Your search

Comparisons of service use and treatment outcomes for 145 black and 236 white homeless veterans with mental disorders showed few differences. A greater improvement in psychiatric symptoms and alcohol problems among white than black veterans did not hold true when black veterans had participated in the residential treatment component of the program. The implications of the findings for the successful treatment of homeless black veterans are discussed.

In two experiments with pigeons, a single variable-interval schedule assigned reinforcers to two response keys on a percentage basis. The percentage of reinforcers assigned to each key was changed every few sessions, and subjects' choice responses were recorded before and after each change. In Experiment 1, the overall rate of reinforcement was varied across conditions The pigeons' choice responses adapted more quickly to a change in the reinforcement percentages when the overall reinforcement rates were higher, but acquisition rates varied by only about a factor of 3, whereas reinforcement rates were varied by about a factor of 9. In Experiment 2, the reinforcement percentages changed about every 8 sessions in Phases 1 and 3, but every 1 or 2 sessions in Phase 2. Pigeons' choice responses adapted to a change in reinforcement percentages more quickly in Phase 2 than in Phases 1 and 3. The results from both experiments pose difficulties for several prominent models of transitional choice behaviour. The results suggest that each successive reinforcer has more impact on a subject's subsequent choice behaviour when the overall rate of reinforcement is lower and when the reinforcement contingencies have changed frequently in the recent past.

Choice responding refers to the manner in which individuals allocate their time or responding among available response options. In this article, we first review basic investigations that have identified and examined variables that influence choice responding, such as response effort and reinforcement rate, immediacy, and quality. We then describe recent bridge and applied studies that illustrate how the results of basic research on choice responding can help to account for human behavior in natural environments and improve clinical assessments and interventions.

This 2-year longitudinal study examined the affective nature of communication between mothers and adolescents from early to mid-adolescence. Eleven-to 16-year-old adolescents and their mothers were videotaped while engaging in conversations about everyday topics, dating and sexuality, and conflicts. Nonverbal displays of affiliation, embarrassment, and contempt were found to be fairly stable across conversations, across members of the same dyad, and across time for the mothers. However, there were some effects of conversational topic in that adolescents displayed less affiliation in the conflict conversation than in the other conversations during the 1st session. In addition, boys displayed more contempt when talking about dating and sexuality than about conflicts. Over the 2-year period, the level of affiliation decreased for adolescents, and maternal conversational dominance increased. In all conversations and at both time periods, adolescents displayed more embarrassment and contempt and less affiliation than did mothers. Both maternal and adolescent levels of affiliation during the conversations in the 1st session predicted degree of satisfaction with certain family characteristics expressed in the 2nd session. Copyright © 1997, Lawrence Erlbaum Associates, Inc.

The hyperbolic-decay model is a mathematical expression of the relation between delay and reinforcer value. The model has been used to predict choices in discrete-trial experiments on delay-amount tradeoffs, on preference for variable over fixed delays, and on probabilistic reinforcement. Experiments manipulating the presence or absence of conditioned reinforcers on trials that end without primary reinforcement have provided evidence that the hyperbolic-decay model actually predicts the strength of conditioned reinforcers rather than the strength of delayed primary reinforcers. The model states that the strength of a conditioned reinforcer is inversely related to the time spent in its presence before a primary reinforcer is delivered. A possible way to integrate the model with Grace's (1994) contextual-choice model for concurrent-chain schedules is presented. Also discussed are unresolved difficulties in determining exactly when a stimulus will or will not serve as a conditioned reinforcer.

The primary purposes of this study were to identify the best teaching practices for adult baccalaureate (BSN) nursing students and to examine if adult students' teaching preferences differed from those of traditional BSN students. The sample consisted of 206 adult and traditional students in four BSN programs. The adult nursing student sample was further subdivided into two groups: adults with no prior nursing education (adult non-nurses) and adults with prior nursing education (RN'S). Using a two-part, self-administered questionnaire, respondents were asked to rate the frequency with which 41 teaching strategies were used in their best and in their worst classroom learning experiences in nursing. In most cases, adult non-nurses' teaching preferences did not vary significantly from the preferences of traditional students. However, adults with no prior nursing education did show a preference for knowledgeable and organized instructors. In contrast RNs' preferred classroom situations were where time on task was emphasized, cooperative learning was encouraged, and expectations for learning were high. Results indicate that classroom teaching preferences vary as a function of prior experience with the subject matter and are not attributable to age itself. Findings suggest that prior experience with course content is a more important consideration in planning programs than generalized adult experience.

A growing body of literature suggests that experts are little if at all better than novices in terms of the quality of decision outputs, To explain this counter-intuitive finding, the authors propose a conceptual framework that focuses on initial problem structure as a key moderator of the effect of expertise on performance, Specifically, they argue that the expert-novice performance differential should be greatest at moderate levels of problem structure and weakest at both extremes. To examine this central hypothesis, the authors conduct a controlled experiment that compares experts with novices when solving a complex problem that had characteristics of a moderately ill-structured problem, Relative to novices, the authors find that experts select fewer, but more diagnostic, information inputs and are more consistent when evaluating nonquantified inputs, As a result, they make more accurate and tightly clustered judgments than do novices, and. also are more confident in their decisions. To examine the moderating influence of problem characteristics, certain task variables are manipulated to increase or decrease initial problem structure. As hypothesized, the benefits of expertise are less pronounced when solving a problem with increased initial structure.