Systematic correction procedures in vocational-skill training of severely retarded individuals

Seventy severely retarded adults were taught a vocational assembly-skill task involving a difficult visual--motor discrimination. Comparisons of relative effects on trials-to-criterion were made among two types of verbal-correction procedures (general: "try another way" and specific: "flat side in") and three types of systematic physical-correction procedures (gesture, physical prompt, and repeated practice). Reliable differences in effects occurred only between the three systematic physical-correction procedures, with repeated practice the most effective, physical prompts next, and gestures the least effective. The results were interpreted as demonstrating the efficacy of trainer-related training procedures in relation to stimulus-related strategies, as well as relative efficacy among trainer-related correction procedures.