On the basis of a review of the literature and the results of three experiments with dog experts, Robbins and McKone [Robbins, R. A., & McKone, E. (2006). No face-like processing for objects-of-expertise in three behavioural tasks, "Cognition"] argue that there is little or no evidence supporting an expertise account of the differences in…

The authors tested hypotheses concerning personality differences in treatment-seeking suicide attempters (AT; n = 60) and a community sample of suicides (SU; n = 43) over age 50. On the basis of prior research, the authors hypothesized that SU would be lower in Neuroticism and Openness and higher in Conscientiousness. A 2-group (AT vs. SU)…

This educational software was developed to aid teachers and students in their understanding of how the process of identifying the most likely quantitative trait loci (QTL) position is determined between two flanking DNA markers. The objective of the software that we developed was to: (1) show how a QTL is mapped to a position on a chromosome using…

Methods for the analysis of within-subjects effects in multivariate groups by trials repeated measures designs are considered in the presence of heteroscedasticity of the group variance-covariance matrices and multivariate nonnormality. Under a doubly multivariate model approach to hypothesis testing, within-subjects main and interaction effect…

A selection of statistical problems commonly encountered in psychological or psychiatric research concerning correlation coefficients are re-evaluated in the light of recently developed simplifications in the forms of the distribution theory of the intraclass correlation coefficient, of the product-moment correlation coefficient, and the Spearman…

Two experiments examined the hypothesis that the average of group members' responses following group discussion will generally be more extreme in the same direction as the average of individual pregroup preferences. (Author/MLF)

In analyzing exploratory repeated measures data with more than two measures, two competing tests must be administered simultaneously if one is to make an efficient and effective decision regarding the tenability of the null hypothesis of no differences among measurement means. Obviously, such a procedure is not without a cost vis-a-vis Type I…

A set of general principles underlying theory formation, theory revision, and experimentation are described. The manner in which these techniques may be integrated to provide a unified and comprehensive treatment of scientific theory development is demonstrated. In particular, the means by which experimentation is used to empirically guide and…

Twenty Monte Carlo studies on multiple comparison (MC) techniques were conducted to examine which MC technique was the "method of choice." The results from these studies had several apparent contradictions when different techniques were investigated under varying sample size and variance conditions. Box's coefficient of variance…

See TM 501 201-3 and EJ 060 883 for related articles. (MLP)

A total of 28 children were tested for comprehension of spatial antonym pairs with arrays which contained four objects representing both members of two antonym pairs. The results supported a modified semantic-feature hypothesis, in which polarity is acquired before dimension. (Author/LLK)

The controversy regarding the admissibility of one-tailed tests of hypotheses was examined. Rather than taking a stand with regard to whether the one-or the two-tailed test is the most seriously flawed, a procedure is developed which can capitalize on the advantages of each. (RC)

Power and stability of Type I error rates are investigated for the Bartlett and Kendall test of homogeneity of variance with varying subsample sizes under conditions of normality and nonnormality. The test is shown to be robust to violations of the assumption of normality when sampling is from a leptokurtic population. Suggestions for selecting…

The Integrated Moving Average (IMA) model of time series, and the analysis of intervention effects based on it, assume random shocks which are normally distributed. To determine the robustness of the analysis to violations of this assumption, empirical sampling methods were employed. Samples were generated from three populations; normal,…

An empirical sampling study investigated six procedures for testing differences between means in the presence of unequal n's and variances. Support was obtained for previous research which found t robust to heterogeneous variances only when n's are equal and of moderate size. The procedure which emerged as providing the best control over Type I…