A Comparison of Baseline Procedures in Task Analyses.

Several methods for assessing baseline performance in chained tasks have been outlined in the literature, including the fixed-opportunity probe (FOP) and the multiple-opportunity probe (MOP). Concerns have been raised regarding how each of these methods might change the baseline performance of a task, affecting the interpretation of experimental control. The purpose of the current study was to conduct a within-subject comparison of both the FOP and MOP procedures for children with autism performing daily living and self-care skills. Results indicated that, for most participants, the MOP resulted in elevated performance during baseline compared to the FOP, and that for some participants the MOP resulted in acquisition prior to direct training. Because of the possibility that the FOP might result in suppressed baseline performance, it is recommended that in most cases clinicians and researchers use the MOP when assessing baseline performance in chained tasks in order to obtain the most accurate data.