Empirical bayes estimation of coefficients in the general linear model from data of deficient rank

Empirical Bayes methods are shown to provide a practical alternative to standard least squares methods in fitting high dimensional models to sparse data. An example concerning prediction bias in educational testing is presented as an illustration.The authors would like to thank the referees for several useful comments.The analysis of the data discussed in this report was part of a study funded jointly by the Graduate Management Admission Council and Educational Testing Service.     

A microcomputer interface to control reinforcement delivery

A method for interfacing a PET microcomputer to an operant arena is described.     

Paradoxical sleep in the dark period of the rat: a dissociation between electrophysiological and behavioral characteristics

Paradoxical sleep (PS) occurring in the dark period of the illumination cycle is studied in adult, male, Wistar rats. In contrast to the light period, behaviorally the rats give the impression of being awake at the onset of PS. This is caused by the fact that PS in the dark starts from a short-lasting state characterized by dissociating criteria: behavioral characteristics such as open eyes and body posture phenomena indicating quiet wakefulness along with full-blown hippocampal EEG waves implying slow wave sleep (SWS). These behavioral characteristics continue at the onset of PS, suggesting that PS in the dark differs from that in the light period. The intrinsic characteristics of PS, as the hippocampal theta rhythm, the suppression of the neck muscle EMG and the phasic activities, however, indicate that PS is the same phenomenon in both illumination periods. The implication of this finding with respect to the triggering of PS and its relationship with SWS is discussed.     

FAMILY-MOTIVATED TRUANCY

This study explores some determinants of truancy behavior among Nigerian primary school pupils. Comparing a sample of 100 truant pupils with a control group of non-truants drawn from the same population, the results of the study led to the following conclusions: the degree of domestic responsibilities determines to a significant extent pupils' school-attending behavior; truancy is a “disease of the poor”; truancy and academic success are mutually exclusive.     

Fear-Arousing and Empathy-Arousing Appeals to Help: The Pathos of Persuasion

An experiment tested the proposition that the components of a fear appeal which persuade us to protect ourselves are the Same components that persuade us to protect others. The results confirmed this hypothesis for the two components examined: noxiousness of the threatened danger and efficacy of coping response. Films showing noxious scenes of industrial whaling and films showing a pro-environmental action organization successfully saving whales from whalers strengthened intentions to help this endangered animal species. Taken together, available data indicate that fear appeals can persuade us to protect ourselves, other people, and even infrahuman animals. The social psychological paradigm used to investigate attitude change was merged with a paradigm employed to examine prosocial behavior. As predicted, an empathy-arousing appeal facilitated attitude change. Three implications for promoting ecological actions were discussed. First, empathy-arousing appeals can be applied to mass media campaigns. Second, the concept of response-efficacy in persuasive appeals can be extended from direct, individual action to activity requiring the mediation of social organizations. Finally, pro-environmental campaigns can be effective when the potential beneficiaries are not the ones shown, but who symbolize the many others in the same plight.     

EXPLAINING ROLE CONFLICT AND ROLE AMBIGUITY VIA INDIVIDUAL AND INTERPERSONAL VARIABLES IN DIFFERENT JOB CATEGORIES

The relationships between experienced role conflict and ambiguity and four individual and interpersonal variables were examined within a multivariate framework. The regressions of role conflict and ambiguity on these variables were significant and were generally supported across three job categories in one organizational setting. Differences were noted across the job categories in terms of the regression equation predicting role perceptions. Hence, it appears that the underlying equations regarding the influence of individual and interpersonal variables on role perceptions do vary in different job categories. Task characteristics are offered as plausible reasons for these variations and suggested as variables for inclusion in a model of role conflict and ambiguity.     

Individual differences in conceptual behaviour following manipulated controllability

Expectations of controllability are thought to influence subsequent behaviour, such that perceived non-contingency between behaviour and outcomes can produce a “learned helplessness” reaction by the organism. Since cognitive processes are implicated in this debilitation, the present study examines the influence of manipulated controllability upon the intrinsic individual differences (among females) in a disjunctive conceptual behaviour recovery task. Three-mode factor analysis is used to explore the process variability in a multivariate time-series design. Results indicate that intrinsic task processes are altered by the controllability pretreatment, but the nature of the impact reflects substantial individual differences in reaction.