Two children with autism were assessed for preference between intersession distribution of mastered and unknown instructional trials on a computerized matching-to-sample task consisting of 12 total learning opportunities. Choice responses yielded presentation of either massed-trial sequencing (six unknown/six mastered stimuli relations or vice-versa) or alternating-trial sequencing delivery (alternation of unknown and mastered stimuli relations) followed by reinforcement for correct responses. An extinction condition served as an experimental control. Both children demonstrated a preference for the alternating-trial sequencing condition, and implications for instructional programming and possible effects to delays to higher rates of reinforcement are discussed.
