Operant variability: A conceptual analysis

Abstract

Some researchers claim that variability is an operant dimension of behavior. The present paper reviews the concept of operant behavior and emphasizes that differentiation is the behavioral process that demonstrates an operant relation. Differentiation is conceived as change in the overlap between two probability distributions: the distribution of reinforcement probability as a function of some response property (S distribution) and the probability distribution of the response property itself (R distribution). This concept implies that the differentiation process can be measured only if S distribution and R distribution are both established on the same response property. To determine whether the differentially reinforced behavioral variability fits the proposed concept of operant behavior, I examine the main procedures (lag n and threshold procedures) and the main dependent variable (U value) employed in the studies of operant variability. Because lag n and threshold procedures establish their S distributions on properties distinct from U value, differentiation cannot be measured over the change in U value. I conclude that studies of operant variability have failed to provide a direct demonstration that variability is an operant dimension of behavior. Hence, studies in which measures of variability provide a basis to measure differentiation can better support the claim that variability is an operant dimension of behavior.

Selective attention in dairy cattle

“…Barba (2012) pointed out that the calculation of U-values based on the complete set of possible response options or categories might not be appropriate when only some of the options are used. The second analysis confirmed his concern.…”

Choice Under Conditions of Uncertainty

“…Although Machado observes variability that he cannot account for, he writes that "we cannot rule out the hypothesis that [schedule-behavior dynamics] underlay the differences in the degree of sequence variability across the three experiments" (p. 22). Barba (2012) is even more forceful in claiming that behavioral variability must be explainable: "Even if a contingency increases levels of behavioral variability but in fact differentially reinforces some sequences on the basis of properties other than their variability, the increase in variability levels, whatever it is, does not allow one to measure a differentiation process. In this case, the increase in variability represents a secondary effect of differential reinforcement" (p. 222, italics mine).…”

Behavioral variability as avoidance behavior

“…demonstrated that behavioral variability can be selected by its consequences and suggested that variability is an operant dimension of behavior. Despite some alternative analyses of this issue (Barba, 2012a(Barba, , 2012b(Barba, , 2014Machado, 1989Machado, , 1992Machado, , 1993Machado, , 1997Machado & Tonneau, 2012), the operant variability interpretation has been largely supported across the years (for a review, see Neuringer & Jensen, 2012). Most studies have investigated the selection of variable behavior patterns by positive reinforcement contingencies (Neuringer & Jensen, 2012).…”