Prompt-aided instruction of mirror-image discriminations: Abrupt prompt removal,time delay,and self-evaluation

This study compared three types of prompt-elimination procedures for helping children respond to left-right mirror-image stimuli. Three populations participated: normally developing preschoolers, students with mild mental retardation, and students with moderate mental retardation. All subjects were first trained to discriminate the stimuli in the presence of multiple pictorial prompts. These prompts required the subjects to discriminate the compounds on the basis of orientation. Then the prompts were eliminated, abruptly, with a time-delay procedure, or with a procedure requiring subjects to use the prompts to self-evaluate the accuracy of their responses. The results showed the following. First, most subjects rapidly discriminated the compound stimuli. Second, about 50% of the subjects of each population discriminated the task stimuli even when the prompts were abruptly removed. Time delay was highly effective with the normally developing preschoolers and students with mild mental retardation, but not with students with moderate mental retardation. The self-evaluation procedure was effective with all three populations.