THE scientific method; or scientific methods?
A topic in teaching science
An authentic science education asks learners to both learn about some specific scientific ideas and also to learn something of the nature of science – the practices of scientists and the processes by which new scientific knowledge is constructed and developed. There are a number of nature of science (sometimes abbreviated to 'NOS') themes that might be thought important to teach young people about.
(Read more about teaching the nature of science)
The scientific method
It has been suggested that the phrase 'the scientific method' is misleading as there is not a single scientific method: "One well known philosopher of science, Paul Feyerabend… argued that there is no such thing as the scientific method, but rather than scientists have to develop their own customised methods that will work in their own areas of research" (Taber, 2017, p.29).
Method, methodology, or technique?
Perhaps one issue here is what is meant by a method – as this can be taken as a rather particular, prescribed way of doing things. In social science research it is common to distinguish between methodology, which is an overarching research strategy (such as an experiment) and the more specific research techniques (or methods) used to collect and analyse data.
(Read about research methodologies)
(Read about research techniques)
Arguably rather than referring to 'the scientific method', it makes more sense to talk about a scientific attitude, or a scientific perspective, as what is common to the natural sciences (biology, chemistry, physics, geology, astronomy, biochemistry, paleontology, and so forth) is not a single methodology but an approach to framing questions, designing studies, handling data, and so forth.
Not all science is experimental
"A simplistic account of science has scientists testing their ideas by doing experiments that will prove or falsify their ideas. An experiment ideally explores a phenomenon under laboratory conditions, where variables of interest can be manipulated and measured and the potential effects of confounding variables controlled by keeping values constant. This is a problematic simplification in at least two regards. For one thing, not all scientists do experiments as such. In some branches of science it may be impractical or unethical to undertake experiments. It is not possible to manipulate the conditions at the centre of stars, or compare how life develops on a planet under different starting conditions. It is not generally considered acceptable to subject people to potentially dangerous conditions to see how their physiology reacts (although such research has been undertaken in the past). So, often scientists working in some scientific disciplines use observational approaches, looking for 'natural experiments' where features of interest naturally vary and allow conditions to be compared. Scientists also use simulations and models to test their ideas, being aware that the results are only as good as the (inherently uncertain and limited) simulation or model." (Taber, 2017, p.29)
(Read about experiment as a research methodology)
(Read about 'natural experiments')
Challenges to experimental work
"Even where genuine experiments are possible, the simple logic of 'proving' or refuting a hypothesis is over-simplistic.
- An experimental prediction may be correct for a reason other than the verisimilitude (closeness to the truth) of the hypothesis that led to its prediction.
- It is always possible to produce alternative theories to explain any set of data (even if sometimes the alternatives seem cumbersome and forced).
- Any experimental data set intended to test some general hypothesis is necessary sampling a very small proportion of the population of possibly relevant events. (Consider how you would test for certain that adding salt to water always lowered its melting temperature; or that the human heart always has four chambers; or that the electron always has a charge of 1.6×10-19C.)" (Taber, 2017, p.29)
| "…every scientific experiment involves two series of transformations and a comparison. | ||
| Nature is transformed to obtain special events, these events are further transformed by data processing devices, scanners, etc. to turn them into evidence | which is then compared with | the outcome of a transformation of high theory through calculations, computer approximations, phenomenology, etc." |
The problem of induction, the challenge of refutation
At one time, it was considered that (following a methodological approach suggested by Francis Bacon) making suffcient observations allowed one to infer the nature of things – a process known as induction.
Read about induction in enquiry
However, logically induction does not assure correct conclusions, resting on additional assumptions that are made,
"The question still recurs, on what process of argument this inference is founded? Where is the medium, the interposing ideas, which join propositions so very wide of each other?
David Hume, 1777
Interposing ideas might, for example, include assumptions about natural kinds -e.g., sodium chloride is a natural kind of stuff with its own set of properties, so if this sample of sodium chloride is soluble in water, other samples should also be soluble.
We also always assume, as Hume noted, "all reasonings from experience are founded on the supposition, that the course of nature with continue uniformly the same". This might be considered a metaphysical assumptoin which is necessary to do any science.
"The difficulty of proving general statements from a limited sample of instances (known as 'the problem of induction') led the famous philosopher of science Karl Popper to recommend that scientists focus more on refutations which at least seemed to rule out hypotheses where experiments did not agree with theoretical predictions… However, this is just as problematic. Experiments can go wrong for all kinds of reasons – impure chemicals, laboratory (e.g. technician) error, instrument error, faulty power supplies, unexpected and unnoticed temperature fluctuations, and so forth.
Moreover, most modern science uses complex apparatus of measurement and analysis that relies on its own theory of instrumentation. A hypothesis that is correct may seem to need to be rejected if the theory behind the instrumentation is flawed – so scientists need to be wary of too easily rejecting ideas as well as being careful about when considering them supported. Science is a more complex business that many school practical activities would suggest!" (Taber, 2017, p.29)
Experiments in the natural and social sciences
Despite these challenges, experiments are still a very important and common basis for scientific studies. When an experiment is possible it is often the most powerful methodology for answering research questions, even if we need to be aware interpreting results may not be straightforward, and experiments can not 'prove' our hypotheses.
When use properly the term proof refers to something that shows a claim is definitely true. In mathematics, it is possible to demonstrate things using logic because mathematical objects can be precisely defined. Science deals with empirical evidence about natural kinds (observed categories of things in nature – like samples of methane, blue whales, or volcanoes) and so only produced theoretical knowledge.
(Read about the nature of scientific knowledge)
If experiments in the natural sciences may be difficult to interpret, experiments used in social sciences (such as experiments to test different teaching approaches) present even greater challenges.
(Read about experimental research into teaching innovations)
Work cited:
- Feyerabend, P. (1999). Conquest of abundance. A tale of abstraction versus the richness of being. (B. Terpstra, Ed.). The University of Chicago Press.
- Hume, D. (1777/2007) An Enquiry Concerning Human Understanding. Edited and with an Introduction and Notes by Peter Millican. Oxford: Oxford University Press
- Taber, K. S. (2017). Reflecting the nature of science in science education. In K. S. Taber & B. Akpan (Eds.), Science Education: An International Course Companion (pp. 23-37). Rotterdam: Sense Publishers. [Download the chapter.]
