Within-session Changes In Responding During Concurrent Variable-interval Schedules

Five rats and 4 pigeons responded for food delivered by several concurrent variable-interval schedules. The sum of the rates of reinforcement programmed for the two components varied from 15 to 480 reinforcers per hour in different conditions. Rates of responding usually changed within the experimental session in a similar manner for the two components of each concurrent schedule. The within-session changes were similar to previously reported changes during simple schedules that provided rates of reinforcement equal to the sum of all reinforcers obtained from the concurrent schedules. The number of changeovers also changed within sessions in a manner similar to the changes in instrumental responding. These results suggest that changeovers are governed by the same variables that govern instrumental responding. They also suggest that the within-session change in responding during each component of a concurrent schedule is determined by approximately the sum of the reinforcers obtained from both components when both components provide the same type of reinforcer.     

ITEM GENERATION PROCEDURES AND BACKGROUND DATA SCALES: IMPLICATIONS FOR CONSTRUCT AND CRITERION-RELATED VALIDITY

Background data measures are one of the best predictors of job performance. Nonetheless, questions have been raised about their content and construct validity. The present effort describes a set of procedures for developing construct and content valid background data items. Data gathered in seven field studies and six laboratory studies are presented bearing on the reliability and validity of the measures constructed using these item generation procedures. Findings in these studies indicate that construct-based item generation procedures yield reliable scales evidencing both content and construct validity. Furthermore, these scales are capable of predicting performance in a variety of settings. Theoretical and practical implications of these findings for the development and validation of background data measures are discussed.     

Some uniqueness results for PARAFAC2

Whereas the unique axes properties of PARAFAC1 have been examined extensively, little is known about uniqueness properties for the PARAFAC2 model for covariance matrices. This paper is concerned with uniqueness in the rank two case of PARAFAC2. For this case, Harshman and Lundy have recently shown, subject to mild assumptions, that PARAFAC2 is unique when five (covariance) matrices are analyzed. In the present paper, this result is sharpened. PARAFAC2 is shown to be usually unique with four matrices. With three matrices it is not unique unless a certain additional assumption is introduced. If, for instance, the diagonal matrices of weights are constrained to be non-negative, three matrices are enough to have uniqueness in the rank two case of PARAFAC2. The authors are obliged to Richard Harshman for stimulating this research, and to the Associate Editor and reviewers for suggesting major improvements in the presentation.     

Objectively reliable subjective probabilities

Subjective Bayesians typically find the following objection difficult to answer: some joint probability measures lead to intuitively irrational inductive behavior, even in the long run. Yet well-motivated ways to restrict the set of reasonable prior joint measures have not been forthcoming. In this paper I propose a way to restrict the set of prior joint probability measures in particular inductive settings. My proposal is the following: where there exists some successful inductive method for getting to the truth in some situation, we ought to employ a (joint) probability measure that is inductively successful in that situation, if such a measure exists. In order to do show that the restriction is possible to meet in a broad class of cases, I prove a Bayesian Completeness Theorem, which says that for any solvable inductive problem of a certain broad type, there exist probability measures that a Bayesian could use to solve the problem. I then briefly compare the merits of my proposal with two other well-known proposals for constraining the class of admissible subjective probability measures, the leave the door ajar condition and the maximize entropy condition.The author owes special thanks to Kevin Kelly, for a number of helpful ideas for the proof of the Bayesian Completeness Theorem, as well as other aspects of the paper. Thanks also to Clark Glymour for some helpful suggestions for improvement of an earlier draft. Part of the work leading to this paper was funded by a Summer Research Grant from the University Research Institute of the University of Texas at Austin.     

Agency and obligation

The purpose of this paper is to explore a new deontic operator for representing what an agent ought to do; the operator is cast against the background of a modal treatment of action developed by Nuel Belnap and Michael Perloff, which itself relies on Arthur Prior's indeterministic tense logic. The analysis developed here of what an agent ought to do is based on a dominance ordering adapted from the decision theoretic study of choice under uncertainty to the present account of action. It is shown that this analysis gives rise to a normal deontic operator, and that the result is superior to an analysis that identifies what an agent ought to do with what it ought to be that the agent does.     

Culturally Sensitive AIDS Educational Videos for African American Audiences: Effects of Source, Message, Receiver, and Context

The importance of using culturally sensitive educational materials in HIV-related interventions with racial and ethnic minority groups is widely recognized. However, little empirical research has been conducted to assess the relative effectiveness of different techniques for creating culturally sensitive AIDS educational videos. Two field experiments with three samples of African American adults (N = 174, 173, and 143) were conducted to assess how source characteristics (race of communicator), message characteristics (multicultural message vs. culturally specific message), and audience characteristics (racial distrust and AIDS-related distrust) influence proximate (perceptions of the message's credibility and attractiveness) and distal (AIDS-related attitudes, beliefs, and behavioral intentions) output variables for AIDS educational videos. In Study 1, an AIDS video with a culturally specific message was rated as more credible, more attractive, and of higher quality than was a video with a multicultural message. The multicultural message was rated less favorably when delivered by a White announcer than when the announcer was Black. In Study 2, the same pattern was replicated with a second community sample and a campus-based sample. Study 2 also indicated that a multicultural message might be more effective if delivered in a culturally specific context, namely, after audience members watch a culturally specific video. Minimal changes were observed in distal outcome variables. It is argued that influencing proximate output variables is necessary, though not sufficient, for effecting long-term change in AIDS-related attitudes, beliefs, and behaviors.     

Social-Cognitive and Behavioral Correlates of Aggression and Victimization in Boys' Play Groups

A contrived play group procedure was utilized to examine the behavioral and social-cognitive correlates of reactive aggression, proactive aggression, and victimization via peers. Eleven play groups, each of which consisted of six familiar African-American 8-year-old boys, met for 45-min sessions on five consecutive days. Social-cognitive interviews were conducted following the second and fourth sessions. Play group interactions were videotaped and examined by trained observers. High rates of proactive aggression were associated with positive outcome expectancies for aggression/assertion, frequent displays of assertive social behavior, and low rates of submissive behavior. Reactive aggression was associated with hostile attributional tendencies and frequent victimization by peers. Victimization was associated with submissive behavior, hostile attributional bias, reactive aggression, and negative outcome expectations for aggression/assertion. These results demonstrate that there is a theoretically coherent and empirically distinct set of correlates associated with each of the examined aggression subtypes, and with victimization by peers.     

A model for the study of research and education in a transdisciplinary context

In an evaluation project at the Goteborg University, we have looked at the relationship between individual and collective production of knowledge within the Health sciences in order to facilitate a common ground for a Academy of Health Sciences. We found obstacles for developing an environment which could stimulate multilateral co-operation and creativity. Some of these obstacles have their root in the different cultural backgrounds indicated in the analysis and makes it difficult to find common aims and strategies. The Model used makes the organizations’ activities visible and encouraging transdisciplinary contacts and improve organizational, structural and ideological decision making emanating from overall policies of the boards concerned.     

Personal Theories of Hunger and Eating1

Recent research on hunger and eating has shown that (a) among individuals with adlibitum access to food, hunger and eating are not regulated by deviations in the body's energy resources from set-points, and (b) it is healthier for people to consume their daily caloric intake as several small snacks than as 3 large meals. People's beliefs about hunger and eating were assessed in 2 questionnaire studies. In Study 1, a large sample of undergraduates was surveyed; in Study 2, dietetics students, nursing students, medical students, dietitians, nurses, and doctors were surveyed. Both studies revealed that people's personal theories of hunger and eating were inconsistent with research findings in ways that could promote overconsumption. These results suggest that educational programs designed to modify the beliefs about hunger and eating of people suffering from problems of overconsumption and of health professionals who treat problems of overconsumption may increase the effectiveness of current treatment regimens.     

AUGMENTING SIMPLIFIED HABIT REVERSAL WITH AN AWARENESS ENHANCEMENT DEVICE: PRELIMINARY FINDINGS

The chronic hair pulling of a 36-year-old woman with moderate mental retardation was initially treated with a simplified habit-reversal (SHR) procedure that consisted of awareness training, competing response training, and social support. When SHR did not produce large and sustained reductions in hair pulling, an awareness enhancement device was added, and it reduced hair pulling to near-zero levels in two settings. The results are discussed, and directions for future research with this device are provided.