Kelly's formula estimates sampling variance of correlation corrected for attenuation by using split-half reliabilities. In some cases, coefficient alpha estimate of reliability is preferable. A simulation study suggests a variation of Kelly's formula can be used appropriately with coefficient alpha. Kelly's formula is modified to accept…

Monte Carlo methods are used to explore the accuracy of a method for establishing confidence intervals for variance component estimates in generalizability studies. Previous research has shown that variance component estimation errors due to sampling are often larger than suspected. (Author/CM)

Some procedures for estimating internal consistency reliability may be superior mathematically to the more commonly used methods such as Coefficient Alpha. One problem is computational difficulty; the other is the possibility of overestimation due to capitalization on chance. (Author/CTM)

Some statistical considerations in applying survey sampling methods to small populations are explored. (DS)

This paper presents the generalized symmetric means approach to the estimation of population covariances, complete with derivations and examples. Particular attention is paid to the problem of missing data, which is handled very naturally in the incidence sampling framework. (CTM)

Two independent replications of a sequence of simulations were conducted to aid in the diagnosis and interpretation of equating differences found between representative (random) and matched (nonrandom) samples for three commonly used conventional observed-score equating procedures and one item-response-theory-based equating procedure. (SLD)

Explores how to achieve rigor in applying methodology to research questions regarding quantitative approaches, specifically regarding statistical analysis, measurement, and sample decisions. (SR)

Sampling error refers to variability that is unique to the sample. If the sample is the entire population, then there is no sampling error. A related point is that sampling error is a function of sample size, as a hypothetical example illustrates. As the sample statistics more and more closely approximate the population parameters, the sampling…

The position of the "purists" who insist on limiting data to ordinal analysis is contrasted with the "pragmatists" who treat data as interval. (Author)

Monte Carlo methods were used to investigate the robustness of techniques used in judging the magnitude of a sample correlation coefficient when observations are correlated. Empirical distributions of r, t, and Fisher's z were generated. A technique for controlling error rates in certain situations is suggested. (Author/BJG)

Major interest is the derivation of a mathematical formulation and a demonstration of the effects of pooling two subgroups on the total group correlation coefficient, and additionally, a procedure to guide the decision concerning the pooling of data for the purpose of calculating a single correlation coefficient. (Author/RC)

A method of applying the discriminant function to correlated samples was discussed for the researcher interested in utilizing multivariate statistics to pre-post data. By finding the linear combination that maximizes differences in the groups, the t-statistic can be computed for correlated samples. (Author)

Investigated empirically through post mortem item-examinee sampling was the feasibility of the jackknife as a procedure for approximating standard errors of estimate in multiple matrix sampling. The parameters estimated were the mean test score, second through fourth central moments of the test score distribution, and the variance of the item…

The power of a statistical test is, in part, a function of the reliability of the dependable variable being analyzed. The substitution of sigma square divided by the reliability coefficient for sigma is proposed. This enables the researcher to incorporate dependent variable reliability information when determining the sample size required for a…