Skew and internal consistency

The effects of skew on the standardized item alpha were examined with Monte Carlo techniques. Alphas computed from normal variables were compared with alphas from lognormal variables, ranks, and skewed versus normal Likert-type variables. The extent and direction of skew were varied, as was the size of the population interitem correlation (rho), the number of items, and the number of categories for Likert-type variables. Because the average interitem correlation affects alpha and skew affects the average interitem correlation, the effect of skew on the average interitem correlation also was examined. Results indicated that skew decreased the average interitem correlation and produced small decreases in alpha that were largest when skew was large, rho was small, items were skewed in opposite directions, and there were fewer items.     

Conceptualizing the Influence of Social Agents of Behavior Change: A Meta-Analysis of the Effectiveness of HIV-Prevention Interventionists for Different Groups

A meta-analysis of 166 HIV-prevention interventions tested theoretical predictions about the effects of experts, lay community members, and similar and dissimilar others, as agents of change. In general, expert interventionists produced greater behavior change than lay community members, and the demographic and behavioral similarity between the interventionist and the recipients facilitated behavioral change. Equally importantly, there were differences across groups in the efficacy of various sources, especially among populations of low status and/or power. These findings support the hypothesis that unempowered populations are more sensitive to characteristics of the interventionists who can facilitate access to various resources. In addition, they suggest the need to ensure the availability of health professionals from diverse demographic and behavioral backgrounds.     

Suicidal ideation and attempts in Norwegian police

Studies on suicide among police show inconsistent results, thereby contributing to considerable speculation regarding why police officers commit suicide. The present paper is the first nationwide study on suicidal ideation and attempts among police. 3,272 Norwegian police completed Paykel's Suicidal Feelings in the General Population questionnaire. Lifetime prevalence of specific questionnaire items ranged from 24% for the feeling that life was not worth living, 6.4% for having seriously considered suicide, and 0.7% for attempted suicide. Independent predictors of serious suicidal ideation were marital status, subjective health complaints, reality weakness, anxiety, and depression. Serious suicidal ideation was mainly attributed to personal and family problems.     

Age differences in implicit memory: conceptual, perceptual, or methodological?

The authors examined age differences in conceptual and perceptual implicit memory via word-fragment completion, word-stem completion, category exemplar generation, picture-fragment identification, and picture naming. Young, middle-aged, and older participants (N = 60) named pictures and words at study. Limited test exposure minimized explicit memory contamination, yielding no reliable age differences and equivalent cross-format effects. In contrast, explicit memory and neuropsychological measures produced significant age differences. In a follow-up experiment, 24 young adults were informed a priori about implicit testing. Their priming was equivalent to the main experiment, showing that test trial time restrictions limit explicit memory strategies. The authors concluded that most implicit memory processes remain stable across adulthood and suggest that explicit contamination be rigorously monitored in aging studies.     

Clinical diagnostic and sociocultural dimensions of deliberate self-harm in Mumbai, India

Patients' accounts complement psychiatric assessment of deliberate self-harm (DSH). In this study we examined psychiatric disorders, and sociocultural and cross-cultural features of DSH. SCID diagnostic interviews and a locally adapted EMIC interview were used to study 196 patients after DSH at a general hospital in Mumbai, India. Major depression was the most common diagnosis (38.8%), followed by substance use disorders (16.8%), but 44.4% of patients did not meet criteria for an enduring Axis-I disorder (no diagnosis, V-code, or adjustment disorder). Psychache arising from patient-identified sociocultural contexts and stressors complements, but does not necessarily fulfill, criteria for explanatory psychiatric disorders.     

Health-related stigma: rethinking concepts and interventions

As a feature of many chronic health problems, stigma contributes to a hidden burden of illness. Health-related stigma is typically characterized by social disqualification of individuals and populations who are identified with particular health problems. Another aspect is characterized by social disqualification targeting other features of a person's identity-such as ethnicity, sexual preferences or socio-economic status-which through limited access to services and other social disadvantages result in adverse effects on health. Health professionals therefore have substantial interests in recognizing and mitigating the impact of stigma as both a feature and a cause of many health problems. Rendering historical concepts of stigma as a discrediting physical attribute obsolete, two generations of Goffman-inspired sociological studies have redefined stigma as a socially discrediting situation of individuals. Based on that formulation and to specify health research interests, a working definition of health-related stigma is proposed. It emphasizes the particular features of target health problems and the role of particular social, cultural and economic settings in developing countries. As a practical matter, it relates to various strategies for intervention, which may focus on controlling or treating target health problems with informed health and social policies, countering the disposition of perpetrators to stigmatize, and supporting those who are stigmatized to limit their vulnerability and strengthen their resilience. Our suggestions for health studies of stigma highlight needs for disease- and culture-specific research that serves the interests of international health.     

Effects of preexposure on stimulus discrimination: an investigation of the mechanisms responsible for human perceptual learning

The effect of preexposure on human perceptual learning was investigated in four experiments. In Experiments 1a and 1b, participants were preexposed to one pair of visual stimuli on an intermixed schedule (AX/BX) and one on a blocked schedule (CX_DX). The ability to discriminate between AX and BX and between CX and DX was then assessed by examining the extent to which key presses assigned to each member of a stimulus pair generalized to the other member (Experiment 1a) and by looking at the accuracy of same-different responses (Experiment 1b). Stimuli were more easily discriminated following intermixed than following blocked preexposure on both the generalization and same-different tasks. This suggests that two stimuli are more perceptually distinct after intermixed preexposure. Experiments 2a and 2b investigated the mechanisms responsible for perceptual learning using same-different tasks. The results support the suggestion that the enhanced discrimination observed after intermixed preexposure is due to increases in the salience of the unique elements.     

Roles of instruments in psychological research

What roles have instruments played in psychology and related disciplines? How have instruments affected the dynamics of psychological research, with what possibilities and limits? What is the psychological instrument? This article provides a conceptual foundation for specific case studies concerning such questions. The discussion begins by challenging widely accepted assumptions about the subject and analyzing the general relations between scientific experimentation and the uses of instruments in psychology. Building on this analysis, a deliberately inclusive definition of what constitutes a psychological instrument is proposed. The discussion then takes up the relation between instrumentation and theories and differentiates in greater detail the roles instruments have had over the course of psychology's history. Finally, the authors offer an approach to evaluating the possibilities and limitations of instruments in psychology.