Fig. 5

Three examples of physics problems that would be categorized differently by novices and experts. The problems in (a) and (c) look similar on the surface, so novices would group them together into one category. Experts, however, will recognize that the problems in (b) and (c) both relate to the principle of energy conservation, and so will group those two problems into one category instead. Copyright note: the figure was produced by the authors, based on figures in Chi et al. (1981)