A comparison of time delay and system of least prompts in teaching object identification.

This study is a comparison of two response prompting procedures: Progressive time delay and system of least prompts. Three students with severe handicaps were each taught to identify eight functional objects, four objects with each prompting procedure. The procedures were compared in terms of effectiveness (establishing criterion level correct responding) and efficiency, (sessions and trials to criterion, errors to criterion, and the number of minutes of direct instructional time). A combination of two concurrently operating multiple probe designs (Parallel Treatments Design) in which extraneous variables were counterbalanced across sessions was employed. An analysis of the results indicates that both prompting procedures were effective in establishing correct responding at criterion levels, but the time delay procedure required fewer sessions, trials, and errors to criterion, and fewer minutes of direct instruction time than did the system of least prompts. Issues for further comparative research are discussed.