced the goals of the lesson in advance, wrote the key concepts on the board, and explained each concept by giving examples. During the transmission of knowledge, the teacher and frequently used the board to write chemical formula[e] and equations and draw some figures. In order to ensure that all of the students understood the concepts in the same way, the teacher asked questions…[that] contributed to the creation of a discussion[³] between teacher and students. Then, the teacher summarized the concepts under consideration and prompted students to take notes. Toward the end of the class session, the teacher wrote some algorithmic problems [sic⁴] on the board and asked students to solve those problems individually….the teacher asked a student to come to the board and solve a problem…

The …nature of their laboratory activities was traditional … to verify what students learned in the classroom. Prior to the laboratory session, students were asked to read the procedures of the laboratory experiment in their textbook. At the laboratory, the teacher explained the purpose and procedures of the experiment, and then requested the students to follow the step-by-step instructions for the experiment. Working in groups (n=5), all the students conducted the same experiment in their textbook under the direct control of the teacher. …

The students were asked to record their observations and data. They were not required to reason about the data in a deeper manner. In addition, the teacher asked each group to respond to the questions about the experiment included in their textbook. When students failed to answer those questions, the teacher answered them directly without giving any hint to the students. At the end of the laboratory activity, students were asked to write a laboratory report in traditional format, including purpose, procedure, observations and data, results, and discussion. The teacher asked questions and helped students during the activity to facilitate their connection of laboratory activity with what they learned in the classroom.
Kingir, Geban & Gunel, 2013

The teacher variable

Often in small scale research studies in education, a different teacher teaches each group and so the 'teacher variable' confounds the experiment (Taber, 2019). Here, however, you avoid that problem ⁵, as you had a sample of four classes, and two different teachers were involved, each teaching one class in each condition?

"In order to facilitate the proper instruction of the SWH approach in the treatment group, the teachers were given training sessions about its implementation prior to the study. The teachers were familiar with the traditional instruction. One of the teachers was teaching chemistry for 20 years, while the other was teaching chemistry for 22 years at a high school. The researcher also asked the teachers to teach the comparison group students in the same way they taught before and not to do things specified for the treatment group."
Kingir, Geban & Gunel, 2013

Was this research ethical?

As this is an imaginary conversation, not all of the questions I might like to ask are actually addressed in the paper. In particular, I would love to know how the authors would justify that their study was ethical, considering that the control condition they set up deliberately excluded features of pedagogy that they themselves claim are necessary to support effective science learning:

"In traditional science teaching, it is difficult for the learners to change their misconceptions"

The authors beleive that "learning occurs through the negotiation of ideas", and their experimental condition provides plenty of opportunity for that. The control condition is designed to avoid the explicit elicitation of learners' idea, dialogic talk, or peer interactions when reading, listening, writing notes or undertaking exercises. If the authors' beliefs are correct (and they are broadly consistent with a wide consensus across the global science education research community), then the teaching in the comparison condition is not suitable for facilitating conceptual learning.

Even if we think it is conceivable that highly experienced teachers, working in a national context where constructivist teaching has long been official education policy, had somehow previously managed to only teach in an ineffective way: was it ethical to ask these teachers to teach one of their classes poorly even after providing them with professional development enabling them to adopt a more engaging approach better aligned with our understanding of how science can be effectively taught?

Read about unethical control conditions

Given that the authors already believed that –

"Students' misconceptions and learning difficulties constitute a major barrier for their learning in various chemistry topics"
"knowledge is constructed in the minds of students"
"The process of learning depends on the degree of the integration of prior knowledge with the new information"
"learning occurs through the negotiation of ideas"
"The SWH approach successfully integrates inquiry activities, collaborative group work, meaning making" – A range of previous studies have shown that SWH effectively supports student learning

– why did they not test the SWH approach against existing good practice, rather than implement a control pedagogy they knew should not be effective, so setting up two classes of learners (who do not seem to have been asked to consent to being part of the research) to fail?

Read about the expectation for voluntary informed consent

Why not set up a genuinely informative test of the SWH pedagogy, rather than setting up conditions for manufacturing a forgone conclusion?

When it has already been widely established that a **pedagogy is more effective than standard practice**, there is little point further testing it against what is believed to be *ineffective instruction*.

Read about level of contol in experiments

How can it be ethical to ask teachers to teach in a way that is expected to be ineffective?

transmission of knowledge
follow the step-by-step instructions
not required to reason in a deeper manner
individual working

A rhetorical experiment?

Is this not just a 'rhetorical' experiment engineered to produce a desired outcome (a demonstration), rather than an open-ended enquiry (a genuine experiment)?

Read about rhetorical experiments

A technical question

Any study of a teaching innovation requires the commitment of resources and some disruption of teaching. Therefore any research study which has inherent design faults that will prevent it producing informative outcomes can be seen as a misuse of resources, and an unproductive disruption of school activities, and so, if only in that sense, unethical.

As the research was undertaken with "four intact classes" is it possible to apply any statistical tests that can offer meaningful results, when there are only two units of analysis in each condition? [That is, I think not.]

The researchers claim to have 117 degrees of freedom when applying statistical tests to draw conclusions. They seem to assume that each of the 122 children can be considered to be a separate unit of analysis. But is it reasonable to assume that c.30 children taught together in the same intact class by the same teacher (and working in groups for at least part of the time) are independently experiencing the (experimental or control) treatment?

Surely, the students within a class influence each other's learning (especially during group-work), so the outcomes of statistical tests that rely on treating each learner as an independent unit of analysis are invalid (Taber, 2019). This is especially so in the experimental treatment where dialogue (and "the negotiation of ideas") through group-work, discussion, and argumentation were core parts of the instruction.

Read about units of analysis

Sources cited:

Ausubel, D. P. (1968). Educational Psychology: A cognitive view. Holt, Rinehart & Winston.
Kingir, S., Geban, O., & Gunel, M. (2013). Using the Science Writing Heuristic Approach to Enhance Student Understanding in Chemical Change and Mixture. Research in Science Education, 43(4), 1645-1663. https://doi.org/10.1007/s11165-012-9326-x
Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058 [Download]

Notes:

¹ I have used direct quotes from the published report in Research in Science Education (but I have omitted citations to other papers), with some emphasis added. Please refer to the full report of the study for further details. I have attempted to extract relevant points from the paper to develop an argument here. I have not deliberately distorted the published account by selection and/or omission, but clearly am only reproducing small extracts. I would recommend readers might access the original study in order to make up their own minds.

² The next statement is "If individuals know little about the subject matter, new information is easily embedded in their cognitive structure (assimilation)." This is counter to the common thinking that learning about an unfamiliar topic is more difficult, and learning is made meaningful when it can be related to prior knowledge (Ausubel, 1968).

Read about making the unfamiliar familiar

³ The term 'discussion' might suggest an open-ended exchange of ideas and views. This would be a dialogic technique typical of constructivist approaches. From the wider context its seems likely something more teacher-directed and closed than this was meant here – but this is an interpretation which goes beyond the description available in the original text.

Read about dialogic learning

⁴ Researchers into problem-solving consider that a problem has to require a learner to do more that simply recall and apply previously learned knowledge and techniques – so an 'algorithmic problem' might be considered an oxymoron. However, it is common for teachers to refer to algorithmic exercises as 'problems' even though they do not require going beyond application of existing learning.

⁵ This design does avoid the criticism that one of the teacher may have just been more effective at teaching the topic to this age group, as both teachers teach in both conditions.

This does not entirely remove potential confounds as teachers interact differently with different classes, and with only four teacher-class combinations it could well be that there is better rapport in the two classes in one or other condition. It is very hard to see how this can be addressed (except by having a large enough sample of classes to allow inferential statistics to be used rigorously – which is not feasible in small scale studies).

A potentially more serious issue is 'expectancy' effects. There is much research in education and other social contexts to show that people's beliefs and expectations influence outcomes of studies – and this can make a substantial difference. If the two teachers were unconvinced by the newfangled and progressive approach being tested, then this could undermine their ability to effectively teach that way.

On the other hand, although it is implied that these teachers normally teach in the 'traditional' way, actually constructivist approaches are recommended in Turkey, and are officially sanctioned, and widely taught in teacher education and development courses. If the teachers accepted the arguments for believing the SWH was likely to be more effective at bringing about conceptual learning than the methods they were asked to adopt in the comparison classes, that would further undermine that treatment as a fair control condition.

Read about expectancy effects in research

Again, there is very little researchers can do about this issue as they cannot ensure that teachers participating in research studies are equally confident in the effectivenes of different treatments (and why should they be – the researchers are obviously expecting a substantive difference*), and this is a major problem in studies into teaching innovations (Taber, 2019).

* This is clear from their paper. Is it likely that they would have communicated this to the teachers? "The teachers were given training sessions about [SWH's] implementation prior to the study." Presumably, even if somehow these experienced teachers had previously managed to completely avoid or ignore years of government policy and guidance intending to persuade them of the value of constructivist approaches, the researchers could not have offered effective "training sessions" without explaining the rationales of the overall approach, and for the specific features of the SWH that they wanted teachers to adopt.

Passive learners in unethical control conditions

When 'direct instruction' just becomes poor instruction

Keith S. Taber

An experiment that has been set up to ensure the control condition fails, and so compares an innovation with a substandard teaching condition, can – at best – only show the innovation is not as bad as the substandard teaching

One of the things which angers me when I read research papers is examples of what I think of as 'rhetorical research' that use unethical control conditions (Taber, 2019). That is, educational research which sets up one group of students to be taught in a way that is clearly disadvantages them to ensure the success of an experimental teaching approach,

"I am suggesting that some of the experimental studies reported in the literature are rhetorical in the … sense that the researchers clearly expect to demonstrate a well- established effect, albeit in a specific context where it has not previously been demonstrated. The general form of the question 'will this much-tested teaching approach also work here' is clearly set up expecting the answer 'yes'. Indeed, control conditions may be chosen to give the experiment the best possible chance of producing a positive outcome for the experimental treatment."
Taber, 2019, p.108

This irks me for two reasons. The first, obviously, is that researchers have been prepared to (ab)use learners as 'data fodder' and subject them to poor learning contexts in order to have the best chance of getting positive results for the innovation supposedly being 'tested'. However, it also annoys me as this is inherently a poor research design (and so a poor use of resources) as it severely limits what can be found out. An experiment that compares an innovation with a substandard teaching condition can, at best, show the innovation is not as ineffecitive as the substandard teaching in the control condition; but it cannot tell us if the innovation is at least as effective as existing good practice.

This irritation is compounded when the work I am reading is not some amateur report thrown together for a predatory journal, but an otherwise serious study published in a good research outlet. That was certainly the case for a paper I read today in Research in Science Education (the journal of the Australasian Science Education Research Association) on problem-based learning (Tarhan, Ayar-Kayali, Urek & Acar, 2008).

Rhetorical studies?

Genuine research is undertaken to find something out. The researchers in this enquiry claim:

"This research study aims to examine the effectiveness of a [sic] problem-based learning [PbBL] on 9th grade students' understanding of intermolecular forces (dipole- dipole forces, London dispersion forces and hydrogen bonding)."
Tarhan, et al., 2008, p.285

But they choose to compare PbBL with a teaching approach that they expect to be ineffective. Here the researchers might have asked "how does teaching year 9 students about intermolecular forces though problem-based learning compared with current good practice?" After all, even if PbBL worked quite well, if it is not quite as effective as the way teachers are currently teaching the topic then, all other things being equal, there is no reason to shift to it; whereas if it outperforms even our best current approaches, then there is a reason to recommend it to teachers and roll out associated professional development opportunities.

Problem-based learning (third column) uses a problem (*i.e.*, a task which cannot be solved simply by recalling prior learning or employing an algorithmic routine) as the focus and motivation for learning about a topic

Of course, that over-simplifies the situation, as in education, 'all other things' never are equal (every school, class, teacher…is unique). An approach that works best on average will not work best everywhere. But knowing what works best on average (that is, taken across the diverse range of teaching and learning contexts) is certainly a very useful starting point when teachers want to consider what might work best in their own classrooms.

Rhetorical research is poor research, as it is set up (deliberately or inadvertently) to demonstrate a particular outcome, and, so, has built-in bias. In the case of experimental studies, this often means choosing an ineffective instructional approach for the comparison class. Why else would researchers select a control condition they know is not suitable for bringing about the educational outcomes they are testing for?

Problem-Based Learning in a 9th Grade Chemistry Class

Tarhan and colleagues' study was undertaken in one school with 78 students divided into two groups. One group was taught through a sequence based on problem-based learning that involved students undertaking research in groups, gently supported and steered by the teacher. The approach allowed student dialogue, which is believed to be valuable in learning, and motivated students to be active engaged in enquiry. When such an approach is well judged it has potential to count as 'scaffolding' of learning. This seems a very worthwhile innovation – well worth developing and evaluating.

Of course, work in one school cannot be assumed to generalise elsewhere, and small-scale experimental work of this kind is open to major threats to validity, such as expectancy effects and researcher bias – but this is unfortunately always true of these kinds of studies (which are often all educational researchers are resourced to carry out). Finding out what works best in some educational context at least potentially contributes to building up an overall picture (Taber, 2019). ¹

Why is this rhetorical research?

I consider this rhetoric research because of the claims the authors make at the start of the study:

"Research in science education therefore has focused on applying active learning techniques, which ensure the affective construction of knowledge, prevent the formation of alternate conceptions, and remedy existing alternate conceptions…Other studies suggest that active learning methods increase learning achievement by requiring students to play a more active role in the learning process…According to active learning principles, which emphasise constructivism, students must engage in researching, reasoning, critical thinking, decision making, analysis and synthesis during construction of their knowledge."
Tarhan, et al., 2008, pp.285-286

If they genuinely believed that, then to test the effectiveness of their PbBL activity, Tarhan and colleagues needed to compare it with some other teaching condition that they are confident can "ensure the affective construction of knowledge, prevent the formation of alternate conceptions, and remedy existing alternate conceptions… requir[e] students to play a more active role in the learning process…[and] engage in researching, reasoning, critical thinking, decision making, analysis and synthesis during construction of their knowledge." A failure to do that means that the 'experiment' has been biased – it has been set up to ensure the control condition fails.

Unethical research?

"In most educational research experiments of [this] type…potential harm is likely to be limited to subjecting students (and teachers) to conditions where teaching may be less effective, and perhaps demotivating. This may happen in experimental treatments with genuine innovations (given the nature of research). It can also potentially occur in control conditions if students are subjected to teaching inputs of low effectiveness when better alternatives were available. This may be judged only a modest level of harm, but – given that the whole purpose of experiments to test teaching innovations is to facilitate improvements in teaching effectiveness – this possibility should be taken seriously."
Taber, 2019, p.94

The same teacher taught both classes: "Both of the groups were taught by the same chemistry teacher, who was experienced in active learning and PbBL" (p.288). This would seem to reduce the 'teacher effect' – outcomes being effected because the teacher of one one class being more effective than that of another. (Reduce, rather than eliminate, as different teachers have different styles, skills, and varied expertise: so, most teachers are more suited to, and competent in, some teaching approaches than others.)

So, this teacher was certainly capable of teaching in the ways that Tarhan and colleagues claim as necessary for effective learning ("active learning techniques"). However, the control condition sets up the opposite of active learning, so-called passive learning:

"In this study, the control group was taught the same topics as the experimental group using a teacher-centred traditional didactic lecture format. Teaching strategies were dependent on teacher expression and question-answer format. However, students were passive participants during the lessons and they only listened and took notes as the teacher lectured on the content.

The lesson was begun with teacher explanation about polar and nonpolar covalent bonding. She defined formation of dipole-dipole forces between polar molecules. She explained that because of the difference in electronegativities between the H and Cl atoms for HCl molecule is 0.9, they are polar molecules and there are dipole-dipole forces between HCl molecules. She also stated that the intermolecular dipole-dipole forces are weaker than intramolecular bonds such as covalent and ionic bonding. She gave the example of vaporisation and decomposition of HCl. She explained that while 16 kJ/mol of energy is needed to overcome the intermolecular attraction between HCl molecules in liquid HCl during vaporisation process of HCl, 431 kJ/mol of energy is required to break the covalent bond between the H and Cl atoms in the HCl molecule. In the other lesson, the teacher reminded the students of dipole-dipole forces and then considered London dispersion forces as weak intermolecular forces that arise from the attractive force between instantaneous dipole in nonpolar molecules. She gave the examples of F₂, Cl₂, Br₂, I₂ and said that because the differences in electronegativity for these examples are zero, these molecules are non-polar and had intermolecular London dispersion forces. The effects of molecular size and mass on the strengths of London dispersion forces were discussed on the same examples. She compared the strengths of dipole-dipole forces and London dispersion forces by explaining the differences in melting and boiling points for polar (MgO, HCl and NO) and non-polar molecules (F₂, Cl₂, Br₂, and I₂). The teacher classified London dispersion forces and dipole- dipole as van der Waals forces, and indicated that there are both London dispersion forces and dipole-dipole forces between polar molecules and only London dispersion forces between nonpolar molecules. In the last lesson, teacher called attention to the differences in boiling points of H₂O and H₂S and defined hydrogen bonds as the other intermolecular forces besides dipole-dipole and London dispersion forces. Strengths of hydrogen bonds depending on molecular properties were explained and compared in HF, NH₃ and H₂O. She gave some examples of intermolecular forces in daily life. The lesson was concluded with a comparison of intermolecular forces with each other and intramolecular forces."
Tarhan, et al., 2008, p.293

Lecturing is not ideal for teaching university students. It is generally not suitable for teaching school children (and it is not consistent with what is expected in Turkish schools).

This was a lost opportunity to seriously evaluate the teaching through PbBL by comparing with teaching that followed the national policy recommendations. Moreover, it was a dereliction of the duty that educators should never deliberately disadvantage learners. It is reasonable to experiment with children's learning when you feel there is a good chance of positive outcomes: it is not acceptable to deliberately set up learners to fail (e.g., by organising 'passive' learning when you claim to believe effective learning activities are necessarily 'active').

Isn't this 'direct instruction'?

Now, perhaps the account of the teaching given by Tarhan and colleagues might seem to fit the label of 'direct teaching'. Whilst Tarhan et al. claim constructivist teaching is clearly necessary for effective learning, there are some educators who claim that constructivist approaches are inferior, and a more direct approach, 'direct instruction', is more likely to lead to learning gains.

This has been a lively debate, but often the various commentators use terminology differently and argue across each other (Taber, 2010). The proponents of direct instruction often criticise teaching that expects learners to take nearly all the responsibility for learning, with minimal teacher support. I would also criticise that (except perhaps in the case of graduate research students once they have demonstrated their competence, including knowing when to seek supervisory guidance). That is quite unlike genuine constructivist teaching which is optimally guided (Taber, 2011): where the teacher manages activities, constantly monitors learner progress, and intervenes with various forms of direction and support as needed. Tarhan and colleagues' description of their problem-based learning experimental condition appears to have had this kind of guidance:

"The teacher visited each group briefly, and steered students appropriately by using some guiding questions and encouraging them to generate their hypothesis. The teacher also stimulated the students to gain more information on topics such as the polar structure of molecules, differences in electronegativity, electron number, atom size and the relationship between these parameters and melting-boiling points…The teacher encouraged students to discuss the differences in melting and boiling points for polar and non-polar molecules. The students came up with [their] research questions under the guidance of the teacher…"
Tarhan, et al., 2008, pp.290-291

By contrast, descriptions of effective direct instruction do involve tightly planned teaching with carefully scripted teacher moves of the kind quoted in the account, above, of the control condition. (But any wise teacher knows that lessons can only be scripted as a provisional plan: the teacher has to constantly check the learners are making sense of teaching as intended, and must be prepared to change pace, repeat sections, re-order or substitute activities, invent new analogies and examples, and so forth.)

However, this instruction is not simply a one-way transfer of information, but rather a teacher-led process that engages students in active learning to process the material being introduced by the teacher. If this is done by breaking the material into manageable learning quanta, each of which students engage with in dialogic learning activities before preceding to the next, then this is constructivist teaching (even if it may also be considered by some as 'direct instruction'!)

Effective teaching moves between teacher input and student activities and is not just the teacher communicating information to the learners.

By contrast, the lecture format adopted by Tarhan's team was based on the teacher offering a multi-step argument (delivered over several lessons) and asking the learners to follow and retain an extensive presentation.

"The lesson was begun with teacher explanation …

She defined …

She explained…

She also stated…

She gave the example …

She explained that …

the teacher reminded the students …

She gave the examples of …

She compared…

The teacher classified …

and indicated that …

[the] teacher called attention to …

She gave some examples of …"
Tarhan, et al., 2008, p.293

This is a description of the transmission of information through a communication channel: not an account of teaching which engages with students' thinking and guides them to new understandings.

Ethical review

Despite the paper having been published in a major journal, Research in Science Education, there seems to be no mention that the study design has been through any kind of institutional ethical review before the research began. Moreover, there is no reference to the learners or their parents/guardians having been asked for, or having given, voluntary, informed, consent, as is usually required in research with human participants. Indeed Tarhen and colleagues refer to the children as the 'subjects' of their research, not participants in their study.

Perhaps ethical review was not expected in the national context (at least, in 2008). Certainly, it is difficult to imagine how voluntary, informed, consent would be obtained if parents were to be informed that half of the learners would be deliberately subject to a teaching approach the researchers claim lacks any of the features "students must engage in…during construction of their knowledge".

PbBL is better than…deliberately teaching in a way designed to limit learning

Tarhan and colleagues, unsurprisingly, report that on a post-test the students who were taught through PbBL out-performed these students who were lectured at. It would have been very surprising (and so potentially more interesting, and, perhaps, even useful, research!) had they found anything else, given the way the research was biased.

So, to summarise:

At the outset of the paper it is reported that it is already established that effective learning requires students to engage in active learning tasks.
Students in the experimental conditions undertook learning through a PbBL sequence designed to engage them in active learning.
Students in the control condition were subject to a sequence of lecturing inputs designed to ensure they were passive.
Students in the active learning condition outperformed the students in the passive learning condition

Which I suggest can be considered both rhetorical research, and unethical.

The study can be considered both rhetorical and unfair to the learners assigned to be in the control group

Read about rhetorical experiments

Read about unethical control conditions

Work cited:

Taber, K. S. (2010). Constructivism and direct instruction as competing instructional paradigms: An essay review. Education Review, 13(8), 1-44. [Download the article here]
Taber, K. S. (2011). Constructivism as educational theory: Contingency in learning, and optimally guided instruction. In J. Hassaskhah (Ed.), Educational Theory (pp. 39-61). New York: Nova [Download the chapter here]
Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058 [The author's manuscript version is available for download.]
Tarhan, L., Ayar-Kayali, H., Urek, R. O., & Acar, B. (2008). Problem-Based Learning in 9th Grade Chemistry Class: 'Intermolecular Forces'. Research in Science Education, 38(3), 285-300. https://doi.org/10.1007/s11165-007-9050-0

Note:

¹ There is a major issue which is often ignored in studies of his type (where a pedagogical innovation is trialled in a single school area, school or classroom). Finding that problem-based learning (or whatever) is effective in one school when teaching one topic to one year group does not allow us to generalise to other classrooms, schools, country, educational level, topics and disciplines.

Indeed, as every school, every teacher, every class, etc., is unique in some ways, it might be argued that one only really finds out if an approach will work well 'here' by trying it out 'here' – and whether it is universally applicable by trying it everywhere. Clearly academic researchers cannot carry out such a programme, but individual teachers and departments can try out promising approaches for themselves (i.e., context-directed research, such as 'action research').

We might ask if there is any point in researchers carrying out studies of the type discussed in this article, there they start by saying an approach has been widely demonstrated, and then test it in what seems an arbitrarily chosen (or, more likely, convenient) curriculum and classroom context, given that we cannot generalise from individual studies, and it is not viable to test every possible context.

However, there are some sensible guidelines for how series of such studies into the same type of pedagogic innovation in different contexts can be more useful in (a) helping determine the range of contexts where an approach is effective (through what we might call 'incremental generalisation'), and (b) document the research contexts is sufficient detail to support readers in making judgements about the degree of similarity with their own teaching context (Taber, 2019).

Read about replication studies

Read about incremental generalisation

Didactic control conditions

Another ethically questionable science education experiment?

Keith S. Taber

This seems to be a rhetorical experiment where an educational treatment that is already known to be effective is 'tested' to demonstrate that it is more effective than suboptimal teaching – by asking a teacher to constrain her teaching to students assigned to be an unethical comparison condition

one group of students were deliberately disadvantaged by asking an experienced and skilled teacher to teach in a way all concerned knew was sub-optimal so as to provide a low base line that would be outperformed by the intervention, simply to replicate a much demonstrated finding

In a scientific experiment, an intervention is made into the natural state of affairs to see if it produces a hypothesised change. A key idea in experimental research is control of variables: in the ideal experiment only one thing is changed. In the control condition all relevant variables are fixed so that there is a fair test between the experimental treatment and the control.

Although there are many published experimental studies in education, such research can rarely claim to have fully controlled all potentially relevant variables: there are (nearly always, always?) confounding factors that simply can not be controlled.

Read about confounding variables

Experimental research in education, then, (nearly always, always?) requires some compromising of the pure experimental method.

Where those compromises are substantial, we might ask if experiment was the wrong choice of methodology: even if a good experiment is often the best way to test an idea, a bad experiment may be less informative than, for example, a good case study.

That is primarily a methodological matter, but testing educational innovations and using control conditions in educational studies also raises ethical issues. After all, an experiment means experimenting with real learners' educational experiences. This can certainly be sometimes justified – but there is (or should be) an ethical imperative:

researchers should never ask learners to participate in a study condition they have good reason to expect will damage their opportunities to learn.

If researchers want to test a genuinely innovative teaching approach or learning resource, then they have to be confident it has a reasonable chance of being effective before asking learners to participate in a study where they will be subjected to an untested teaching input.

It is equally the case that students assigned to a control condition should never be deliberately subjected to inferior teaching simply in order to help make a strong contrast with an experimental approach being tested. Yet, reading some studies leads to a strong impression that some researchers do seek to constrain teaching to a control group to help bias studies towards the innovation being tested (Taber, 2019). That is, such studies are not genuinely objective, open-minded investigations to test a hypothesis, but 'rhetorical' studies set up to confirm and demonstrate the researchers' prior assumptions. We might say these studies do not reflect true scientific values.

A general scheme for a 'rhetorical experiment'

Read about rhetorical experiments

I have raised this issue in the research literature (Taber, 2019), so when I read experimental studies in education I am minded to check see that any control condition has been set up with a concern to ensure that the interests of all study participants (in both experimental and control conditions) have been properly considered.

Jigsaw cooperative learning in elementary science: physical and chemical changes

I was reading a study called "A jigsaw cooperative learning application in elementary science and technology lessons: physical and chemical changes" (Tarhan, Ayyıldız, Ogunc & Sesen, 2013) published in a respectable research journal (Research in Science & Technological Education).

Tarhan and colleagues adopted a common type of research design, and the journal referees and editor presumably were happy with the design of their study. However, I think the science education community should collectively be more critical about the setting up of control conditions which require students to be deliberately taught in ways that are considered to be less effective (Taber, 2019).

Jigsaw learning involves students working in co-operative groups, and in undertaking peer-teaching

Jigsaw learning is a pedagogic technique which can be seen as a constructivist, student-centred, dialogic, form of 'active learning'. It is based on collaborative groupwork and includes an element of peer-tutoring. In this paper the technique is described as "jigsaw cooperative learning", and the article authors explain that "cooperative learning is an active learning approach in which students work together in small groups to complete an assigned task" (p.185).

Read about jigsaw learning

Random assignment

The study used an experimental design, to compare between learning outcomes in two classes taught the same topic in two different ways. Many studies that compare between two classes are problematic because whole extant classes are assigned to conditions which means that the unit of analysis should be the class (experimental condition, n=1; control condition, n=1). Yet, despite this, such studies commonly analyse results as if each learner was an independent unit of analysis (e.g., experimental condition, n=c.30; control condition, n=c.30) which is necessary to obtain statistical results, but unfortunately means that inferences drawn from those statistics are invalid (Taber, 2019). Such studies offer examples of where there seems little point doing an experiment badly as the very design makes it intrinsically impossible to obtain a (i.e., a valid) statistically significant outcome.

Experimental designs may be categorised as true experiments, quasi-experiments and natural experiments (Taber, 2019).

Tarhan and colleagues, however, randomly assign the learners to the two conditions so can genuinely claim that in their study they have a true experiment: for their study, experimental condition, n=30; control condition, n=31.

Initial equivalence between groups

Assigning students in this way also helped ensure the two groups started from a similar base. Often such experimental studies use a pre-test to compare the groups before teaching. However, often the researchers look for a statistical difference between the groups which does not reach statistical significance (Taber, 2019). That is, if a statistical test shows p≥0.05 (in effect, the initial difference between the groups is not very unlikely to occur by chance) this is taken as evidence of equivalence. That is like saying we will consider two teachers to be of 'equivalent' height as long as there is no more than 30 cm difference in their height!

In effect

'not very different'

is being seen as a synonym for

'near enough the same'

Some analogies for how equivalence is determined in some studies: *read about testing for initial equivalence*

However, the pretest in Tarhan and colleagues' study found that the difference between two groups in performances on the pretest was at a level likely to occur by chance (not simply something more than 5%, but) 87% of the time. This is a much more convincing basis for seeing the two groups as initially similar.

So, there are two ways in which the Tarhan et al. study seemed better thought-through than many small scale experiments in teaching I have read.

Comparing two conditions

The research was carried out with "sixth grade students in a public elementary school in Izmir, Turkey" (p.184). The focus was learning about physical and chemical changes.

The experimental condition

At the outset of the study, the authors suggest it is already known that

"Jigsaw enhances cooperative learning" (p.185)"
"Jigsaw promotes positive attitudes and interests, develops communication skills between students, and increases learning achievement in chemistry" (p.186)
"the jigsaw technique has the potential to improve students' attitude towards science"
development of "students' understanding of chemical equilibrium in a first year general chemistry course [was more successful] in the jigsaw class…than …in the individual learning class"

It seems the approach being tested was already demonstrated to be effective in a range of contexts. Based on the existing research, then, we could already expect well-implemented jigsaw learning to be effective in facilitating student learning.

Similarly, the authors tell the readers that the broader category of cooperative learning has been well established as successful,

"The benefits of cooperative learning have been well documented as being

higher academic achievement,

higher level of reasoning and critical thinking skills,

deeper understanding of learned material,

better attention and less disruptive behavior in class,

more motivation to learn and achieve,

positive attitudes to subject matter,

higher self-esteem and

higher social skills."
Tarhan et al., 2013, p.185

What is there not to like here? So, what was this highly effective teaching approach compared with?

What is being compared?

Tarhan and colleagues tell readers that:

"The experimental group was taught via jigsaw cooperative learning activities developed by the researchers and the control group was taught using the traditional science and technology curriculum."
Tarhan et al., 2013, p.189

A different curriculum?

This seems an unhelpful statement as it does not seem to compare like with like:

condition	curriculum	pedagogy
experimental	?	jigsaw cooperative learning activities developed by the researchers
control	traditional science and technology curriculum	?

A genuine experiment would look to control variables, so would not simultaneously vary both curriculum and pedagogy

The study uses a common test to compare learning in the two conditions, so the study only makes sense as an experimental test of jigsaw learning if the same curriculum is being followed in both conditions. Otherwise, there is no prima facie reason to think that the post-test is equally fair in testing what has been taught in the two conditions. ¹

The control condition

The paper includes an account of the control condition which seems to make it clear that both groups were taught "the same content", which is helpful as to have done otherwise would have seriously undermined the study.

The control group was instructed via a teacher-centered didactic lecture format. Throughout the lesson, the same science and technology teacher presented the same content as for the experimental group to achieve the same learning objectives, which were taught via detailed instruction in the experimental group. This instruction included lectures, discussions and problem solving. During this process, the teacher used the blackboard and asked some questions related to the subject. Students also used a regular textbook. While the instructor explained the subject, the students listened to her and took notes. The instruction was accomplished in the same amount of time as for the experimental group.
Tarhan et al., 2013, p.194

So, it seems:

condition	curriculum	pedagogy
experimental	[by inference: "traditional science and technology curriculum"]	jigsaw cooperative learning activities developed by the researchers
control	traditional science and technology curriculum [the same content as for the experimental group to achieve the same learning objectives]	teacher-centred didactic lecture format: instructor explained the subject and asked questions
	controlled variable	independent variable

An experiment relies on control of variables and would not simultaneously vary both curriculum and pedagogy

The statement is helpful, but might be considered ambiguous as "this instruction which included lectures, discussions and problem solving" seems to relate to what had been "taught via detailed instruction in the experimental group".

But this seems incongruent with the wider textual context. The experimental group were taught by a jigsaw learning technique – not lectures, discussions and problem solving. Yet, for that matter, the experimental group were not taught via 'detailed instruction' if this means the teacher presenting the curriculum content. So, this phrasing seems unhelpfully confusing (to me, at least – presumably, the journal referees and editor thought this was clear enough.)

So, this probably means the "lectures, discussions and problem solving" were part of the control condition where "the teacher used the blackboard and asked some questions related to the subject. Students also used a regular textbook. While the instructor explained the subject, the students listened to her and took notes".

'Lectures' certainly fit with that description.

However, genuine 'discussion' work is a dialogic teaching method and would not seem to fit within a "teacher-centered didactic lecture format". But perhaps 'discussion' simply refers to how the "teacher used the blackboard and asked some questions" that members of the class were invited to answer?

Read about dialogic teaching

Writing-up research is a bit like teaching in that in presenting to a particular audience, one works with a mental model of what that audience already knowns and understands, and how they use specific terms, and this model is never likely to be perfectly accurate:

when teaching, the learners tend to let you know this, whereas,
when writing, this kind of immediate feedback is lacking.

Similarly, problem-solving would not seem to fit within a "teacher-centered didactic lecture format". 'Problem-solving' engages high level cognitive and metacognitive skills because a 'problem' is a task that students are not able to respond to simply by recalling what they have been told and applying learnt algorithms. Problem-solving requires planning and applying strategies to test out ideas and synthesise knowledge. Yet teachers and textbooks commonly refer to simple questions that simply test recall and comprehension, or direct application of learnt techniques, as 'problems' when they are better understood as 'exercises' as they do not pose authentic problems.

The imprecise use of terms that may be understood differently across diverse contexts is characteristic of educational discourse, so Tarhan and colleagues may have simply used the labels that are normally applied in the context where they are working. It should also be noted that as the researchers are based in Turkey they are presumably finding the best English translations they can for the terms used locally.

Read about the challenges of translation in research writing

So, it seems we have:

Experimental condition	in one of the conditions?	Control condition
Jigsaw learning (set out in some detail in the paper) – an example of cooperative learning – an active learning approach in which students work together in small groups	detailed instruction? discussions (=teacher questioning?) problem solving? (=practice exercises?)	teacher-centred didactic lecture format…the teacher used the blackboard and asked some questions…a regular textbook….the instructor explained the subject, the students listened and took notes

The independent variable – teaching methodology

The teacher variable

One of the major problems with some educational experiments comparing different teaching approaches is the confound of the teacher. If

class A is taught through approach 'a' by teacher 1, and
class B is taught through approach 'b' by teacher 2

then even if there is a good case that class A and class B start off as 'equivalent' in terms of readiness to learn about the focal topic then any differences in study outcomes could be as much down to different teachers (and we all know that different teachers are not equivalent!) as different teaching methodology.

At first sight this is easily solved by having the same teacher teach both classes (as in the study discussed here). That certainly seems to help. But, a little thought suggests it is not a foolproof approach (Taber, 2019).

Teachers inevitably have better rapport with some classes than others (even when those classes are shown to be technically 'equivalent') simply because that is the nature of how diverse personalities interact. ³ Even the most professional teachers find they prefer to teach some classes than others, enjoy the teaching more, and seem to get better results (even when the classes are supposed to be equivalent).

In an experiment, there is no reason why the teacher would work better with a class assigned the experimental condition; it might just as well be the control condition. However, this is still a confound and there is no obvious solution to this, except having multiple classes and teachers in each condition such that the statistics can offer guide on whether outcomes are sufficiently unlikely to be able to reasonable discount these types of effect.

Different teachers also have different styles and approaches and skills sets – so the same teacher will not be equally suited to every teaching approach and pedagogy. Again, this does not necessarily advantage the experimental condition, but, again, is something that can only be addressed by having a diverse range of teachers in each condition (Taber, 2019).

So, although we might expect having the same teacher teach both classes is the preferred approach, the same teacher is not exactly the same teacher in different classes or teaching in different ways.

And what do participants expect will happen?

Moreover, expectancy effects can be very influential in education. Expecting something to work, or not work, has been shown to have real effects on outcomes. It may not be true, as some motivational gurus like to pretend, that we can all of us achieve anything if only we believe: but we are more likely to be successful when we believe we can succeed. When confident, we tend to be more motivated, less easily deterred, and (given the human capacity for perceiving with confirmation bias) more likely to judge we are making good progress. So, any research design which communicates to teachers and students (directly, or through the teacher's or researcher's enthusiasm) an expectation of success in some innovation is more likely to lead to success. This is a potential confound that is not even readily addressed by having large numbers of classes and teachers (Taber, 2019)!

Read about expectancy effects

The authors report that

Before implementation of the study, all students and their families were informed about the aims of the study and the privacy of their personal information. Permission for their children attend the study was obtained from all families.
Tarhan et al., 2013, p.194

This is as it should be. School children are not data-fodder for researchers, and they should always be asked for, and give, voluntary informed consent when recruited to join a research project. However, researchers need to open and honest about their work, whilst also being careful about how they present their research aims. We can imagine a possible form of invitation,

We would like you to invite you to be part of a study where some of you will be subject to traditional learning through a teacher-centred didactic lecture format where the teacher will give you notes and ask you questions, and some of you will learn by a different approach that has been shown to enhance learning, promote positive attitudes and interests, develop communication skills, increase achievement, support higher level of reasoning and critical thinking skills, lead to deeper understanding of learned material…
An honest, but unhelpful, briefing for students and parents

If this was how the researchers understood the background to their study, then this would be a fair and honest briefing. Yet, this would clearly set up strong expectations in the student groups!

A suitable teacher

Tarhan and colleagues report that

"A teacher experienced in active learning was trained in how to implement the instruction based on jigsaw cooperative learning. The teacher and researchers discussed the instructional plans before implementing the activities."
Tarhan et al., 2013, p.189

So, the teacher who taught both classes, using an jigsaw cooperative learning in one class and a teacher-centred didactic lecture approach in the other was "experienced in active learning". So, it seems that

the researchers were already convinced that active learning approaches were far superior to teaching via a lecture approach
the teacher had experience in teaching though more engaging, effective student-centred active learning approaches

despite this, a control condition was set-up that required the teacher to, in effect, de-skill, and teach in a way the researchers were well aware research suggested was inferior, for the sake of carrying out an experiment to demonstrate in a specific context what had already been well demonstrated elsewhere.

In other words, it seems that one group of students were deliberately disadvantaged by asking an experienced and skilled teacher to teach in a way all concerned knew was sub-optimal, so as to provide a low base line that would be outperformed by the intervention, simply to replicate a much demonstrated finding. When seen in that way, this is surely unethical research.

The researchers may not have been consciously conceptualising their design in those terms, but it is hard to see this as a fair test of the jigsaw learning approach – it can show it is better than suboptimal teaching, but does not offer a comparison with an example of the kind of teaching that is recommended in the national context where the research took place.

Unethical, but not unusual

I am not seeking to pick out Tarhan and colleagues in particular for designing an unethical study, because they are not unique in adopting this approach (Taber, 2019): indeed, they are following a common formula (an experimental 'paradigm' in the sense the term is used in psychology).

Tarhan and colleagues have produced a study that is interesting and informative, and which seems well planned, and strongly-motivated when considered as part of tradition of such studies. Clearly, the referees and journal editor were not minded to question the procedure. The problem is that as a science education community we have allowed this tradition to continue such that a form of study that was originally genuinely open-ended (in that it examined under-researched teaching approaches of untested efficacy) has not been modified as published study after published study has slowly turned those untested teaching approaches into well-researched and repeatedly demonstrated approaches.

So much so, that such studies are now in danger of simply being rhetorical research – where (as in this case) the authors tell readers at the outset that it is already known that what they are going to test is widely shown to be effective good practice. Rhetorical research is set up to produce an expected result, and so is not authentic research. A real experiment tests a genuine hypothesis rather than demonstrates a commonplace. A question researchers might ask themselves could be

'how surprised would I be if this leads to a negative outcome'?

If the answer is

'that would be very surprising'

then they should consider modifying their research so it is likely to be more than minimally informative.

Finding out that jigsaw learning achieved learning objectives better/as well as/not so well as, say, P-O-E (predict-observe-explain) activities might be worth knowing: that it is better than deliberately constrained teaching does not tell us very much that is not obvious.

I do think this type of research design is highly questionable and takes unfair advantage of students. It fails to meet my suggested guideline that

researchers should never ask learners to participate in a study condition they have good reason to expect will damage their opportunities to learn

The problem of generalisation

Of course, one fair response is that despite all the claims of the superiority of constructivist, active, cooperatative (etc.) learning approaches, the diversity of educational contexts means we can not simply generalise from an experiment in one context and assume the results apply elsewhere.

Read about generalising fr o m research

That is, the research literature shows us that jigsaw learning is an effective teaching approach, but we cannot be certain it will be effective in the particular context of teaching about chemical and physical changes to sixth grade students in a public elementary school in Izmir, Turkey.

Strictly that is true! But we should ask:

do we not know this because

research shows a great variation in whether jigsaw learning is effective or not as it differs according to contexts and conditions
although jigsaw learning has consistently been shown to be effective in many different contexts, no one has yet tested it in the specific case of teaching about chemical and physical changes to sixth grade students in a public elementary school in Izmir, Turkey

It seems clear from the paper that the researchers are presenting the second case (in which case the study would actually be of more interest and importance if had been found that in this context jigsaw learning was not effective).

Given there are very good reasons to expect a positive outcome, there seems no need to 'stack the odds' by using deliberately detrimental control conditions.

Even had situation 1 applied, it seems of limited value to know that jigsaw learning is more effective (in teaching about chemical and physical changes to sixth grade students in a public elementary school in Izmir, Turkey) than an approach we already recognise is suboptimal.

An ethical alternative

This does not mean that there is no value in research that explores well-established teaching approaches in new contexts. However, unless the context is very different from where the approach has already been widely demonstrated, there is little value in comparing it with approaches that are known to be sub-optimal (which in Turkey, a country where constructivist 'reform' teaching approaches are supposed to be the expected standard, seem to often be labelled as 'traditional').

Detailed case studies of the implementation of a reform pedagogy in new contexts that collect rich 'process' data to explore challenges to implementation and to identify especially effective specific practices would surely be more informative? ⁴

If researchers do feel the need to do experiments, then rather than comparing known-to-be-effective approaches with suboptimal approaches hoping to demonstrate what everyone already knows, why not use comparison conditions that really test the innovation. Of course jigsaw learning out performed lecturing in an elementary school – but how might it have compared with another constructivist approach?

I have described the constructivist science teacher as a kind of learning doctor. Like medical doctors, our first tenet should be to do no harm. So, if researchers want to set up experimental comparisons, they have a duty to try to set up two different approaches that they believe are likely to benefit the learners (whichever condition they are assigned to):

not one condition that advantages one group of students
and another which deliberately disadvantages another group of students for the benefit of a 'positive' research outcome.

If you already know the outcome then it is not genuine research – and you need a better research question.

Work cited:

Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058
Leman Tarhan, Yıldızay Ayyıldız, Aylin Ogunc & Burcin Acar Sesen (2013) A jigsaw cooperative learning application in elementary science and technology lessons: physical and chemical changes, Research in Science & Technological Education, 31:2, 184-203, DOI: 10.1080/02635143.2013.811404

Note:

¹ Imagine teaching one class about acids by jigsaw learning, and teaching another about the nervous system by some other pedagogy – and then comparing the pedagogies by administering a test – about acids! The class in the jigsaw condition might well do better, without it being reasonable to assume this reflects more effective pedagogy.

So, I am tempted to read this as simply a drafting/typographical error that has been missed, and suspect the authors intended to refer to something like the traditional approach to teaching the science and technology curriculum. Otherwise the experiment is fatally flawed.

Yet, one purpose of the study was to find out

"Does jigsaw cooperative learning instruction contribute to a better conceptual understanding of 'physical and chemical changes' in sixth grade students compared to the traditional science and technology curriculum?"
Tarhan et al., 2013, p.187

This reads as if the researchers felt the curriculum was not sufficiently matched to what they felt were the most important learning objectives in the topic of physical and chemical changes, so they have undertaken some curriculum development, as well as designed a teaching unit accordingly, to be taught by jigsaw learning pedagogy. If so the experiment is testing

traditional curriculum x traditional pedagogy

vs.

reformed curriculum x innovative pedagogy

making it impossible to disentangle the two components.

This suggests the researchers are testing the combination of curriculum and pedagogy, and doing so with a test biased towards the experimental condition. This seems illogical, but I have actually worked in a project where we faced a similar dilemma. In the epiSTEMe project we designed innovative teaching units for lower secondary science and maths. In both physics units we incorporated innovative aspects to the curriculum.

In the forces unit material on proportionality was introduced, with examples (car stopping distance) normally not taught at that grade level (Y7);
In the electricity unit the normal physics content was embedded in an approach designed to teach aspects of the nature of science.

In the forces unit, the end-of-topic test included material that was included in the project-designed units, but unlikely to be taught in the control classes. There was evidence that on average students in the project classes did better on the test.

In the electricity unit, the nature of science objectives were not tested as these would not necessarily have been included in teaching control classes. On average, there was very little difference in learning about electrical circuits in the two conditions. There was however a very wide range of class performances – oddly just as wide in the experimental condition (where all classes had a common scheme of work, common activities, and common learning materials) as in the control condition where teachers taught the topic in their customary ways.

² It could be read either as

Control	Experimental
The control group was instructed via a teacher-centered didactic lecture format. Throughout the lesson, the same science and technology teacher presented the same content as for the experimental group to achieve the same learning objectives, which were taught via detailed instruction in the experimental group.
	…detailed instruction in the experimental group. This instruction included lectures, discussions and problem solving.
During this process, the teacher used the blackboard and asked some questions related to the subject. Students also used a regular textbook. While the instructor explained the subject, the students listened to her and took notes. The instruction was accomplished in the same amount of time as for the experimental group.

What was 'this instruction' which included lectures, discussions and problem solving?

Control	Experimental
The control group was instructed via a teacher-centered didactic lecture format. Throughout the lesson, the same science and technology teacher presented the same content as for the experimental group to achieve the same learning objectives, which were taught via detailed instruction in the experimental group.
	…detailed instruction in the experimental group.
This [sic] instruction included lectures, discussions and problem solving. During this process, the teacher used the blackboard and asked some questions related to the subject. Students also used a regular textbook. While the instructor explained the subject, the students listened to her and took notes. The instruction was accomplished in the same amount of time as for the experimental group.

What was 'this instruction' which included lectures, discussions and problem solving?

³ A class, of course, is not a person, but a collection of people, so perhaps does not have a 'personality' as such. However, for teachers, classes do take on something akin to a personality.

This is not just an impression. It was pointed out above that if a researcher wants to treat each learner as a unit of analysis (necessary to use inferential statistics when only working with a small number of classes) then learners, not intact classes, should be assigned to conditions. However, even a newly formed class will soon develop something akin to a personality. This will certainly be influenced by individual learners present but develop through the history of their evolving mutual interactions and is not just a function of the sum of their individual characteristics.

So, even when a class is formed by random assignment of learners at the start of a study, it is still strictly questionable whether these students should be seen as independent units for analysis (Taber, 2019).

⁴ I suspect that science educators have a justified high regard for experimental method in the natural sciences, which sometimes blinkers us to its limitations in social contexts where there are myriad interacting variables and limited controls.

Read: Why do natural scientists tend to make poor social scientists?

A case of hybrid research design?

When is "a case study" not a case study? Perhaps when it is (nearly) an experiment?

Keith S. Taber

I read this interesting study exploring learners shifting conceptions of the particulate nature of gases.

Mamombe, C., Mathabathe, K. C., & Gaigher, E. (2020). The influence of an inquiry-based approach on grade four learners' understanding of the particulate nature of matter in the gaseous phase: a case study. EURASIA Journal of Mathematics, Science and Technology Education, 16(1), 1-11. doi:10.29333/ejmste/110391

Key features:

Science curriculum context: the particulate nature of matter in the gaseous phase
Educational context: Grade 4 students in South Africa
Pedagogic context: Teacher-initiated inquiry approach (compared to a 'lecture' condition/treatment)
Methodology: "qualitative pre-test/post-test case study design" – or possibly a quasi-experiment?
Population/sample: the sample comprised 116 students from four grade four classes, two from each of two schools

This study offers some interesting data, providing evidence of how students represent their conceptions of the particulate nature of gases. What most intrigued me about the study was its research design, which seemed to reflect an unusual hybrid of quite distinct methodologies.

In this post I look at whether the study is indeed a case study as the authors suggest, or perhaps a kind of experiment. I also make some comments about the teaching model of the states of matter presented to the learners, and raise the question of whether the comparison condition (lecturing 8-9 year old children about an abstract scientific model) is appropriate, and indeed ethical.

Learners' conceptions of the particulate nature of matter

This paper is well worth reading for anyone who is not familiar with existing research (such as that cited in the paper) describing how children make sense of the particulate nature of matter, something that many find counter-intuitive. As a taster for this, I reproduce here two figures from the paper (which is published open access under a creative common license* that allows sharing and adaption of copyright material with due acknowledgement).

Pre-test data from Mamombe et al, 2020
Post-test data from Mamombe et al, 2020.

Conceptions are internal, and only directly available to the epistemic subject, the person holding the conception. (Indeed, some conceptions may be considered implicit, and so not even available to direct introspection.) In research, participants are asked to represent their understandings in the external 'public space' – often in talk, here by drawing (Taber, 2013). The drawings have to be interpreted by the researchers (during data analysis). In this study the researchers also collected data from group work during learning (in the enquiry condition) and by interviewing students.

What kind of research design is this?

Mamombe and colleagues describe their study as "a qualitative pre-test/post-test case study design with qualitative content analysis to provide more insight into learners' ideas of matter in the gaseous phase" (p. 3), yet it has many features of an experimental study.

The study was

"conducted to explore the influence of inquiry-based education in eliciting learners' understanding of the particulate nature of matter in the gaseous phase"
p.1

The experiment compared two pedagogical treatments :

"inquiry-based teaching…teacher-guided inquiry method" (p.3) guided by "inquiry-based instruction as conceptualized in the 5Es instructional model" (p.5)
"direct instruction…the lecture method" (p.3)

These pedagogic approaches were described:

"In the inquiry lessons learners were given a lot of materials and equipment to work with in various activities to determine answers to the questions about matter in the gaseous phase. The learners in the inquiry lessons made use of their observations and made their own representations of air in different contexts."
"the teacher gave probing questions to learners who worked in groups and constructed different models of their conceptions of matter in the gaseous phase. The learners engaged in discussion and asked the teacher many questions during their group activities. Each group of learners reported their understanding of matter in the gaseous phase to the class"
p.5, p.1

"In the lecture lessons learners did not do any activities. They were taught in a lecturing style and given all the notes and all the necessary drawings.
In the lecture classes the learners were exposed to lecture method which constituted mainly of the teacher telling the learners all they needed to know about the topic PNM [particulate nature of matter]. …During the lecture classes the learners wrote a lot of notes and copied a lot of drawings. Learners were instructed to paste some of the drawings in their books."
pp.5-6

The authors report that,

"The learners were given clear and neat drawings which represent particles in the gaseous, liquid and solid states…The following drawing was copied by learners from the chalkboard."
p.6

Figure used to teach learners in the 'lecture' condition. Figure © 2020 by the authors of the cited paper *

A teaching model of the states of matter

This figure shows increasing separation between particles moving from solid to liquid to gas. It is not a canonical figure, in that the spacing in a liquid is not substantially greater than in a solid (indeed, in ice floating on water the spacing is greater in the solid), whereas the difference in spacing in the two fluid states is under-represented.

Such figures do not show the very important dynamic aspect: that in a solid particles can usually only oscillate around a fixed position (a very low rate of diffusion not withstanding), where in a liquid particles can move around, but movement is restricted by the close arrangement of (and intermolecular forces between) the particles, where in a gas there is a significant mean free path between collisions where particles move with virtually constant velocity. A static figure like this, then, does not show the critical differences in particle interactions which are core to the basic scientific model

Perhaps even more significant, figure 2 suggests there is the same level of order in the three states, whereas the difference in ordering between a solid and liquid is much more significant than any change in particle spacing.

In teaching, choices have to be made about how to represent science (through teaching models) to learners who are usually not ready to take on board the full details and complexity of scientific knowledge. Here, Figure 2 represents a teaching model where it has been decided to emphasise one aspect of the scientific model (particle spacing) by distorting the canonical model, and to neglect other key features of the basic scientific account (particle movement and arrangement).

External teachers taught the classes

The teaching was undertaken by two university lecturers

"Two experienced teachers who are university lecturers and well experienced in teacher education taught the two classes during the intervention. Each experienced teacher taught using the lecture method in one school and using the teacher-guided inquiry method in the other school."
p.3

So, in each school there was one class taught by each approach (enquiry/lecture) by a different visiting teacher, and the teachers 'swapped' the teaching approaches between schools (a sensible measure to balance possible differences between the skills/styles of the two teachers).

The research design included a class in each treatment in each of two schools

An experiment; or a case study?

Although the study compared progression in learning across two teaching treatments using an analysis of learner diagrams, the study also included interviews, as well as learners' "notes during class activities" (which one would expect would be fairly uniform within each class in the 'lecture' treatment).

The outcome

The authors do not consider their study to be an experiment, despite setting up two conditions for teaching, and comparing outcomes between the two conditions, and drawing conclusions accordingly:

"The results of the inquiry classes of the current study revealed a considerable improvement in the learners' drawings…The results of the lecture group were however, contrary to those of the inquiry group. Most learners in the lecture group showed continuous model in their post-intervention results just as they did before the intervention…only a slight improvement was observed in the drawings of the lecture group as compared to their pre-intervention results"
pp.8-9

These statements can be read in two ways – either

a description of events (it just happened that with these particular classes the researchers found better outcomes in the enquiry condition), or
as the basis for a generalised inference.

An experiment would be designed to test a hypothesis (this study does not seem to have an explicit hypothesis, nor explicit research questions). Participants would be assigned randomly to conditions (Taber, 2019), or, at least, classes would be randomly assigned (although then strictly each class should be considered as a single unit of analysis offering much less basis for statistical comparisons). No information is given in the paper on how it was decided which classes would be taught by which treatment.

Representativeness

A study could be carried out with the participation of a complete population of interest (e.g., all of the science teachers in one secondary school), but more commonly a sample is selected from a population of interest. In a true experiment, the sample has to be selected randomly from the population (Taber, 2019) which is seldom possible in educational studies.

The study investigated a sample of 'grade four learners'

In Mamombe and colleagues' study the sample is described. However, there is no explicit reference to the population from which the sample is drawn. Yet the use of the term 'sample' (rather than just, say, 'participants') implies that they did have a population in mind.

The aim of the study is given as to "to explore the influence of inquiry-based education in eliciting learners' understanding of the particulate nature of matter in the gaseous phase" (p.1) which could be considered to imply that the population is 'learners'. The title of the paper could be taken to suggest the population of interests is more specific: "grade four learners". However, the authors make no attempt to argue that their sample is representative of any particular population, and therefore have no basis for statistical generalisation beyond the sample (whether to learners, or to grade four learners, or to grade four learners in RSA, or to grade four learners in farm schools in RSA, or…).

Indeed only descriptive statistics are presented: there is no attempt to use tests of statistical significance to infer whether the difference in outcomes between conditions found in the sample would probably have also been found in the wider population.

(That is inferential stats. are commonly used to suggest 'we found a statistically significant better outcome in one condition in our sample, so in the hypothetical situation that we had been able to include the entire population in out study we would probably have found better mean outcomes in that same condition'.)

This may be one reason why Mamombe and colleagues do not consider their study to be an experiment. The authors acknowledge limitations in their study (as there always are in any study) including that "the sample was limited to two schools and two science education specialists as instructors; the results should therefore not be generalized" (p.9).

Yet, of course, if the results cannot be generalised beyond these four classes in two schools, this undermines the usefulness of the study (and the grounds for the recommendations the authors make for teaching based on their findings in the specific research contexts).

If considered as an experiment, the study suffers from other inherent limitations (Taber, 2019). There were likely novelty effects, and even though there was no explicit hypothesis, it is clear that the authors expected enquiry to be a productive approach, so expectancy effects may have been operating.

Analytical framework

In an experiment is it important to have an objective means to measure outcomes, and this should be determined before data are collected. (Read about 'Analysis' in research studies.). In this study methods used in previous published work were adopted, and the authors tell us that "A coding scheme was developed based on the findings of previous research…and used during the coding process in the current research" (p.6).

But they then go on to report,

"Learners' drawings during the pre-test and post-test, their notes during class activities and their responses during interviews were all analysed using the coding scheme developed. This study used a combination of deductive and inductive content analysis where new conceptions were allowed to emerge from the data in addition to the ones previously identified in the literature"
p.6

An emerging analytical frame is perfectly appropriate in 'discovery' research where a pre-determined conceptualisation of how data is to be understood is not employed. However in 'confirmatory' research, testing a specific idea, the analysis is operationalised prior to collecting data. The use of qualitative data does not exclude a hypothesis-testing, confirmatory study, as qualitative data can be analysed quantitatively (as is done in this study), but using codes that link back to a hypothesis being tested, rather than emergent codes. (Read about 'Approaches to qualitative data analysis'.)

Much of Mamombe and colleagues' description of their work aligns with an exploratory discovery approach to enquiry, yet the gist of the study is to compare student representations in relation to a model of correct/acceptable or alternative conceptions to test the relative effectiveness of two pedagogic treatments (i.e., an experiment). That is a 'nomothetic' approach that assumed standard categories of response.

Overall, the author's account of how they collected and analysed data seem to suggest a hybrid approach, with elements of both a confirmatory approach (suitable for an experiment) and elements of a discovery approach (more suitable for case study). It might seem this is a kind of mixed methods study with both confirmatory/nomothetic and discovery/idiographic aspects – responding to two different types of research question the same study.

Yet there do not actually seem (**) to be two complementary strands to the research (one exploring the richness of student's ideas, the other comparing variables – i.e., type of teaching versus degree of learning), but rather an attempt to hybridise distinct approaches based on incongruent fundamental (paradigmatic) assumptions about research. (** Having explicit research questions stated in the paper could have clarified this issue for a reader.)

So, do we have a case study?

Mamombe and colleagues may have chosen to frame their study as a kind of case study because of the issues raised above in regard to considering it an experiment. However, it is hard to see how it qualifies as case study (even if the editor and peer reviewers of the EURASIA Journal of Mathematics, Science and Technology Education presumably felt this description was appropriate).

Mamombe and colleagues do use multiple data sources, which is a common feature of case study. However, in other ways the study does not meet the usual criteria for case study. (Read more about 'Case study'.)

For one thing, case study is naturalistic. The method is used to study a complex phenomena (e.g., a teacher teaching a class) that is embedded in a wider context (e.g., a particular school, timetable, cultural context, etc.) such that it cannot be excised for clinical examination (e.g., moving the lesson to a university campus for easy observation) without changing it. Here, there was an intervention, imposed from the outside, with external agents acting as the class teachers.

Even more fundamentally – what is the 'case'?

A case has to have a recognisable ('natural') boundary, albeit one that has some permeability in relation to its context. A classroom, class, year group, teacher, school, school district, etcetera, can be the subject of a case study. Two different classes in one school, combined with two other classes from another school, does not seem to make a bounded case.

In case study, the case has to be defined (not so in this study); and it should be clear it is a naturally occurring unit (not so here); and the case report should provide 'thick description' (not provided here) of the case in its context. Mamombe and colleagues' study is simply not a case study as usually understood: not a "qualitative pre-test/post-test case study design" or any other kind of case study.

That kind of mislabelling does not in itself does not invalidate research – but may indicate some confusion in the basic paradigmatic underpinnings of a study. That seems to be the case [sic] here, as suggested above.

Suitability of the comparison condition: lecturing

A final issue of note about the methodology in this study is the nature of one of the two conditions used as a pedagogic treatment. In a true experiment, this condition (against which the enquiry condition was contrasted) would be referred to as the control condition. In a quasi-experiment (where randomisation of participants to conditions is not carried out) this would usually be referred to as the comparison condition.

At one point Mamombe and colleagues refer to this pedagogic treatment as 'direct instruction' (p.3), although this term has become ambiguous as it has been shown to mean quite different things to different authors. This is also referred to in the paper as the lecture condition.

Is the comparison condition ethical?

Parental consent was given for students contributing data for analysis in the study, but parents would likely trust the professional judgement of the researchers to ensure their children were taught appropriately. Readers are informed that "the learners whose parents had not given consent also participated in all the activities together with the rest of the class" (p.3) so it seems some children in the lecture treatment were subject to the inferior teaching approach despite this lack of consent, as they were studying "a prescribed topic in the syllabus of the learners" (p.3).

I have been very critical of a certain kind of 'rhetorical' research (Taber, 2019) report which

begins by extolling the virtues of some kind of active / learner-centred / progressive / constructivist pedagogy; explaining why it would be expected to provide effective teaching; and citing numerous studies that show its proven superiority across diverse teaching contexts;
then compares this with passive modes of learning, based on the teacher talking and giving students notes to copy, which is often characterised as 'traditional' but is said to be ineffective in supporting student learning;
then describes how authors set up an experiment to test the (superior) pedagogy in some specific context, using as a comparison condition the very passive learning approach they have already criticised as being ineffective as supporting learning.

My argument is that such research is unethical

It is not genuine science as the researchers are not testing a genuine hypothesis, but rather looking to demonstrate something they are already convinced of (which does not mean they could not be wrong, but in research we are trying to develop new knowledge).
It is not a proper test of the effectiveness of the progressive pedagogy as it is being compared against a teaching approach the authors have already established is sub-standard.

Most critically, young people are subjected to teaching that the researchers already believe they know will disadvantage them, just for the sake of their 'research', to generate data for reporting in a research journal. Sadly, such rhetorical studies are still often accepted for publication despite their methodological weaknesses and ethical flaws.

I am not suggesting that Mamombe, Mathabathe and Gaigher have carried out such a rhetorical study (i.e., one that poses a pseudo-question where from the outset only one outcome is considered feasible). They do not make strong criticisms of the lecturing approach, and even note that it produces some learning in their study:

"Similar to the inquiry group, the drawings of the learners were also clearer and easier to classify after teaching"
"although the inquiry method was more effective than the lecture method in eliciting improved particulate conception and reducing continuous conception, there was also improvement in the lecture group"
p.9, p.10

I have no experience of the South African education context, so I do not know what is typical pedagogy in primary schools there, nor the range of teaching approaches that grade 4 students there might normally experience (in the absence of external interventions such as reported in this study).

It is for the "two experienced teachers who are university lecturers and well experienced in teacher education" (p.3) to have judged whether a lecture approach based on teacher telling, children making notes and copying drawings, but with no student activities, can be considered an effective way of teaching 8-9 year old children a highly counter-intuitive, abstract, science topic. If they consider this good teaching practice (i.e., if it is the kind of approach they would recommend in their teacher education roles) then it is quite reasonable for them to have employed this comparison condition.

However, if these experienced teachers and teacher educators, and the researchers designing the study, considered that this was poor pedagogy, then there is a real question for them to address as to why they thought it was appropriate to implement it, rather than compare the enquiry condition with an alternative teaching approach that they would have expected to be effective.

Sources cited:

Mamombe, C., Mathabathe, K. C., & Gaigher, E. (2020). The influence of an inquiry-based approach on grade four learners' understanding of the particulate nature of matter in the gaseous phase: a case study. EURASIA Journal of Mathematics, Science and Technology Education, 16(1), 1-11. doi:10.29333/ejmste/110391
Taber, K. S. (2013). Modelling Learners and Learning in Science Education: Developing representations of concepts, conceptual structure and conceptual change to inform teaching and research. Dordrecht: Springer.
Taber, K. S. (2019). Experimental research into teaching innovations: responding to methodological and ethical challenges. Studies in Science Education, 55(1), 69-119. doi:10.1080/03057267.2019.1658058

* Material reproduced from Mamombe, Mathabathe & Gaigher, 2020 is © 2020 licensee Modestum Ltd., UK. That article is an open access article distributed under the terms and conditions of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) [This post, excepting that material, is © 2020, Keith S. Taber.]

An introduction to research in education:

Taber, K. S. (2013). Classroom-based Research and Evidence-based Practice: An introduction (2nd ed.). London: Sage.

Can small-scale experimental investigations of teaching carried-out in a couple of arbitrary classrooms really tells us anything about how to teach well?

My creed…researchers should prefer to undertake competent work

A guide to using experiments to inform education

Scale of studies

Focus of study

Generalisation

Large-scale research to learn about the general case

Large-scale research to learn about the range of effectiveness

Small-scale research to incrementally extend the range of effectiveness

Small-scale research to inform local practice

Source cited:

Notes:

Someone else's research, that is

Research ethics

Pretending to operate on ill patients

Fair testing

Do no harm

Could this really ever have been considered ethical?

But do not believe everything you read…

Getting consent for sham surgery

Coda – what did the middle man have to say?

Work cited:

Note:

…if you believe that "knowledge is constructed in the minds of students"?

An imaginary conversation 1 with a team of science education researchers.

Constructivism

'Traditional' teaching versus 'constructivist' teaching

What is already known about SWH pedagogy?

What was the point of another experimental test of SWH?

What happened in the experimental condition?

What happened in the control condition?

The teacher variable

Was this research ethical?

A rhetorical experiment?

A technical question

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Notes:

When 'direct instruction' just becomes poor instruction

Rhetorical studies?

Problem-Based Learning in a 9th Grade Chemistry Class

Why is this rhetorical research?

Unethical research?

Isn't this 'direct instruction'?

Ethical review

PbBL is better than…deliberately teaching in a way designed to limit learning

Work cited:

Note:

Another ethically questionable science education experiment?

Jigsaw cooperative learning in elementary science: physical and chemical changes

Random assignment

Initial equivalence between groups

Comparing two conditions

The experimental condition

What is being compared?

A different curriculum?

The control condition

The teacher variable

And what do participants expect will happen?

A suitable teacher

Unethical, but not unusual

The problem of generalisation

An ethical alternative

Work cited:

Note:

When is "a case study" not a case study? Perhaps when it is (nearly) an experiment?

Key features:

Learners' conceptions of the particulate nature of matter

What kind of research design is this?

A teaching model of the states of matter

External teachers taught the classes

An experiment; or a case study?

The outcome

Representativeness

Analytical framework

So, do we have a case study?

Even more fundamentally – what is the 'case'?

Suitability of the comparison condition: lecturing

Is the comparison condition ethical?

Sources cited:

An imaginary conversation ¹ with a team of science education researchers.