Classificatory Schemes in Relation to Class Inclusion Before and After Training

Data are presented which elucidate Piaget’s contention that learning, measured by training effects, and development, measured by available schemes, are interacting factors with the latter determining the former. Classificatory schemes were assessed on independent tasks and then class inclusion performance was observed before and after training. Schemes pertinent to class inclusion were related to modes of pretest failure and on the post-test they differentiated successful from unsuccessful subjects. These results support the view that operatory class inclusion requires coordination between logical intension and extension, a process which can be facilitated through training.