Equivalence Outcome in Single Subjects as a Function of Training Structure

Abstract

Previous studies comparing groups of subjects have indicated differential probabilities of stimulus equivalence outcome as a function of training structure. Both one-to-many (OTM) and many-to-one (MTO) training structures seem to produce stimulus equivalence more often than a linear series training structure. The purpose of the present study was to explore whether or not corresponding differential probabilities of equivalence outcome as a function of training structure can be demonstrated in the performances of single subjects. In Experiment 1, equivalence outcome was tested successively following training according to each of the three training structures. All subjects responded in accord with equivalence following the OTM training structure independent of the training order, except for 1 subject who did not respond in accord with equivalence following neither of the three training structures. Furthermore, 2 subjects demonstrated individual success following both one-to-many and many-to-one training even when they did not demonstrate success following linear series training, while the reverse never happened. In Experiment 2, equivalence outcome was tested successively following training according to a many-to-one and a one-to-many training structure with both 2 and 3 classes of stimuli. The results showed that all subjects responded in accord with equivalence following the OTM training structure, while 2 subjects did not respond in accord with equivalence following the MTO training structure. In Experiment 3, equivalence outcome was tested successively following training according to a many-to-one training structure and one-to-many training structure with both 3 and 4 members in each class. In accord with the results of Arntzen and Holth (1997) the present results indicated a superiority of the one-to-many over alternative training structures as regards the probability of an equivalence outcome. There was no difference in the probability of an equivalence outcome following one-to-many and many-to-one as a function of increasing number of members. The difference in number of comparisons connected to each sample as a consequence of the dissimilarity in the training structures is discussed as a possible explanation for the difference in equivalence outcome.