This study examined interrelationships among combat exposure, symptoms of posttraumatic stress disorder (PTSD), and family adjustment in a sample of male and female Operation Desert Storm veterans (N = 1,512). In structural equation models for both male and female veterans, higher combat exposure was associated with higher PTSD symptoms, which in…

This study investigated whether pre-task planning that embeds grammatical guidance to attend to a specific L2 form might be a suitable pedagogical choice in beginning-level foreign language classrooms. First-year high school students of English in Japan were asked to do an oral story-retelling task with a class partner under one of three…

The sampling distribution is a common source of misuse and misunderstanding in the study of statistics. The sampling distribution, underlying distribution, and the Central Limit Theorem are all interconnected in defining and explaining the proper use of the sampling distribution of various statistics. The sampling distribution of a statistic is…

Considered in this paper are a mathematical discussion and an algorithm, and a computer program for Fisher's test. (Author)

Examines the question of how large a sample must be in order to produce empirical Bayes estimates which are preferable to other commonly used estimates, such as proportion correct observed score. (Author/RC)

A procedure for testing heterogeneity of variance is developed which generalizes readily to complex, multi-factor experimental designs. Monte Carlo studies indicate that the Z-variance test statistic presented here yields results equivalent to other familiar tests for heterogeneity of variance in simple one-way designs where comparisons are…

As significance testing comes under increasing criticism, some researchers are turning to other indices to evaluate their findings. Included among the alternative options are the interpretation of effect size estimates and the evaluation of sample specificity (invariance testing). Using a hypothetical data set of 64 cases and two predictor…

Too often researchers rely upon the classical normal theory parametric tests to analyze non-normal data, even though the tests may not be robust to violations of that assumption. Fligner's class of two-sample tests for scale is an important development because the test is distribution-free and has desirable properties. This paper outlines the…

A new test for increasing or decreasing trend in a set of observations is presented. Rather than making specific paired comparisons, as in the Cox and Stuart tests for trend, the user of the new test makes the comparisons of all possible pairs of observations. (Author)

TO TEST THE ASSUMPTION THAT LEARNING EFFECTIVENESS VIA TV MIGHT DECLINE DUE TO LENGTHY VIEWING TIME AND FATIGUE, THIS STUDY COMPARED EFFECTS OF 38 HOURS OF CONTINUOUS TV TRAINING IN 5 DAYS WITH REGULAR CLASSROOM INSTRUCTION OVER THE SAME PERIOD. EFFECTIVENESS OF THE MINIMAL TV PRESENTATIONS THAT TRANSMIT EXISTING CLASSROOM INSTRUCTION WITH NO…

Researchers often use the analysis of variance to test hypotheses about the means, followed by a multiple comparison technique when the F-test is significant. The technique is this study was developed by Newman (1939) and Keuls (1952). A flaw in the rationale underlying this technique was evaluated to determine whether the flaw is sufficiently…

This study shows that the test statistic for Analysis of Covariance (ANCOVA) has a noncentral F-districution with noncentrality parameter equal to zero if and only if the regression planes are homogeneous and/or the vector of overall covariate means is the null vector. The effect of heterogeneous regression slope parameters is to either increase…

The purposes of this study were to tabulate the exact cumulative probabilities for a multinomial such that expected frequencies vary from 1 to not less than 5 in the case where the expected frequencies are equal and to study the accuracy of the conventional chi-square goodness-of-fit test. The tables of cumulative probabilities provide exact tests…