Probability of Stimulus Equivalence as a Function of Class Size vs. Number of Classes

Abstract

Two experiments were conducted to study stimulus equivalence as a function of class size and number of classes. In the first experiment, equivalence was tested in 50 normal adult subjects following a linear series training structure. Subjects were successively assigned to either of 10 groups, exposed to a specific stimulus material. For subjects in which number of classes increased, up to six, B-stimuli served as pictures, while A-, and C-stimuli were Greek letters, and “equivalence” was tested in CA tests. The A-, B-, and C-stimuli were the same for ail subjects in whom class members increased up to six, where D-, E- and F-stimuli were Greek letters. Following AB, BC, CD, DE, and FE training, FA, EA, FB, FC, EB, DA, FD, EC, DB, and CA “equivalence” tests were run. In the second experiment, a many-to-one training structure was used to study equivalence as a function of increasing class size without increase number of nodes. The results indicate that the probability of equivalence decreased more as function the number of nodes than as a function of number of classes. Reaction times, particularly to the comparison stimuli, generally increased initially during tests, possibly indicating precurrent problem solving behavior prior to the response to a comparison stimulus.