The original purpose of this study was to determine if Tegretol has an effect on the impulsive behavior exhibited by people with mental retardation. This was to be accomplished through a replication of the self-control choice procedures used by Ragotzy, Blakely, and Poling (1988). The procedure involved three stages. First, subjects chose between stimuli that provided either one or three edibles. Then the stimuli associated with the smaller and larger edibles were reversed. Following this, the procedure required the implementation of successively longer delays to the larger reinforcer. However, none of the subjects who participated was able to make the discriminations necessary to proceed, i.e., the subjects did not systematically select the stimulus associated with the larger magnitude edible choice. The identification and rectification of these errors in discrimination became the focus of this study. Various procedures were used to enhance discrimination, including fading, adjusting the magnitude of the edibles, and stimulus changes. None of these changes was successful in teaching the subjects the necessary discriminations.