Intraclass correlation coefficients (ICCs) are commonly used in behavioral measurement and psychometrics when a researcher is interested in the relationship among variables of a common class. The formulas for deriving ICCs, or generalizability coefficients, vary depending on which models are specified. This article gives the equations for…

Generalizability theory is described as a way to provide a unified framework for examining the dependability of measurements in the health sciences. Generalizability theory is appropriate whether the measurement is norm- or criterion-referenced, an individual or aggregate-level variable, and it is useful when there are single or multiple sources…

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…

Research on developing technology for large-scale performance assessments in science is reported briefly, and a conceptual framework is presented for defining, generating, and evaluating science performance assessments. Types of tasks are discussed, and the technical qualities of performance assessments are discussed in the context of…

Presents a model-based approach to rater reliability for essays read by multiple raters. The approach is motivated by generalizability theory, and variation of rater severity and rater inconsistency is considered in the presence of between-examinee variations. Illustrates methods with data from standardized educational tests. (Author/SLD)