Knowledge that Transforms

Subliminal self-help audiotapes to aid weight loss were evaluated to determine if their apparent effectiveness is due to a placebo effect. All subjects were female students or staff who were both overweight and believed in the possible effectiveness of subliminal audiotapes. Three different groups of subjects were tested: One group listened to subliminal audiotapes purchased directly from a manufacturer, the 2nd group listened to comparable placebo tapes, and the 3rd group did not listen to any tapes at all. Each subject in each group was weighed once each week for 5 weeks. All 3 groups of subjects lost weight, and the average amount of weight lost by each group was approximately equivalent. These results provide no evidence that regular use of subliminal audiotapes leads to a placebo effect. Rather, the results suggest that regular use of subliminal audiotapes may simply make subjects more conscious of their weight.

To evaluate whether antianxiety drugs enable guilty subjects to appear innocent on polygraph tests, we compared the effects of diazepam, meprobamate, and propranolol on the outcome of a guilty knowledge test (GKT). Seventy-five undergraduate students were evenly divided among one innocent and four guilty groups. Subjects in each of the guilty groups received either one of the drugs or a placebo prior to the administration of the GKT and after viewing a videotape that depicted a burglary as seen from the perspective of the burglar. The results showed that drug status had no influence on the outcome of the GKT. Innocent subjects who coincidentally obtained high scores on a recognition memory test covering details of the mock crime tended to obtain higher guilt scores on the GKT.

We respond to the points made by Cropanzano and James (1990) concerning the article by Arvey, Bouchard, Segal and Abraham (1989). We acknowledge that the Arvey et al. (1989) study is based on a single design, makes use of a small and special sample, and, as such, is vulnerable to threats of internal and external validity. Nevertheless, after providing a more comprehensive conceptual and empirical context for the study, and after reviewing a number of issues raised by Cropanzano and James, we conclude that it is not premature to accept the idea that work attitudes are partially genetically influenced.

A modification of Brogden's (1949) utility formula is proposed for establishing optimal cutoff scores in criterion-related validity studies. The proposed modification highlights the direct trade-off between selecting more capable applicants and the costs associated with selection and recruiting. Data from national cost-per-hire surveys are presented to illustrate the magnitude of recruting costs relative to selection costs. In addition, an analysis of recruiting practices suggests the need to account for variable recruiting costs when establishing cutoff scores.

This study examined the equivalence of constructs underlying scores on tests designed to measure the knowledge, skills, and abilities required by specific jobs with the constructs underlying scores on aptitude tests taken from published test batteries. Several models of construct equivalence, differing in their assumptions about factor patterns, factor loadings, and variable uniquenesses, were assessed with confirmatory factor analysis. Results indicated that the job-specific tests measured constructs that were essentially equivalent with the constructs measured by the commercially available tests, although the magnitude of unique residual variances differed among the two sets of tests. Furthermore, multiple-groups confirmatory factor analysis indicated that tests loaded equivalently on shared constructs across several sex and race subgroups, although unique residual variances differed across groups. Practical and theoretical implications are discussed. Choices of predictor measures in personnel selection contexts typically require decisions regarding whether tests of general aptitudes relevant to success across diverse jobs, or tests designed to measure the specific knowledge, skills, and abilities (KSAs) needed to perform the jobs of interest, should be used. Tests of the former type are commercially available and may be cost effective in the short term. Moreover, substantial meta-analytic evidence suggests that general aptitude tests predict success across a wide variety of jobs (Ghiselli, 1966,1973; Hunter & Hunter, 1984). General aptitude tests can be criticized, however, for containing items that have no apparent relevance to success for any particular job (Kleiman & Faley, 1985). Determination of the desired predictors for a job requires that the user base his or her decisions on some logical, empirical, or theoretical foundation (Society for Industrial and Organizational Psychology, 1987). Hence, general aptitude tests may come under particularly close scrutiny if a rationale for their choice has not been made explicit (Kleiman & Faley, 1985). Defending the use