Self-punitive responding in rats with goal shock and color change

After acquisition avoidance training, rats were assigned on the basis of matched run speed to the following groups: (1) maintenance of avoidance training, (2) extinction procedures with the addition of a brief shock in the goalbox, and (3) regular extinction procedures. Each group was further divided into two minor groups which experienced either change or no change in goalbox color. The results indicated : (1) that self-punitive responding was increased by goal shock, (2) that self-punitive responding was reduced by goalbox color change, and (3) that generalization of goal shock to the startbox and runway areas is a factor in self-punitive responding.     

Instrumental escape learning in the rat at 24-hour intertriai interval: Effects of magnitude and schedule of reinforcement

Three experiments investigated the effects of magnitude and schedule of reinforcement and level of training in instrumental escape learning at a 24-h intertriai interval. In Experiment I, two magnitudes of reinforcement were factorially combined with two schedules of reinforcement (CRF and PRF). Under PRF, large reward produced greater resistance to extinction than did small reward, while the reverse was true under CRF. In Experiment II, two levels of acquisition training were factorially combined with three schedules of reinforcement (CRF, single-alternation, and nonalternated PRF). Patterned running was observed late in acquisition in the single-alternation extended-training condition. Resistance to extinction was greater for the nonalternated PRF condition than for the single-alternation condition following extended acquisition, and the reverse was true following limited acquisition. Experiment III confirmed the extinction findings of Experiment II. The results of all three experiments supported an analysis of escape learning at spaced trials in terms of Capaldi’s (1967) sequential theory.     

The evaluation from the program director's viewpoint

In considering the evaluation of the preceptorship and residency programs, our faculty were asked to react to specific dimensions and aspects of the studies. Viewpoints about these data were submitted in formal critiques which will be summarized only briefly here. A number of the comments were in response to specific questions which had been posed; other were spontaneous from the faculty.     

Variation in class size,the class size paradox,and some consequences for students

Even where a total allocation of resources is fixed, it is often possible to vary the distribution of the given resources. This distribution can have important, if sometimes hidden, consequences. In the case of universities, considering the mean class size as given, three nonobvious consequences of the amount of variation in class size are examined. (1) The average class size experienced by students is directly related to the amount of variation in class size. (2) Overall student attendance is inversely related to the amount of variation in class size. (3) Overall student participation time is directly related to the amount of variation in class size. The logic of these relationships is explored, and data on 49 departments and interdisciplinary programs at one university are used to illustrate the nature and extent of the class size paradox at one university.     

Intellectual development within transracial adoptive families: retesting the confluence model

The confluence model of intellectual development was estimated for a within-family sample of 321 children from 101 transracial adoptive families. Mental ages of the children and their parents, as well as birth or adoption intervals, were used in a nonlinear least-squares estimation procedure to obtain children's predicted mental ages. Contrary to an earlier report using these data, the confluence model performed quite well, accounting for up to 50% of the variance in mental age. When the relationship between chronological and mental age was taken into account, the predictive power of the model was reduced but not eliminated. The confluence model was also fitted separately to various subsamples. The model generated a good fit to the data from both biological and adopted children and fit the data from early-adopted children much better than the data from later-adopted children. Both findings were taken as evidence that the confluence model provides an environmental account of intellectual development within the family.     

Masculinity and femininity in twin children: genetic and environmental factors

Genetic and environmental origins of individual differences in masculine and feminine personality attributes were investigated in a sample of 38 monozygotic and 32 dizygotic twin pairs (total N = 140) during pre- and early adolescence. Self-report measures of both masculine and feminine characteristics were obtained for each child using 2 standardized instruments: the Children's Personality Attributes Questionnaire (CPAQ) and the Adolescent Self-Perception Inventory (ASPI). Multivariate biometrical analyses revealed significant genetic influences in all measures, accounting for 20%-48% of the observed variation in each. Environmental influences, which explained the remaining 52%-80% of variance in masculinity and femininity, were apparently specific to each individual and not shared by members of the same twin pair. The results underscore the importance of considering both genetic and environmental factors in gender-role development, particularly in studies of family resemblance.     

The Effects of Information and Feedback on Teachers’ Classroom Behaviour and Students’ Academic Engaged Time

Research has shown a positive relationship between academic engaged time (AET), academic learning time (ALT) and student achievement. Previous work has reported a relatively non‐intrusive, cost‐effective method for increasing AET in the classroom involving the presentation of research information followed by feedback to teachers of students’ AET in their classes. This study aimed to replicate these findings in a primary school setting and to establish what effects the information plus feedback had on teachers’ instructional behaviours which have been found to correlate with students’ AET and ALT. In addition, we looked at the effects of more precise feedback based on students’ task difficulty measures. The results provided strong support for the utility and efficacy of information plus feedback as a method for increasing student AET and ALT and for enabling teachers to change their instructional behaviours in the direction of published research findings.