Best Practices in Utilizing the Changing Criterion Design.

The changing criterion design (CCD) has been a recognized format of single-case research for four decades. Published examples of the CCD have been limited and the structure of the design used in the literature has varied to a degree that might engender confusion. This review examines the structure of CCD studies published to date to identify prior implementation practices and identify best practices for future use.

Efficacy of a methylphenidate transdermal system versus t.i.d. methylphenidate in a laboratory setting.

OBJECTIVE: To test the efficacy and tolerability of the methylphenidate transdermal formulation (MTS) against immediate-release methylphenidate (IR MPH) and placebo in a 12-hr analog classroom setting. METHOD: A total of nine boys ages 6 to 9 years, medicated with MPH for ADHD, complete a within-subject, double-blind study. For the purpose of the study, the boys are administered a dose of 20 cm(2) MTS, a matched dose of IR MPH 10 mg TID, and placebo. ADHD symptoms and frequency counts of classroom rule violations and the number of math problems completed are assessed hourly, during three consecutive analog classroom sessions. RESULTS: Findings show that, across measures and throughout the day, both treatments significantly differentiated from placebo (p < .05) but not from each other. It is also observed that the MTS produced more consistent results across the day but had a delayed onset versus IR MPH. Both medications are well tolerated with only mild reductions in sleep onset. CONCLUSION: The MTS demonstrates comparable efficacy and tolerability to TID IR MPH.

A group contingency program to improve the behavior of elementary school students in a cafeteria.

Studies of behavior modification interventions for disruptive behavior in schools have generally focused on classroom behavior with less research directed toward child behavior in other school settings (e.g., cafeterias). The present report documents the effect of a group contingency intervention with a random reward component, targeting disruptive cafeteria behavior. An uncontrolled study of the effect of the group contingency program across the school year suggested substantial behavior improvement after the program started. Two natural treatment discontinuations during the same school year provide further support for the intervention. Both sources of information suggest behavioral improvement in rule-following behavior when the program was actively implemented.

Carryover effects of free reinforcement on children's work completion.

Patterns of behavior that persist during transition to a new set of contingencies are referred to as reinforcement history or carryover effects. The authors examined the carryover effects of a fixed-time (FT) schedule of free reinforcement on children's work completion and accuracy. Two female students with learning disabilities participated. During an initial concurrent-choice condition, both children completed more difficult problems reinforced on a richer schedule than easy problems reinforced on a leaner schedule. Exposure to an FT schedule was alternated with subsequent choice conditions in an ABABA design to examine potential carryover effects. During FT conditions, the children completed both types of problems with more errors. During subsequent choice conditions, errors were high initially but decreased, and both children completed easy problems for the first few sessions despite their leaner reinforcement schedule. The potential for detrimental effects of free reinforcement on children's work completion is discussed.

Sensitivity of children's behavior to probabilistic reward: effects of a decreasing-ratio lottery system on math performance.

Probabilistic reward has been shown to affect children's choice behavior in game-like activities. We examined the effects of a lottery system containing progressively lower exchange ratios on children's completion of math problems. Two of the 3 children completed problems above baseline levels until the chance of exchange dropped to 25%. This study describes a potentially useful method for examining reinforcement schedules in applied settings and extends previous research on probabilities of reinforcement.