A Critical Review of the Support for Variability as an Operant Dimension

Effect of signaled reinforcement on response variability

Three experiments examined the effect of signaling reinforcement on rats' lever pressing on contingencies that reinforced variable responding to extend the exploration of signaled reinforcement to a schedule that has previously not been examined in this respect. In Experiment 1, rats responding on a lag-8 variability schedule with signaled reinforcement displayed greater levels of variability (U values) than rats on the same schedule lacking a reinforcement signal. In Experiment 2, rats responding on a differential reinforcement of least frequent responses schedule also displayed greater operant variability with a signal for reinforcement compared with rats without a reinforcement signal. In Experiment 3, a reinforcement signal decreased the variability of a response sequence when there was no variability requirement. These results offer empirical corroboration that operant variability responds to manipulations in the same manner as do other forms of operant response and that a reinforcement signal facilitates the emission of the required operant.

Basic and applied research on extinction bursts

Discontinuation of the contingency between a response and its reinforcer sometimes produces a temporary increase in the response before its rate decreases, a phenomenon called the extinction burst. Prior clinical and basic studies on the prevalence of the extinction burst provide highly disparate estimates. Existing theories on the extinction burst fail to account for the dynamic nature of this phenomenon, and the basic behavioral processes that control response bursting remain poorly understood. In this paper, we first review the basic and applied literature on the extinction burst. We then describe a recent refinement of the concatenated matching law called the temporally weighted matching law that appears to resolve the above-mentioned issues regarding the extinction burst. We present illustrative translational data based conceptually on the model. Finally, we discuss specific recommendations derived from the temporally weighted matching law regarding procedures clinicians could implement to potentially mitigate or prevent extinction bursts.

A retrospective 60-year review of Murray Sidman's Tactics of Scientific Research and some of its influence on behavior analysis

Murray Sidman's book, Tactics of Scientific Research: Evaluating Experimental Data in Psychology, published in 1960, has been called the bible of the experimental analysis of behavior and has been a major influence on basic as well as applied research in behavior analysis. The contents of the early reviews of the book are summarized and the commemoration in The Behavior Analyst at the 30^th anniversary of the book is reviewed along with Sidman's comments on updates that he would have made if he were to revise or supplement the book. Included are some later remarks by Sidman regarding specific issues in Tactics. Continuous rates of citations are displayed and show the sustained relevance of the book, and selected themes from the book are discussed. Finally, experiences from using Tactics in lab courses and in graduate-level courses on scientific method are recapitulated, including questions raised by students, and Sidman's answers to those questions. Tactics is a true classic in behavior analysis.