Highlighting the role of the episodic situation model in the solving of arithmetical problems

The objective of this research was to compare two types of models used in problem solving: those which give priority to intermediate qualitative representations, such as the episodic situation model, and those which are centred on the activity of the participant and are of a procedural nature. Two-step distributive problems were chosen that could be solved using two different strategies: factorisation or development. These problems were given to French primary school pupils in year groups 3rd grade (8–9 years old) and 5th grade (10–11 years old). Each problem was formulated in four different ways by crossing two variables which modify the text: on the one hand, the presence of an element structuring the objects enumerated in the problem and on the other hand, the order of the numerical data. We have noted the percentage of ‘factorisation’ strategies used by the pupils. The results show that (1) factorisation was most often used by the older pupils; (2) the presence of a structuring element increased the number of factorisations whereas the order of the numerical data had no effect. This suggests that the problem-solving models which involve the episodic situation model are more suited to result interpretation than procedural models.