Background: Identifying items that can be used as reinforcers is a critical component of treatments for autism, because they are used to teach language, social skills and other important behaviors. There has been growing interest in the autism treatment literature in identifying methods for assessing reinforcer efficacy, which refers to the degree to which a stimulus increases such behaviors when delivered as a consequence (Trosclair-Lasserre, Lerman, Call, Addison, & Kodak 2008). Unfortunately, reinforcer efficacy analyses are too laborious to conduct in most treatment situations. Instead, preference assessments serve as a method of efficiently predicting which stimuli have adequate reinforcer efficacy for treatment applications. Most preference assessment methods identify preferences based on choice, and differ primarily in the manner in which the stimuli are presented. The paired-stimulus (PS; Dattilo, 1986; Fisher et al., 1992) and multiple stimulus without replacement (MSWO; Windsor, Piche, & Locke, 1994) are two of the most commonly used preference assessments. However, research has shown that a daily MSWO may have greater correspondence with reinforcer efficacy than a PS (DeLeon et al., 2001). Unfortunately, this prior research measured reinforcer efficacy using another choice arrangement. Recently, progressive ratio (PR) arrangements have been identified as a more effective means of measuring reinforcer efficacy (Bickel & Madden, 2006). In a PR arrangement, the item is delivered following increasingly effortful responses until the individual discontinues responding. The PR arrangement then gauges how hard the individual will work for a particular stimulus, and this serves as a better measure of reinforcer efficacy. Yet, to date, there have been no comparisons of how well the MSWO and PS preference assessments each predict reinforcer efficacy as measured by a PR arrangement.
Objectives: The objective of the current study was to evaluate the extent to which results of MSWO and PS assessments each correspond with reinforcer efficacy as measured by a PR arrangement.
Methods: A single PS preference assessment was administered to each participant by presenting trials consisting of a choice between two potential reinforcers until each of six items had been paired with every other item. Following the PS, a daily MSWO was conducted by presenting the same items all at once and allowing participants to select one. Following each selection the selected item was removed from the array and the remaining items were re-presented until all items had been selected. On each day the MSWO was administered, participants also worked for each stimulus within a PR arrangement.
Results: The correspondence between results of each preference assessment and the PR analysis were examined using a statistical analysis consisting of Kendall’s-Tau. Statistically significant (α<.01) correlations were demonstrated between results of the PR arrangement and both preference assessment formats. However, unlike previous studies, results of both preference assessments showed approximately equal correlations with results of the PR arrangement (PS: T=.35; MSWO: T=.39).
Conclusions: Although both preference assessments predicted reinforcer efficacy equally well, the PS took less time to administer than a daily MSWO. Thus, clinicians may find the PS a more efficient method of identifying likely reinforcers.