Stimulus Arrangement in Simple Discriminative Training with Compound and Emergence of Stimulus Equivalence Classes

Simple simultaneous discrimination training (SSD) with compound stimuli has produced variability in results of stimulus equivalence tests. This paper presents two studies investigating the role of methodological variables that alter the chance of control by aspects not defi ned as relevant for the formation of stimulus equivalence classes. Study 1 evaluated the effect of using an incorrect compound (S-) for each correct compound (S+) in each SSD trial that granted the conditional discrimination context without redundancy (e.g., A1B1 with A1B2 or A1B1 with A2B1). Five undergraduate students learned basic discriminations and showed symmetrical and transitive relations. The second study assessed the effect of a redundant element (a black spot) included on compounds of one of the classes in a training procedure of arbitrary conditional relations with SSD. The effects of this manipulation were investigated on performance of emergent relation tests, using MTS and SSD. All twelve students showed symmetrical relations, but only fi ve showed transitive relations. These results expand the evidence that the confi guration of training trials and irrelevant characteristics of stimuli may generate false positives in discriminative training.