The Random Stimulus Design

In the 1960s, a methodological advancement of significant proportion occured with the development of single case research designs in the field of appleid behavior analysis. Among the methods popularized were the multiple baseline, reversal, and, more recently, the alternating treatment designs. Despite the flexibility and wide applicability of each of these single subject designs, there are conditions under which none of them are appropriate. For example, when limited subjects are available and when repeated presentation of the same stimuli result in improvement due to practice effects of decremental effects due to boredom or habituation, problems arise. To offset this difficulty, the investigators describe a new single case design, the random stimulus design. This design is so named becuase an item pool of equal stimuli is established and then items are randomly selected and assigned to one of several cohorts. Cohorts are then assessed in the typical withdrawal or reversal manner.