Units of analysis in task-analytic research.

We develop and discuss four criteria for evaluating the appropriateness of units of analysis for task-analytic research and suggest potential alternatives to the units of analysis currently used. Of the six solutions discussed, the most commonly used unit of analysis in current behavior analytic work, percentage correct, meets only one of the four criteria. Five alternative units of analysis are presented and evaluated: (a) percentage of opportunities to perform meeting criterion, (b) trials to criteria, (c) cumulative competent performances, (d) percentage correct with competent performance coded, and (e) percentage correct with competent performance coded and a grid showing performance on individual steps of the task analysis. Of the solutions evaluated, only one--percentage correct with competent performance coded and a task analysis grid--met all four criteria.