Semantic memory tasks can focus on intensions (features and properties) or extensions (reference and categorization). The two aspects, intension and extension, should in principle be closely related. It is in virtue of possessing the intensional properties of a concept that an individual entity will be included in the extension of that concept. For example, any feathered creature that hatches from eggs and has two legs and a beak will be a bird, and any creature lacking any of these features will be something else. There is evidence for stable individual differences in each of these tasks, but these differences do not correspond across tasks. Two further studies show that, under certain conditions, the correspondence can be demonstrated. This chapter discusses reasons for the lack of connection in terms of different systems for conceptual understanding involving similarity versus theory-based conceptualization.
Can children construct inverse relations in arithmetic? Evidence for individual differences in the development of conceptual understanding and computational skill
