Duration-based measures of preference for vocational tasks.

We compared results from two preference assessments with data on extended performance of vocational tasks by 4 participants with developmental disabilities. All participants engaged in one task exclusively when seven tasks were available concurrently during a 5-min multiple-stimulus assessment. By contrast, all participants exhibited high levels of engagement in most tasks when the tasks were presented singly for 5 min, and these data showed a high degree of correspondence with those obtained during extended (60-min) vocational assessments.