Some of the more simplified methods for contrasts with equal sample sizes in multiple regression analysis are shown to result in erroneous calculations when applied to data sets with unequal sample sizes. An alternative method is provided. (Author/JKS)

The importance of measuring the size of an effect for fixed effects factorial analysis of variance designs is emphasized. Technical issues in such measurement are considered and examples are provided. (Author/JKS)

A method is proposed for overcoming the problem of multicollinearity in multiple regression equations where multiplicative independent terms are entered. The method is not a ridge regression solution. (JKS)

Twenty-six subjects were exposed to a period of noxious stimulation and subsequently performed a task that incidentally involved learning to avoid one of two types of punishment, electric shock and monetary loss. Results support Lykken's theory of the development of sociopathic behavior and Aronfreed's more general conceptualization of aversive…

Fifty-one psychiatric inpatients were tested on a 36-item satisfaction scale before and after and after a reorganization at Harlem Valley Psychiatric Center. Results showed that the involuntary relocation of chronic psychiatric patients to another institutional treatment environment causes few demonstrable effects. (Editor/RK)

This research examines separately the cognitive and pharmacological effects of alcohol by manipulating subjects' expectancies. It was found that although alcohol is a pharmacologic sedative and reduces anxiety, the cognition that one is drinking alcohol increases anxiety. (Editor/RK)

Some common reasons for failures of experimental procedures are presented and suggestions are given for avoiding them through systematic precautions taken beforehand. (Editor)

Piaget has stated that the child's active manipulation of objects is a necessary part of teaching for intellectual development. But this appears to be contrary to empirical evidence. From a review of literature, it is concluded that Piaget's insistence on physical activity, and his dismissal of observation, are excessive. (Editor)

The hypotheses of informational cognitive control, based on the idea that being able to predict the occurrence of an unpleasant event facilitates a reduction of its impact, has not received clear support in previous research. This experiment investigates the effects of three variables on subjective reactions to mild electric shock. (Editor/RK)

Most studies of memory emphasize the direct encoding of physical stimuli. In contrast, this research investigates memory for the internal stimuli that are generated during processing of a presented stimulus. (Editor)

Suggests that early in their education students be taught to use basic statistical tests as rigorous methods of comparing experimental results with scientific hypotheses. Stresses that students learn how to use statistical tests in hypothesis-testing by applying them in actual hypothesis-testing situations. To illustrate, uses questions such as…

Two possible standard error formulas for the polytomous differential item functioning index proposed by N. J. Dorans and A. P. Schmitt (1991) were derived. These standard errors, and associated hypothesis-testing procedures, were evaluated through simulated data. The standard error that performed better is based on N. Mantel's (1963)…

How log-linear models for multiwave longitudinal data can be used to test hypotheses relating to stagelike relationships between variables is demonstrated using data from research on adolescent cigarette and marijuana experimentation. Results with 2,658 adolescents show that the multiwave analyses allow the testing of several hypotheses. (SLD)

Developed and investigated a goodness-of-fit statistic that considers the uncertainty with which ability is estimated and a resampling-based hypothesis testing procedure. Simulation study results indicate that the procedure should be useful for evaluating goodness-of-fit item response theory models for most testing applications when uncertainty in…

Proposes a conceptual framework for analyzing students' knowledge of programming. The idea is to integrate three types of programming knowledge from educational computing literature with three forms of knowledge from cognitive psychology literature. A study is described that determined types of knowledge required to answer exam questions, and…