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)

The biases and mean squared errors of the sample squared multiple correlation coefficient and five adjusted estimators of the population squared multiple correlation are examined. A quadratic estimator and the minimum variance unbiased estimator are also examined. These estimators are compared in terms of absolute bias and mean squared error.…

In a study of a managerial training program, two subsamples of co-workers (supervisors and subordinates) were used to validate the participants' assessments of program impact. Use of subsamples provided support in direction and magnitude of the participants' assessments and generally strengthened the validity of the findings. (TJH)

An algorithm and associated FORTRAN-77 computer subroutine are described for computing Goodman and Kruskal's tau-b statistic along with the associated nonasymptotic probability value under the null hypothesis tau=O. (Author)

Presents a statistical technique that yields consistent estimates for censored samples. Application of this technique to models related to selection bias and the presence of depression indicate that the prevalence of this disorder in mental health center populations approaches 44 percent rather than the 25 percent from a censored sample.…

By using the procedure presented in this article, instructional developers will be able to make supportable decisions about their material without going through a complex statistical exercise and, perhaps, without having a large sample size. (Author/ER)

We distinguish two conceptions of sample and sampling that emerged in the context of a teaching experiment conducted in a high school statistics class. In one conception "sample as a quasi-proportional, small-scale version of the population" is the encompassing image. This conception entails images of repeating the sampling process and…

Theoretical hypotheses generated from data analysis of a single sample should not be advanced until the replicability issue is treated. At least one of three questions usually arises when evaluating the invariance of results obtained from a canonical correlation analysis (CCA): (1) "Will an effect occur in subsequent studies?"; (2)…

The meaningful investigation of many problems in statistics can be solved through Monte Carlo methods. Monte Carlo studies can help solve problems that are mathematically intractable through the analysis of random samples from populations whose characteristics are known to the researcher. Using Monte Carlo simulation, the values of a statistic are…

Eta-Squared (ES) is often used as a measure of strength of association of an effect, a measure often associated with effect size. It is also considered the proportion of total variance accounted for by an independent variable. It is simple to compute and interpret. However, it has one critical weakness cited by several authors (C. Huberty, 1994;…

The primary objective of this study was to investigate how incorporating prior information improves estimation of item parameters in two small samples. The factors that were investigated were sample size and the type of prior information. To investigate the accuracy with which item parameters in the Law School Admission Test (LSAT) are estimated,…