A stochastic growth model applied to repeated tests of academic knowledge

In the course of the medical program at the University of Limburg, students complete a total of 24 progress tests, consisting of items drawn from a constant itembank. A model is presented for the growth of knowledge reflected by these results. The Rasch model is used as a starting point, but both ability and difficulty parameters are taken to be random, and moreover the logistic distribution is replaced by the normal. Both individual and group abilities are estimated and explained through simple linear regression. Application to real data shows that the model fits very well.     

Infants' interactions with professional caregivers at 3 and 6 months of age: a longitudinal study

This study longitudinally investigated the quality and stability of 64 infants’ interactions with their professional caregivers in child care centers at 3 and 6 months of age, i.e., across the first 3 months after they entered child care. It was also examined whether the infants’ negative emotionality (as rated by the mother) predicted the quality of the caregiver–infant interaction. The interactive behavior of the professional caregivers (sensitivity, cooperation) and the infants (responsiveness, involvement) was rated from videotapes recorded in three different caregiving situations, lasting about 25 min in total. In contrast to our expectation, the quality of the caregiver–infant interaction did not significantly increase across the first 3 months in child care. As expected, significant rank order stability was found for the quality of the caregivers’ behavior over time. Also in accordance with our expectations, infants with higher negative emotionality scores experienced less sensitivity and cooperation in interactions with their primary professional caregivers at both ages.     

Book Reviews

Pastoral Psychology -     

Bayesian Gaussian distributional regression models for more efficient norm estimation

A test score on a psychological test is usually expressed as a normed score, representing its position relative to test scores in a reference population. These typically depend on predictor(s) such as age. The test score distribution conditional on predictors is estimated using regression, which may need large normative samples to estimate the relationships between the predictor(s) and the distribution characteristics properly. In this study, we examine to what extent this burden can be alleviated by using prior information in the estimation of new norms with Bayesian Gaussian distributional regression. In a simulation study, we investigate to what extent this norm estimation is more efficient and how robust it is to prior model deviations. We varied the prior type, prior misspecification and sample size. In our simulated conditions, using a fixed effects prior resulted in more efficient norm estimation than a weakly informative prior as long as the prior misspecification was not age dependent. With the proposed method and reasonable prior information, the same norm precision can be achieved with a smaller normative sample, at least in empirical problems similar to our simulated conditions. This may help test developers to achieve cost-efficient high-quality norms. The method is illustrated using empirical normative data from the IDS-2 intelligence test.     

Developmental stimulation in child care centers contributes to young infants’ cognitive development

This study examined whether the quality of caregiver behavior in child care centers contributes to infant cognitive development at 9 months of age. Sixty-four infants (34 boys) were observed with their primary caregivers in child care centers at 3, 6, and 9 months of age. Caregiver behavior was rated for sensitivity and for stimulation of infant development during one-to-one caregiving interactions. Infant cognitive development was assessed using the Bayley Scales of Infant Development-II (Mental Development Index). Higher levels of developmental stimulation in the centers predicted higher levels of infant cognitive development at 9 months, beyond infant cognitive development at 3 months (just before entering child care), parental education, and maternal sensitivity. The results suggest that even small increases in developmental stimulation provided in child care centers in the first year of life may foster infants’ cognitive development.     

The equal division kernel: An equity approach to coalition formation and payoff distribution in N-person games

Most existing models of coalition formation and payoff distribution in groups rest upon normative considerations and are ambiguous in their predictions insofar as they do not determine which of several coalitions will most probably result. The paper sketches the basic features of a model derived from social psychological exchange-and equity-theory which predicts coalitions and payoff distributions for a variety of situations. The evaluation of the model by the results of several experiments indicates that it provides a reasonable starting point for further theoretical developments that are based empirical studies.     

Circadian organization of locomotor activity in the Turkish hamster (Mesocricetus brandti)

The circadian organization of locomotor activity was examined in Turkish hamsters while exposed to a light-dark (LD) cycle, constant illumination (LL), and following blinding and gonadectomy. Under LD 16:8 the activity rhythm of all hamsters became well entrained with activity beginning approximately 30 min after dark onset. In contrast, when activity rhythms free-ran as the result of exposure to LL or blinding, a variety of spontaneous perturbations in the period and/or phase of the activity rhythm were observed.     

Social competence and family environment: 15-year follow-up of disturbed adolescents

Measures of familial emotional climate and communication deviance, obtained when subjects were adolescents, were used to predict social adjustment 15 years later. The results showed that disturbed family functioning predicted poor quality of later intimate relationships, but did not predict other dimensions of adult social functioning.     

Is the three-term contingency trial a predictor of effective instruction?

Two experiments are reported which test the effect of increased three-term contingency trials on students' correct and incorrect math responses. Experiment 1 included two junior high school students in need of special instruction in mathematics while in Experiment 2 two other students with similar instructional needs from the same classroom were studied. In the first experiment the increased rate of presentation (3 times the baseline rate) was done without regard to whether the antecedent teacher presentations to the student were presented vocally or in written form; in the second experiment, the rates of presentation were systematically rotated across written and vocal presentations. The dependent variables were rate per minute of correct and incorrect responses of students (vocal or written). The experiments used designs incorporating features of the multiple baseline (Students A and B) and reversal (Students B, C, and D). The data showed that increasing the number of three-term trials increased correct rates while incorrect rates remained relatively low. The second experiment replicated these findings with two other students and found that the treatment effect occurred independently with vocal and written antecedents when each was isolated. The results warrant further research to test whether or not rates of presentation of three-term contingency trials are predictors of effective instruction.