A topic in teaching science
Predict-Observe-Explain, P-O-E, is a technique that can be used to support learning about topics areas where students are likely to have strong intuitions which do not match scientific accounts of the world.
It can be seen as part of 'constructivist' pedagogy as it is a teaching technique which acknowledges the importance of students' existing thinking in influencing their learning.
Read about constructivist pedagogy
The teaching approach
As the name suggests, the approach uses a three-stage activity, where the students are asked to first, predict, then observe, and then explain.
Predict
The first stage is about eliciting student's thinking about a topic. This is especially important in topics where research has already told us that many learners will come to class with strong intuitions about phenomena which are contrary to what actually happens. (It is know than in such cases what students observe and are told may soon be forgotten or confused with their pre-exisitng thinking.
Even when this may not be the case, making a prediction will give students some sense of ownership in the following activity – a stake in the outcome as it were. Very often what children learn in science are answers to question they had never posed in the first place! (Who cares if the angle of refraction is different to the angle of incidence, or if the woodlouse prefers the damp?)
One way of motivating science learning is through offering epistemic relevance, where: "students should learn conceptual and theoretical content in the context of appreciating the chemical questions that motivated it" (Taber, 2015), so undertaking a prediction gives learners ownership of the question being asked when making the observation.
An example
An example, consider the question – what will happen to the magnitude and period of the swing of a pendulum over time?
Most learners will expect the extent of the swing (the displacement form the vertical) to reduce over time. But what about the period:
- will swings take longer as the pendulum is 'slowing down'?
- will swings take less time as the bob has less far to swing in each cycle?
- will the timing of a swing stay much the same as the amplitude decays?
A science teacher probably knows the answer – but what will most learners expect? Perhaps in many classes there will be different intuiti0ns about this?
Observe
Only once the learners have predicted what will happen, do they make their observations.
As the technique is most useful when learners are likely to find an observation counter-intuitive, it will often be that what is is observed does not tally with expectations. Having made a prediction should make this more salient, as well as motivating the question of why the unexpected happened.
Explain
Providing an explanation is especially important when the observation was contrary to the students observations – leading perhaps to 'cognitive dissonance'.
Clearly the objective here is not just for learners to form explanations (although developing explanations is an important scientific practice that probably does not get enough attention in school science), but for the learners to acquire a scientifically acceptable explanations (at the appropriate curriculum level).
So, although P-O-E can be en as a student-centred learning activity, the teacher will be actively engaging with learners during the activity, seeking to channel their thinking in the desired direction.
(Some people think that constructivist teaching is meant to be about valuing students ideas for their own sake, a kind of conceptual anarchy, but he main reason constructivist teaching puts such focus on students' ideas is because research shows that these direct school learning and needs to be engaged with and often challenged to shift student thinking towards scientific accounts.)
A dialogic activity
Although P-O-E can be undertaken by individual learners, it often works best in group settings, where small groups discuss their ideas. This tends to elicit a range of ideas hat can be compared rather than one idea, and where there are different ideas students have to put effort into explaining and justifying their ideas against challenges.
Of course for such groups work to be productive, the students need to have the skills of effective listening, turn taking, and argumentation – skills that normally need to be developed over time with help from the teacher.
Work cited:
- Taber, K. S. (2015). Epistemic relevance and learning chemistry in an academic context. In I. Eilks & A. Hofstein (Eds.), Relevant Chemistry Education: From Theory to Practice (pp. 79-100). Sense Publishers.
The topic will be treated in more detail in a book being prepared for the RSC Advances in Chemistry Education series.
