Association for Behavior Analysis International

Stimulus equivalence is the behavioral analogue of concept formation. To form classes of equivalent stimuli training of discriminations occurs in a specific sequence that results in the emergence of novel (untrained) relations between stimuli. These stimuli become mutually substitutable and interchangeable for one another. Although the procedures for creating such classes has been available since 1971 and an extensive, reliable, and efficacious history exists, the use of this technology for the instruction of children with autism spectrum disorders (ASD) is limited. This symposium presents3 studies in which children with ASD (or their parents) formed equivalence classes involving synonyms (Macauley, et al.), behavior analytic interventions (Persson and Maguire) and science concepts (Leonard et al.) , errorlessly and consistent with the general curriculum. Additionally, all instruction was conducted within typical settings, using standard technologies (e.g., a laptop computer and PowerPoint software). The results are discussed in term of increasing the efficiency with which children with ASD (and their parents) are taught advanced and complex concepts.

Matching-to-sample procedures were used to establish equivalence relations with names, definitions, and description of applications of schedules of reinforcement including differential reinforcement of alternative behavior (DRA), Differential reinforcement of other behavior (DRO), and noncontingent reinforcement (NCR). These procedures were presented in a multiple-choice paper and pencil procedure and used with parents of children with diagnosed mental illness and developmental disabilities. A to B relations were trained to include reinforcement schedule name as a sample and definition as comparison, followed by A to C relations with name as sample and description of application as comparison. Following training, all emergent relations including symmetry and transitivity were tested in extinction as well as testing of emergent naming relations of video representation of application of reinforcement schedule. A comparison was then made between2 groups,1 with the matching-to-sample procedure and1 with a traditional modeling procedure. Data were compared to determine the rate of decrease in physical aggression of the children of the parents involved in the study to those who were not.

Vocabulary development is a challenging skill to acquire. The use of stimulus equivalence in creating classes of stimuli has been well documented in both experimental and applied settings (Sidman, 1994). Equivalence can be defined as the emergence of untrained and nonreinforced stimulus-stimulus relations following the training and reinforcement of some stimulus-stimulus relations. In this study,2 participants were trained to develop classes of synonymous vocabulary words. Following pre-testing on all possible relations, students were trained to match2 stimulus-stimulus relations using a computer based interactive PowerPoint. Training consisted of an errorless learning procedure where the incorrect comparison stimuli were faded from the screen leaving only the correct comparison stimulus. Following training, students were assessed for the emergence of the symmetrical and transitive relations and ultimately class formation. Results for each participant indicated that they developed3 3-member classes of synonymous words with some variability. This procedure was then successfully replicated using a novel series of vocabulary words with both participants. These results indicate that stimulus equivalence training in the classroom setting has the potential to be an efficient and productive methodology for the delivery of vocabulary instruction.

A student with an autism spectrum disorder was taught the science concepts of carnivore, herbivore, and omnivore using stimulus equivalence technology and errorless instruction. Initially, he was taught to match the picture of a skull and a written definition to the printed words carnivore, herbivore, and omnivore. Following this training the student was then able to reverse the previously taught skills (match the printed word to the related skull and definition) and match the definitions to the skulls (and vice versa) all without additional training or reinforcement. As a result, the student formed 3, 3-member concepts of carnivore, herbivore, and omnivore. Although only2 relations were directly trained the student was ultimately able to match each stimulus in a class to every other member of that class, for a total of 12 emergent and untrained relations. Interestingly, the time it took for this student to form these classes was substantially less than general science curriculum, which failed to teach him these concepts.