A model for processes of abstraction, based on epistemic actions, has been proposed elsewhere. Here we apply this model to processes in which groups of individual students construct shared knowledge and consolidate it. The data emphasizes the interactive flow of knowledge from one student to the others in the group, until they reach a shared…

Reports results of a study of biology classes in Israel that includes describing transactions in a representative sample of biology classes (N=22) in the year 1973, comparing transactions in recitation with those of laboratory lessons, and studying the effects of subject matter on the classroom transaction. (CS)