Group aggregates and individual reliability: The case of verbal short-term memory

Two experiments examined the generalizability of the effects of word length and phonological similarity with visual and auditory presentation in immediate verbal serial ordered recall. In Experiment 1, data were collected from 251 adult volunteers drawn from a broad cross-section of the normal population. Word length and phonological similarity in both presentation modes significantly influenced the group means. However, 43% of the subjects failed to show at least one of the effects, and the likelihood that effects appeared was highly correlated with verbal memory span. In Experiment 2, 40 subjects of the original sample were retested, 20 of whom had failed to show one or more effects in Experiment 1. Whether or not an effect had appeared for individual subjects on the first test session was a poor predictor of whether the effect would appear on retest. Finally, an analysis of subject reports demonstrated that the patterns of experimental data could be accounted for in part by the strategies that subjects reported using, and the effect of strategy was independent of the effect of span. The implications of these findings for theories of verbal short-term memory are discussed.     

Interactive presentation in multitrial free recall

This paper explores whether free recall performance and organization can be facilitated using computer-controlled interactive presentation, where stimulus presentation on Trial N+1 depends on the individual subject’s prior recall history. A series of experiments investigated the effects of two types of response-contingent presentation order manipulations and of selective tagging manipulation designed to highlight the presentation of previously nonrecalled items. An initial experiment using 20-word lists showed no differences among groups, due to a ceiling effect. Two subsequent experiments, using longer lists (30 and 40 words), found that recall and subjective organization were increased by selective tagging and by presentation orders that preserved the subject’s prior order of recall. The results demonstrate that subjects’ previous recall histories contain information that can be used to facilitate recall. The potential of other interactive manipulations is discussed.     

Grade Expectations as a Function of Sex, Academic Discipline, and Sex of Instructor

Twelve hundred and fifty college students starting introductory courses in thirteen academic disciplines were asked to predict their grade in the course. Results showed that overall, males predicted higher grades for themselves than did females (p <.001). This held true for entering freshmen as well as for those with previous college experience. The phenomena was noted in 26 of 37 classes tested, including 7 of 9 in the natural sciences, 11 of 13 in the social sciences, but only 8 of 15 in the humanities. Sex of the instructor was irrelevant, raising the question of whether female instructors as role models have the positive effect upon women students that has been claimed. The differences found were slight, but persistent. Both sexes predicted very high grades. The data suggest that sex differences in prediction were not based on a female sense of incompetence, but upon a greater willingness among males to make highly positive predictions.     

A probe trial procedure for the study of children's discrimination learning and transfer

A discrimination reversal problem was presented to 192 children varying in age from 3 to 5 years. At the end of both the initial learning and transfer trials, probe trials were introduced to ascertain the response rule describing children's choices. Results were analyzed in terms of a binary division of the children according to their responses to the probe stimuli; children who responded errorlessly (concept responders) were contrasted with children who made errors on the probes (instance responders). Using this criterion, it was found that many children transferred in a way different from the way they learned the initial problem. There was no difference in the proportion of younger and older children responding conceptually to the original problem, but older children were more likely to transfer conceptually when standard geometric blocks were used as stimuli. Future studies must consider the possiblity that learning and transfer may be accomplished by different processes whose application differs with age, the nature of the stimuli, and the stage of training.     

Female Offenders Under Community Supervision: A Phenomenological Analysis

In this phenomenological study, we examined the lived experiences of 10 female offenders under community supervision. Findings include five essential themes. We propose clinical implications and actionable service recommendations for clinical mental health counselors working with this population.     

The danger of conflating level-specific effects of control variables when primary interest lies in level-2 effects

In the multilevel modelling literature, methodologists widely acknowledge that a level-1 variable can have distinct within-cluster and between-cluster effects, and that failing to disaggregate these can yield a slope estimate that is an uninterpretable, conflated blend of the two. Methodologists have stated, however, that including conflated slopes of level-1 variables in a model is not problematic if substantive interest lies only in effects of level-2 predictors. Researchers commonly follow this advice and use methods that do not disaggregate effects of level-1 control variables (e.g., grand mean centering) when examining effects of level-2 predictors. The primary purpose of this paper is to show that this is a dangerous practice. When level-specific effects of level-1 variables differ, failing to disaggregate them can severely bias estimation of level-2 predictor slopes. We show mathematically why this is the case and highlight factors that can exacerbate such bias. We corroborate these findings with simulations and present an empirical example, showing how such distortions can severely alter substantive conclusions. We ultimately recommend that simply including the cluster mean of the level-1 variable as a control will alleviate the problem.     

Stress and subjective life expectancy: Cross-sectional and longitudinal associations in early adolescence

Using data from a longitudinal study, the present study employed a latent class mover-stayer analytical strategy to examine both the cross-sectional and longitudinal (+33 months) relationship between membership of stress classes, and subjective life expectancy. Participants were from 21 High schools in Scotland and Northern Ireland. Data were collected in the first year of High school (mean age = 12.5 years), and at +33 months (fourth year, or school year 11). Sample 1 consisted of 1171 adolescents (40.82% females, 2.56% unreported) in Northern Ireland. Sample 2 consisted of 1059 adolescents (52.79% females, 1.32% unreported) in Scotland. Adolescents with the lowest levels of stress projected the highest subjective life expectancy scores. Longitudinal analyses were jumbled and not in keeping with cross-sectional results. More research may be needed on the trajectory of subjective life expectancy over time before it can be depended upon as a reliable outcome variable in adolescent development.