Concept Learning as a Function of Form of Internal Structure

Garner (1962) distinguished between internal structure as the relations between variables making up a specified set of stimuli, and external structure as the relations between the stimuli and some external variable such as a differential response. He also argued that factors involved in external structure are most closely related to psychological processes of discrimination, or learning tasks such as paired associates which involve learning a differential response to each stimulus. Internal structure, on the other hand, is most closely related to free-recall learning. Whitman and Garner (1962), for example, have shown that the form of internal structure has a very great effect on free-recall learning of visual figures; specifically, that form of internal structure which involves simple contingencies between pairs of var~iables defining the stimuli facilitates free-recall learning. Concept learning involves both internal and external structure, since S in such an experiment is required to learn which stimuli belong in a specified subset of the total number of possible stimuli, but is also required to