Equivalence Classes: Effects of the Redundant Element and the Order of Tests

ABSTRACT It was investigated the effect of the order of testing on equivalence class formation and stimulus control after teaching simple discriminations that included a redundant element (black spot). Nineteen college students were exposed to conditional relations training, as also testing of equivalence classes and stimulus control with mask. The order of testing varied in two experimental phases: (1) tests alternated with training, and (2) tests after training. A black spot was included in one of the compound stimuli. More accurate performances occurred when tests were conducted after training. Higher scores were related to control by S + and the S- and lower scores to multiple controls that included the black spot. These results suggest that the order of testing interact with the effects of the redundant element.