This paper outlines the problems associated with the estimation of variance components in generalizability analyses using analysis of variance software, and discusses the most useful software currently available for this specialist application: the MIVQUE method of the Statistical Analysis System (SAS) procedure VARCOMP. (Author)

Khuri's and Satterthwaite's methods of obtaining confidence intervals of variance components are compared. The article discusses that Khuri's method may be applied to obtain confidence intervals for the variance components and other linear functions of the expected mean squares used in generalizability theory. (Author/JAZ)

A methodology is presented for minimizing mean error variance in generalizability studies when resource constraints are imposed. The optimal number of observations and conditions of facets for random model, fully crossed one- and two-facet designs can be decided. Parallel closed form formulas can be determined for other designs. (SLD)

This commentary focuses on the application of D. Rogosa and G. Ghandour's work to observational research on classroom processes. Rogosa and Ghandour have shown that the short length of an observation is typically the dominant source of error. Investigators should conduct observations for as long as possible. (SLD)

The monograph by D. Rogosa and G. Ghandour represents a body of cohesive and comprehensive research that can be the basis of a new measurement theory combining features of generalizability theory and strong true-score theory. Principles, approaches, arguments, and conclusions are reviewed; and critical comments are offered. (SLD)

Issues raised with the statistical models developed are discussed point by point, restating the emphasis on finite observation time, and reiterating the criticism of traditional psychometric methods. It is noted that the language and technical formulation of psychometrics can be extremely awkward in dealing with biased estimates. (SLD)

Natural statistical models based on renewal processes for individuals' Behavior Stream are developed. For continuous observation, statistical and psychometric properties are obtained for empirical: (1) rates of behavior; (2) proportions of behavior type; (3) prevalence; and (4) event duration. Results provide a guide for design and analysis. (SLD)