Prior research indicates that the overall reliability of performance ratings can be improved by using ordinary least squares (OLS) regression to adjust for rater effects. The present investigation extends previous work by evaluating the impact of OLS adjustment on standard errors of measurement ("SEM") at specific score levels. In…

Developed a procedure for overcoming the computational and technological limitations of analyzing data with missing observations by extracting data from a sparsely filled data matrix into analyzable smaller subsets of data. Demonstrated the validity of this subdividing method using a Monte Carlo simulation. (SLD)

Provides a comprehensive and integrated treatment of both conditional absolute standard errors of measurement (SEM) and conditional relative SEMs from the perspective of generalizability theory. Illustrates the approach with examples from commercial standardized tests. Examples support the conclusion that both types of conditional SEMs tend to be…

Reviews relevant aspects of generalizability theory related to performance assessments and discusses the role of various facets in assessing the generalizability of performance assessments. Also considers some popular estimates of reliability for performance assessments from the perspective of generalizability theory. (SLD)

In assessment programs where scores are reported for individual examinees, it is desirable to have responses to performance exercises graded by more than one rater. If more than one item on each test form is so graded, it is also desirable that different raters grade the responses of any one examinee. This gives rise to sampling designs in which…

The extent to which a scale score generalizes to a latent variable common to all of the scale's indicators is indexed by the scale's general factor saturation. Seven techniques for estimating this parameter--omega[hierarchical] (omega[subscript h])--are compared in a series of simulated data sets. Primary comparisons were based on 160 artificial…

Introduces the articles of this theme issue focusing on performance assessment methodology. Papers address: (1) merging item formats; (2) scoring models; (3) equating and linking; (4) generalizability theory; (5) standard setting methods; and (6) validity issues and methods. (SLD)

Simulations demonstrate the effects of correlated errors on the person-by-occasion design in which the confounding effect of equal time intervals results in correlated error terms in the linear model. Two specific error correlation structures were examined. Conditions under which underestimation and overestimation occur are discussed. (SLD)

The implications of serially correlated effects on the results of generalizability analyses are discussed. Simulated data are provided that demonstrate the biases that serially correlated effects introduce into the results. Serial correlation in measurement effects can have a marked influence on the impression of the dependability of measurement…