Lesson 18 Prediction and correlation
Episode 2
Reasoning | Resources: Worksheet 2 on OHT |
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Whole class introduction | |
Piaget described qualitative understanding of correlation as early formal, and a quantitative treatment (because it involves proportion) as mature formal, since it is one of the ways in which people proceed from possible models to seeing whether reality agrees with the model. Only about 20% of pupils by the end of Year 8 (without intervention) have access to early formal thinking (or above), so the teaching of correlation as a purely instructional aim is inappropriate for at least 70% of pupils of this age. | ![]() Ask: How many got E grade in science? How many got grade E in maths? Draw a faint, narrow lasso to show the range in each case. |
Pair work | |
However, the majority of 12 year olds recognise intuitively that scatter diagrams show relationships. Many can also estimate the strength of relationship by how close the scatter is to being a simple straight line. | This episode can be carried out as whole class with pupils given short periods to work in pairs on one question at a time, with immediate feedback. Questions for paired work:
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Here we are dealing with descriptive models (concrete operations) where there is a direct relation between the form of a graph and the relation it is modelling. | ![]() |
End of Lesson Reflection | |
What do you think are the advantages and disadvantages of this kind of mathematics - the mathematics of correlation? Elicit the ideas that correlation allows us to make predictions, or rather shows us likely limits for a prediction, and that the predictions are not precise. Ask for the differences between this and the work in Episode 1. | |