The effects of long and short durations of positive practice overcorrection were studied, for reduction of off‐task behavior after an instruction to perform an object‐placement task. Off‐task behavior, correct responses, and approximate responses were all observed. Off‐task behavior received positive practice. The short and long practice durations (30 seconds and 3 minutes) produced equally rapid reduction of off‐task behavior and acquisition of correct object‐placement performance. Over sessions, much less time was required for positive practice when the short practice duration was used. Approximate responses, which also avoided positive practice, occurred at low rates relative to correct responding. Negative side effects were observed to occur primarily during sessions with long positive practice. These results indicate that use of short durations of positive practice can reduce the practice time required and negative side effects, with no loss of training effectiveness either for reducing inappropriate behavior or increasing a desired alternati