STIMULUS EQUIVALENCE CLASS FORMATION AND EXPANSION VIA OBSERVATIONAL LEARNING

Abstract

This study investigated conditional discrimination acquisition, stimulus class formation and stimulus class expansion through a modeling procedure. Six college students were taught conditional discriminations with five stimulus sets. Stimuli were black line drawings of common objects against white backgrounds. BA relations were taught individually, in a manner similar to that typically described by the literature, without modeling, followed by the teaching of CA relations, taught through a modeling procedure. During the teaching of BA relations, correct and incorrect comparison selections were followed by differential reinforcement. During CA, subsequent DA relations and EA relations training, subjects were instructed to observe a model that actually made the selections and received differential reinforcement for that. After the teaching of BA and CA relations, symmetry, transitivity and equivalence tests were introduced, followed by DA and EA teaching and tests for equivalence class expansion. All participants showed equivalence class formation and all but one participant showed expanded classes to include stimulus sets D and E into the previously formed class. Whether the observed results were an exclusive function of modeling or a combination of modeling and sequential effects of the directing teaching of BA requires further investigation. Key words: modeling, stimulus equivalence, conditional discriminations, observational learning