Using Microsoft® Excel, several interactive, computerized learning modules are developed to illustrate the Central Limit Theorem's appropriateness for comparing the difference between the means of any two populations. These modules are used in the classroom to enhance the comprehension of this theorem as well as the concepts that provide the…

The meta-analysis of coefficient alpha across many studies is becoming more common in psychology by a methodology labeled reliability generalization. Existing reliability generalization studies have not used the sampling distribution of coefficient alpha for precision weighting and other common meta-analytic procedures. A framework is provided for…

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…

Grouping is a statistical procedure through which members of the same group are considered as a single unit of observation. There are various ways to assign group membership and various ways to assign values of variables to groups. There are methodological problems associated with grouping in general and with particular methods of grouping. This…

An alternative derivation of Tryon's basic formula for the coefficient of domain validity or the coefficient of generalizability developed by Cronbach, Rajaratnam, and Glaser is provided. This derivation, which is also the generalized Kuder-Richardson coefficient, requires a relatively minimal number of assumptions compared with that in previously…

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…

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…

This paper is a primer on sampling procedures for statewide assessment. The careful reader should gain substantial knowledge about the promises and pitfalls of sampling for assessment. The primer has three basic objectives: (1) to define terms and concepts basic to sampling theory and its application, including population, sampling unit, sampling…

This study investigated the effects of non-normality of the marginal distributions of the bivariate surface upon the sampling distribution of certain tests of significance of differences for the product moment correlation coefficient. The effects of non-normality were found to be rather substantial and to be dependent upon: 1) the degree of…

This study employed standard sampling theory to make a study of library book losses, but unlike previously reported studies, the investigators instituted periodic searches for volumes missing after the original search. Over a period of two years and nine months, the original figures were cut by more than 60 percent. (Author)

The weighted kappa coefficient is a measure of interrater agreement when the relative seriousness of each possible disagreement can be quantified. This monte carlo study demonstrates the utility of the kappa coefficient for ordinal data. Sample size is also briefly discussed. (Author/JKS)