The behavior equivalence problem in within-subject treatment comparisons

Within-subject comparisons of multiple treatment effects raise a variety of issues for applied researchers. They include potential nonreversibility of behaviors, practice or habituation effects resulting from repeated presentations of the same stimulus, and the possibility of multiple-treatment interference. It has recently been suggested that the use of item cohorts with equivalent behavioral difficulty addresses those problems. In order to meet the needs of researchers whose primary interest is in domestic, vocational, or other nonacademic skills, a procedure is described for estimating equivalent difficulty for different vocational preparation tasks.