Artifactual power curves in forgetting

Recent studies of the mathematical relationship between time and forgetting suggest that it is a power function rather than an exponential function, a finding that has important theoretical consequences. Through computational analysis and reanalyses of published data, we demonstrate that arithmetic averaging of exponential curves can produce an artifactual power curve, particularly when there are large and systematic differences among the slopes of the component curves. A series of simulations showed that the amount of power artifact is small when the slopes of the component curves are normally or rectangularly distributed and when the performance measure is noise free. However, the simulations also showed that the artifact can be quite large, depending on the shape of the noise distribution and restrictions in the performance range. We conclude that claims concerning the form of memory functions should consider whether the data are likely to contain artifact caused by averaging or by the presence of range-restricted noise.     

Convergence in Career Development Theory: A Book Review

Book reviewed in this article: Convergence in Career Development Theory: Implications for Science and Practice by Mark L. Savickas and Robert W. Lent (Eds.)     

Different WAIS-R short forms and their relation to ethnicity

Potential racial bias on commonly used WAIS-R short forms was examined in a group of 201 African-Americans matched with Caucasians in terms of age, education, gender, and occupational status. Within racial groups, all short form IQs correlated highly with the WAIS-R IQs (all rs 0.87). Although relatively large racial differences emerged on the Block Design, Vocabulary, and Arithmetic subtests, only mild racial discrepancies emerged for three out of the seven short forms investigated. While the magnitude of the results for the short forms was mild, based on these findings it was suggested that certain short forms not be used with African-Americans in order to minimize the potential influence of racial basis.     

Perception of object unity in chicks: A comparison with the human infant

Newly hatched chicks (Gallus gallus) were imprinted on a display consisting of two rod pieces that moved above and below a central occluder. On test trials, the chicks approached a complete rod in preference to two rod pieces. This finding, supported by those from control coditions, suggests that chicks, soon after hatching, perceive object unity. The results are compared with those from human infants.     

Effects of Nonlinearity and Heteroscedasticity on the Validity of Conscientiousness in Predicting Overall Job Performance

Most research on the relationship between personality and overall job performance assumes linearity and homoscedasticity. This study investigated the prevalence and nature of nonlinearities and heteroscedasticies in relationships between conscientiousness and supervisory ratings of overall job performance across five independent samples using both concurrent (k = 4) and predictive (k = 1) designs. Hierarchical polynomial regression analyses found evidence of robust linear effects but no evidence of statistically significant quadratic or cubic effects. A statistically and practically significant heteroscedastic effect was found in only one sample such that lower errors of prediction were evidenced in the ends in comparison to the middle of the bivariate distribution. Implications for the use of conscientiousness in personnel selection are suggested. Limitations of the current study and directions for future research are noted.     

A Test of the Contingency Model of Leadership Effectiveness1

Randomly formed groups of 160 male students a t St. Francis Xavier University performed both a structured and an unstructured task. Style of leadership and leader position power were experimentally manipulated, while leader member relations were held constant. Although manipulation checks were positive, results failed to support any of the hypotheses derived from Fiedler's contingency theory of leadership effectiveness.     

Observer recorder error as affected by different tasks and different expectancy inducements

Four experiments were designed to investigate the effects of systematic observer/recorder error on experimental results where experimenters had been induced to expect certain results. In the first experiment, experimenters were induced to expect certain outcomes for three different tasks. No observer error nor experimenter-effects were observed. Postexperimental interviews indicated some suspiciousness as well as failure to understand the hypotheses on the part of experimenters. In the second experiment expectancies were induced in observers who did not act as experimenters. No observer effects were noted, and again postexperimental interviews indicated manipulation failure. In the third experiment experimenters were asked to attempt to influence subjects' responses. Three tasks were used, but in two of these tasks observer error was controlled rather than measured. No differences in subjects' responses were noted for any of the measures. However, significant observer/recorder error was noted for both male and female experimenters in the task where such error was measurable. In the fourth experiment experimenters were again asked to influence subjects' responses. For the two tasks used observer error was measured. A predicted Task × Observer Error Interaction was obtained. Again, no differences in subjects' responses were noted.     

Motivated remembering efforts during tip-of-the-tongue states

Hart (1965) argues that the feeling of knowing in tip-of-the-tongue (TOT) states monitors memory content and motivates retreival efforts. Although a number of studies have examined the memory-monitoring accuracy of feelings of knowing and not-knowing, no studies have focused directly on the hypothesized motivational function of these feeling states. This second function of memory feeling states is investigated in this study by assessing the degree to which TOT and Don't Know (DK) states interfere with a subject's ability to perform well on a concurrent task. Subjects studied a list of arbitrary word pairs for 3, 5, or 7 seconds and then provided Recall, TOT, or DK reports in an immediate recall test. Performance on the simple number-probe task that followed each memory report was poorer on TOT trials than on DK trials. This effect did not vary as a function of encoding time. Since covert memory searches were possible on both TOT and DK trials, it is concluded that the performance decrement observed on TOT trials is due to the fact that covert TOT target searches command processing capacity that might otherwise go to the concurrent number-probe task. The absence of an encoding time effect suggests that TOT states do not monitor the associative strength of target traces as Hart (1967) has proposed. The findings in this study are interpreted as providing support for the proposition that the feeling of knowing in the TOT state influences the setting of capacity-allocation priorities in the memory system.