B1 Predict, observe, explain

Learning from the PEEL Experience, page 230
June 1995

This procedure has three stages. Firstly the students are shown a situation and asked to make a written prediction with reasons as to what they think will happen when some change is made. Crucial to the procedure is the discussion at this point of the various predictions and the reasons for them, it is, of course, essential that the teacher gives no indication of what he or she believes. Then the change is made and the students record their observation of what happened. Finally they attempt to make explanations to account for any differences between their prediction and their observations. As an example of this procedure, part way through reading a novel the teacher stopped the class and asked them to predict, with reasons, what they thought would happen next. When this was done, most students did not draw on strong indications that the author had already given about the hopelessness of the position of the main characters. Most students predicted a quite unrealistic happy ending. When they had finished the book they had to explain why the author had written an unhappy ending. This led to a deeper understanding of the characters and their motives.

POEs have been used a lot in Science. They provide an important way of tacking the poor learning tendencies of Non Retrieval and Ineffective Restructuring; the students predictions are based on the beliefs that they have brought into the classroom and sorting out why they predicted incorrectly can be very effective in restructuring these ideas. Students might be asked, for example to predict whether or not they think a ballon full of air will weigh more, less or the same as an empty balloon. Students thinking during many conventional practical activities can be improved by asking them to predict, and discuss what they expect will occur and why.  This focuses their thinking on the range of possible outcomes and the significance of each of these. POEs are diagnostic, they involve the whole class, they demonstrate to students that they do have views, and they stimulate students to find out, if their prediction was wrong, why it was wrong.  The centrality of the students ideas (rather than the teacher s) to the activity provides a good way of building a sense of shared intellectual control (PEEL Principle 1).  The discussion promotes tentative, exploratory talk (Principle 5) as well as encouraging students to listen and respond to other students ideas (Principle 6).

However, one problem with this approach is that students often are reticent about committing to a prediction and writing it down in fear of "writing the wrong thing" in their books. To avoid this, Misja Carbo and Penny Hondrakis (Using Logbooks in Year 10 Electricity) asked the students to make a special "logbook" out of the (recycled) paper and card they provided. Because the logbook was not their regular science book, students were more willing to commit their ideas and predictions to paper. First they asked the students to draw up a concept map using terms from the unit on static electricity that they had done in year 9. The Logbook helped here because it did not seem to matter as much to get "the right answer" on paper. They then proceeded, using a series of POE experiments to explore the nature of current electricity.

The students responded very well to this approach. "Can we please have Logbooks for every topic!" was one comment. When asked why, they liked it the answers varied from: " you look after them (the logbooks) so we can t lose our work" to "You can see how your ideas about electricity change."

There are a number of criteria for a good POE:

  1. The students must feel able to give a prediction - pure guessing is not at all useful. Using a familiar situation where the prediction involves a problem likely to be a real one to the students will assist in this process.
  2. The "O" of a POE should be clear. We have found a strong tendency by students to "observe" what they wanted to see. The result should be concrete.
  3. When POE s are being used to specifically challenge student views the result should be surprising - in direct conflict with that predicted by the common alternative views. However, POE s don t always have to "surprise". Using POE s only in circumstances when predictions do not match observations can firstly result in negative feelings towards the procedure and secondly lead to students picking the "unlikely" result because "we always predict wrongly". There are many occasions in Science subjects where predicting a change correctly can help build students confidence in their new understandings; sometimes this can occur as part of a series of related POEs, where the teacher expects many incorrect predictions early, but a shift to mainly correct predictions as students restructure their understandings.
  4. Students should be able to explain the result. There is no point in giving a Year 9 class a POE which requires Year 12 physics to explain.

The following points are advice drawn from experience.

  1. It is crucial that the students realise they are not alone in their predictions. This means it is important to summarise the class views and report these back to the class. An effective way of doing this is in written form where the teacher collates their results.
  2. It must be seen by the students as a non-threatening situation. Never give marks or even praise for "correct" answers. Stress to students that you only want their opinions, and predicting incorrectly can be at least as helpful as predicting correctly. If the class is unfamiliar with the procedure, it can help to collect the responses anonymously.
  3. Incorporating an interpretive discussion (B3) after the "P" and before the "O", where the competing positions are debated and clarified, is almost always important in helping students clarify, and sometimes change their ideas.
  4. At the end of the exercise ensure that the "incorrect" predictions are seen as often sensible and always helpful to the learning (by stimulating constructive debate).  This debrief helps build a classroom environment that supports the risky learning behaviours of offering and defending ideas and expressing disagreement (PEEL Principle 7).

Further activities can reinforce the correct predictions. Together with a P.O.E. on particle theory, Julie Morrow (Combining a role play and P.O.E.) found having students act out what was happening further reinforced understanding of the key concept.


Creating a situation which intrigues students to make and test a series of predictions which build on each other can lead to a classroom atmosphere that recognizes students ideas and lateral thinking . The improvement in student behaviour (as described by Ian Mitchell in The Floating Paper Clip) can be dramatic.