Response variation and the generalization of a dressing skill: comparison of single instance and general case instruction.

Two, identical multiple-baseline-across-subjects designs were used to compare the effects of single instance and general case instruction on the generalized dressing of youth and adults with severe mental retardation. Performance across eight nontrained, probe shirts was used to assess generalization of the skill "putting on pullover shirts." Following training with a single shirt, subjects exhibited limited success with the eight nontrained shirts. Only after training with a set of shirts that sampled the range of stimulus and response variation for "putting on pullover shirts" was successful generalization observed. Results suggest that the response variations taught during general case instruction played a major role in improved performance across the nontrained shirts. Implications of the results are discussed for instruction in applied settings, and for research methodology in the analysis of generalization.