An analysis of the effects of contingent delivery of tasks with different difficulty and noncontingent delivery of tasks with different preference

This investigation examined instructional strategies derived from the Premack principle and task interspersal strategies for four students with moderate to severe developmental disabilities. In both studies, baseline consisted of massed instruction of thirty trials. During study one, students were given contingent access to preferred easy tasks for correct responding in one condition. In the second condition, students were given contingent access to preferred difficult tasks for correct responding. During study two, students were given noncontingent access to preferred easy tasks for correct responding in one condition. In the second condition, students were given noncontingent access to nonpreferred easy tasks for correct responding. A reversal design was used to evaluate the results. Tasks were identified using a task preference assessment based on the free operant preference assessment. For study one, results indicated that four out of four participants had higher response accuracy when preferred easy tasks were presented contingently. Four out of four participants had lower response accuracy when given contingent access to preferred difficult tasks when compared to the contingent preferred easy task condition. For study two, results indicated that four out of four participants had higher response accuracy when preferred easy tasks were presented noncontingently. Three out of four participants had levels of response accuracy equal to or lower than baseline when nonpreferred easy tasks were presented noncontingently