Teaching Stimulus Classes to Encourage Independent Purchasing by Students with Severe Behavior Disorders

Abstract

The purpose of this study was to evaluate a method to teach purchasing to three students with developmental disabilities and severe behavior disorders who had minimal academic skills. To bypass the need for money computation skills, the students were taught to discriminate between three stimulus classes of frequent purchases (vending machine snack, convenience store snack, lunch). To teach the stimulus classes, multiple exemplars of each class were utilized with time delay of a response prompt and a stimulus prompt (money picture) to facilitate correct responding. Visual referents (pictures of the items to be purchased) were presented in a massed trial teaching format. Over subsequent phases the discrimination was made more difficult by dropping the money picture prompt and then withdrawing all visual referents and shifting to distributed trial instruction. Two of the participants mastered the stimulus classes and generalized these discriminations to making community purchases. The third made important gains in both acquisition and generalization of the responses before the program ended for summer vacation. The results are discussed for their implications in teaching purchasing skills to individuals who do not have typical academic prerequisites.