Manipulating and diversifying the levels of difficulty and task‐sophistication of one and the same laboratory exercise

Teaching in heterogeneous classes is often a perplexing enterprise for the teacher who must cope simultaneously with children of various abilities and motivations. The recommended strategies endeavour to adapt specific tasks to individual needs. However, experienced teachers, while never challenging the theoretical validity of such strategies, tend to question their practical feasibility. The activity presented here deals with the potential of laboratory‐based science teaching for mixed‐ability classes. It will show that even a relatively simple experiment may become a rich source of different tasks which can be adapted to the wishes of the teacher and the needs of the pupils. The factors which bear on the difficulty of these tasks can be defined. The difficulty of a laboratory activity will depend mainly on the cognitive level and the technical skills required and on the burden imposed on the pupils. The teacher may increase, reduce or rearrange the elements of difficulty all along the activity which can thus be performed simultaneously at various levels, by different pupils in the same class.