Assistance Procedures to Facilitate the Transfer of Stimulus Control: Review and Analysis

Teachers of moderately to severely developmentally disabled students typically employ some form of assistance procedure in order to facilitate and/or prompt correct responding. Assistance may take the form of verbal, model, or physical prompts. In any form, these additions to the natural cue must eventually be removed or faded to ensure independent performance in the presence of naturally occurring stimuli. The systems of stimulus fading (e.g., Sidman & Stoddard, 1967), stimulus shaping (e.g., Schilmoeller, Schilmoeller, Etzel, & Le Blanc, 1977), increasing assistance (e.g., Gaul, Nietupski, & Certo, 1985), decreasing assistance (e.g., Oliver & Halle, 1982), graduated guidance (e.g., Azrin & Armstrong, 1973), and time delay (e.g., Snell, 1982) incorporate fading strategies to transfer control from the prompt to the naturally occurring stimulus. While many research accounts attest to the efficacy of discrete systems (e.g., Foxx & Azrin, 1973; Freagon & Rotatori, 1982; Giangreco, 1983; Halle, Marshall, & Spradlin, 1979; Horner & Keilitz, 1975; Johnson & Cuvo, 1981; Touchette, 1971), few investigations validate integrated procedures (e.g., Mosk and Bucher, 1984) or compare assistance systems (e.g., Gentry, Day, & Nakao, 1979) to identify the most salient teaching strategies. This article reviews and analyzes existing assistance procedures, and offers suggestions for the selection and integration of these procedures.