RESUMO
The present study evaluated the effectiveness of using positive practice overcorrection in combination with other techniques to teach two manual signs ("milk" and "cookie") to an autistic boy. This boy had a great deal of difficulty in forming any type of discrimination and often became confused in learning the most simple simultaneous discrimination. Intervention primarily consisted of positive practice overcorrection in which the subject was physically guided to form a required hand sign 10 times when he responded incorrectly and was positively reinforced when he signed correctly. The study used a changing criterion within a multiple-baseline design across responses. The results indicated that overcorrection plus positive reinforcement was effective in teaching one sign (milk), however, and added contingent exercise (having to stand up and sit down 10 times for an incorrect response) was required to teach the second sign (cookie). Once the two signs were learned to a criterion level, it was a relatively easy task for the subject to respond correctly with the signs in a matching-to-sample task.
