The effects of delayed auditory feedback on the overt behaviors of stutterers

This study investigated the differential effect of delayed auditory feedback (DAF) upon general (e.g., repetitions) and specific (e.g., repetitions of initial, medial, and final syllables) overt types of dysfluent behaviors. Ten moderate to severe stutterers performed an oral reading task under both NDAF and DAF (200 msec). DAF resulted in a significant increase in the total number of dysfluencies but had a differential effect upon certain general and specific behaviors. Blocks decreased significantly, prolongations increased significantly, and repetitions and interjections did not change significantly in frequency of occurence. To a limited extent, DAF had a differential effect on specific behaviors. All specific prolongation behaviors increased significantly while only one specific block behavior (ddelays in starting words) decreased. The authors discuss these results in terms of the vocal changes that occurred under DAF and speculate as to their importance in establishing fluency. DAF is viewed as promoting prolongations and prolongations are viewed as inhibiting excessive stoppages of the breathstream, thus promoting fluency (e.g., delays in starting words).     

BEHAVIOR ANALYSIS APPLIED TO ENVIRONMENTAL/ECOLOGICAL PROBLEMS; A REVIEW1

Recent applications of operant technology, including the manipulation of environmental conditions and response consequences, have been directed toward the improvement of man-environment relations. This document summarizes the research designs, procedures, results, and conclusions of these recent behavioral interventions for ecological rebalance. Each of the 32 studies reviewed was undertaken since 1970; all studies were relatively successful in changing the probability of an ecology-related response; all studies incorporated basic methodologies applicable for large-scale, community programs; most of the investigations were conducted in field settings (e.g., college campuses, grocery stores, mobile-trailer parks, homes, movie theaters, public campgrounds, and a football stadium). Several of the studies are as yet unpublished. Sources for receiving documentation of the unpublished research are provided in this document. About 50% of the investigations reviewed were designed to influence behaviors related to environmental litter; the others were of behavior-modification programs that substantially increased bus-ridership, decreased lawn-trampling, promoted the purchase of drinks in returnable rather than throwaway containers, initiated a recycling process, or reduced energy consumption. Essentially, the interventions were either preventive in nature (i.e., designed to discourage environment-destructive behaviors before they occur), or remedial (i.e., designed to encourage behaviors that correct an existing environmental problem). Usually, the preventive measures emphasized responses priming (or prompting), while the corrective measures applied some form of positive reinforcement. Response priming was accomplished with modelling techniques, or with written and/or verbal prompts presented either publicly or on a personal, one-to-one basis. Among the positive reinforcement procedures were field applications of token economies, lottery systems, feedback programming, and intergroup contests, as well as individual contingency contracting. Some experimental designs provided for comparisons between the behavioral effects of response priming and positive reinforcement.     

MODIFICATION OF THE EXCESSIVE INAPPROPRIATE CLASSROOM BEHAVIOR OF TWO ELEMENTARY SCHOOL STUDENTS USING HOME-BASED CONSEQUENCES AND DAILY REPORT-CARD PROCEDURES1

Two experiments investigated home-based reinforcement contingencies to control excessive behavior in normal classrooms. Subjects were, respectively, a 12-yr-old fifth-grade boy and a 9-yr-old fourth-grade boy, each in a separate classroom and with a different teacher. Following baseline observations in which observers recorded several categories of student behavior and teacher-student interaction, separate conferences were held including parents of the two children, the principal, teachers, and experimenters. A daily report-card procedure was agreed on, stipulating a one-day suspension from school following three successive “undesirable” daily report cards as well as the supervision of home-based privileges and other reinforcers usually contingent on satisfactory daily reports. Measurements of daily rates of teacher attention indicated no important change in this variable throughout the various experimental conditions. The daily report procedure significantly reduced disruptive classroom behavior. In a second experiment, a teacher-operated timer cued her own time-sample observations. Reliability measures revealed that the teacher could accurately measure the child's behavior while she was teaching the class. The procedure was ultimately successfully expanded to the teacher's total contact hours each day.     

GPS: A Randomized Controlled Trial of Sexual Health Counseling for Gay and Bisexual Men Living With HIV

Gay, bisexual, and other men who have sex with men (GBM) continue to have high rates of HIV and sexually transmitted infections, including syphilis. GBM have therefore been identified by public health agencies as a high-priority population to reach with prevention initiatives. Despite the importance of mental health in preventing HIV and related infections, there is a shortage of credentialed mental health professionals to deliver behavioral Counseling interventions. The current study evaluated the efficacy of GPS, a community-based and peer-delivered sexual health promotion motivational interviewing–based intervention for HIV-positive GBM who engaged in condomless anal sex (CAS) in the past 2 months. GPS prevention counseling demonstrated a 43% relative reduction at 3-month follow-up in CAS with serodiscordant partners and significant reductions in sexual compulsivity. The study demonstrated that community-based counselors can administer an efficacious motivational interviewing program, and suggests a continued benefit of counseling methods to promote the sexual health of higher risk populations.     

When is the Wilcoxon–Mann–Whitney procedure a test of location? Implications for effect-size measures

The Wilcoxon–Mann–Whitney procedure is invariant under monotone transformations but its use as a test of location or shift is said not to be so. It tests location only under the shift model, the assumption of parallel cumulative distribution functions (cdfs). We show that infinitely many monotone transformations of the measured variable produce parallel cdfs, so long as the original cdfs intersect nowhere or everywhere. Thus there are infinitely many effect sizes measured as shifts of medians, invalidating the notion that there is one true shift parameter and thereby rendering any single estimate dubious. Measuring effect size using the probability of superiority alleviates this difficulty.