Two forms, pure-rank and mixed-rank, of a nonparametric, general, linear model-based statistic that can be used to test several hypotheses are presented. A Monte Carlo study was used to investigate the distributional properties of these forms, and their use is discussed. (SLD)

Experimental data on human reasoning in hypothesis-testing tasks is reassessed in light of a Bayesian model of optimal data selection in inductive hypothesis testing. The rational analysis provided by the model suggests that reasoning in such tasks may be rational rather than subject to systematic bias. (SLD)

Tests the hypotheses that overconfidence occurs when strength is high and weight is low and that underconfidence occurs when weight is high and strength is low in 4 experiments with 153 students. Discusses weighing evidence, overconfidence/underconfidence in intuitive judgments, and item difficulty's effect on overconfidence. Relates the…

Presents strengths and limitations of covariance structure analysis (CSA), statistical procedure for testing hypotheses about relations among psychological constructs, as way to test structural hypotheses that are not tested adequately with other statistical procedures. Provides two empirical examples that illustrate use of CSA for evaluating…

A model is presented that demonstrates that a random response to external constraint can produce results similar to those predicted by more complex models. Behavior that appears rational, optimal, or adaptive may truly be a random response to external constraint. Predictions based on this model may provide appropriate null hypotheses. (SLD)

Three articles in this special issue explore issues related to the use and misuse of statistical significance testing, the major methodological issue in current educational research. Comments on these articles and rejoinders by the authors of the first three articles explore additional aspects of statistical significance testing. (SLD)

Although statistical significance testing as the sole basis for result interpretation is a flawed practice, significance tests can be useful as one of three criteria that must be demonstrated to establish a position empirically. Statistical significance testing provides evidence that an event did not happen by chance but gives no evidence of the…

Expresses a "middle-of-the-road" position on statistical significance testing, suggesting that it has its place but that confidence intervals are generally more useful. Identifies 10 errors of omission or commission in the papers reviewed that weaken the positions taken in their discussions. (SLD)

Presents two class activities for use with hypothesis testing in which students collect data to test for a difference in the mean number of chocolate chips per cookie between two brands. (Author/ASK)

The present case continues the series of anomia treatment studies with contextual priming (CP), being the second in-depth treatment study conducted for an individual suffering from semantically based anomia. Our aim was to acquire further evidence of the facilitation and interference effects of the CP treatment on semantic anomia. Based on the…

Offering perspectives in the teaching of statistics assists students, immersed in the study of detail, to see the leading principles of the subject more clearly. Especially helpful can be a perspective on the logic of statistical inductive reasoning. Such a perspective can bring to prominence a broad principle on which both interval estimation and…

Hornworms are good assay organisms for leaf toxins, and can be raised on an artificial medium ("chow"), consisting of corn meal, soy flour, dry milk, yeast and other additives and preservatives. The hornworm assay is less useful in ecological and toxicological research, but is very useful in learning about experimental design and hypothesis…

A Monte Carlo study extended the research of MacKinnon, Lockwood, Hoffman, West, and Sheets (2002) for single-level designs by examining the statistical performance of four methods to test for mediation in a multilevel experimental design. The design studied was a two-group experiment that was replicated across several sites, included a single…

Although most discussions today start from the assumption that the secular rise in IQ must be environmental in origin, three reasons warrant giving the genetic phenomenon heterosis a closer look as a potential cause. First, it easily accounts for both the high heritability and low shared environmental effects seen in IQ, findings that are…

This article provides an overview of the history of research on adolescence. In our view, the history of the scientific study of adolescence has had two overlapping phases and is now on the cusp of a third. The first phase, which began early in the 20th century and lasted about 70 years, was characterized by grand theoretical models that…