The homogeneity assumption in differential prediction analysis: does it really matter?

In simulation studies, the F test for differences in regression slopes has tended to distort nominal Type I and II error rates when the 2 subgroup error variances exceeded a 1.50:1 ratio. This study examines the frequency and extent that this ratio is violated within data sets relevant to applied psychology. The General Aptitude Test Battery (GATB) validity study database contained ability data and overall job performance ratings. The Project A military database contained both ability and personality data, along with job performance factor scores and an overall job performance rating. Results suggest that subgroup (White-Black, male-female) error variances are often homogeneous enough to support F test results from past empirical work. Enough heterogeneity was found, however, to urge applied psychologists investigating differential prediction to explore their data and consider the possibility of alternative statistical tests.     

Disruption of comprehension by the meaning of irrelevant sound

This study investigates the claim that the disruption of comprehension by irrelevant sound is qualitatively different from that of short-term memory for order. Both meaningful and meaningless speech disrupted the comprehensive aspect of the task, but the effect of meaningful speech was significantly greater. Both rehearsal and semantic processing, which are involved in reading comprehension, seem to be susceptible to disruption by irrelevant meaningful speech. The study provides some evidence to suggest that the presence of meaning in the irrelevant sound in creases disruption of performance in cognitive tasks that also call upon processing of meaning.     

The meaning and suitability of various effect sizes for structured Rater x Ratee designs

Four types of analysis are commonly applied to data from structured Rater x Ratee designs. These types are characterized by the unit of analysis, which is either raters or ratees, and by the design used, which is either between-units or within-unit design. The 4 types of analysis are quite different, and therefore they give rise to effect sizes that differ in their substantive interpretations. In most cases, effect sizes based on between-ratee analysis have the least ambiguous meaning and will best serve the aims of meta-analysts and primary researchers. Effect sizes that arise from within-unit designs confound the strength of an effect with its homogeneity. Nonetheless, the authors identify how a range of effect-size types such as these serve the aims of meta-analysis appropriately.     

Detectability of the negative event: effect on the acceptance of pre- or post-event risk-defusing actions

In risky decision situations, many decision makers search for risk-defusing operators (RDOs). An RDO is an action intended by the decision maker to be performed additionally to a specific alternative and is expected to decrease the risk. Pre-event RDOs (e.g., vaccination) have to be applied before a negative event (e.g., infection) occurs. Post-event RDOs do not need to be initiated before and unless the event happens (e.g., medical treatment). For the successful application of Post-event RDOs, the negative event must be detected in time. Two experiments investigated the effect of uncertainty in the detection of the negative event. In Experiment 1, only a small minority of subjects noted this uncertainty without a cue, and even with cue, only a minority actively searched for probability information. In Experiment 2, the probability for correctly detecting the negative event was varied. When detection was certain, most subjects chose the alternative with a Post-event RDO, whereas this percentage decreased significantly with decreasing probability of correct detection. Also, in the conditions with a more extreme negative outcome, less decision makers chose the alternative with the Post-event RDO.     

Anisomycin infused into the hippocampus fails to block "reconsolidation" but impairs extinction: the role of re-exposure duration

Recent studies have reported new evidence consistent with the hypothesis that reactivating a memory by re-exposure to a training context destabilizes the memory and induces "reconsolidation." In the present experiments, rats' memory for inhibitory avoidance (IA) training was tested 6 h (Test 1), 2 d (Test 2), and 6 d (Test 3) after training. On Test 1 the rats were either removed from the shock compartment immediately after entry or retained in the shock context for 200 sec, and intrahippocampal infusions of the protein synthesis inhibitor anisomycin (75 microg/side) were administered immediately after the test. Anisomycin infusions administered after Test 1 impaired IA performance on Test 2 in animals given the brief re-exposure, but impaired extinction in animals exposed to the context for 200 sec. Rats with anisomycin-induced retention impairment on Test 2 demonstrated spontaneous recovery of retention performance on Test 3, whereas rats showing extinction on Test 2 showed further extinction on Test 3. The findings indicate that post-retrieval administration of anisomycin impairs subsequent retention performance only in the absence of extinction and that this impairment is temporary.     

The mini-IPIP scales: tiny-yet-effective measures of the Big Five factors of personality

The Mini-IPIP, a 20-item short form of the 50-item International Personality Item Pool-Five-Factor Model measure (Goldberg, 1999), was developed and validated across five studies. The Mini-IPIP scales, with four items per Big Five trait, had consistent and acceptable internal consistencies across five studies (= at or well above .60), similar coverage of facets as other broad Big Five measures (Study 2), and test-retest correlations that were quite similar to the parent measure across intervals of a few weeks (Study 4) and several months (Study 5). Moreover, the Mini-IPIP scales showed a comparable pattern of convergent, discriminant, and criterion-related validity (Studies 2-5) with other Big Five measures. Collectively, these results indicate that the Mini-IPIP is a psychometrically acceptable and practically useful short measure of the Big Five factors of personality.