For a test that consists of dichotomously scored items, several approaches have been reported in the literature for estimating classification consistency and accuracy indices based on a single administration of a test. Classification consistency and accuracy have not been studied much, however, for "complex" assessments--for example,…

Reviews important milestones in the history of reliability, current issues related to reliability, and likely prospects for reliability from the perspective of what constitutes a replication of a measurement procedure. Pays special attention to the fixed/random aspects of facets that characterize replications. (SLD)

The use of educational tests in practical situations often requires that tests that are built to different content and/or statistical specifications be statistically linked. When equating methods are applied to tests that differ in content, difficulty, and/or reliability, the resulting scores cannot be used interchangeably. This study examined…

Not infrequently, investigators assume that reliability for groups is greater than reliability for persons, or that the error variance for groups is less than that for persons. Using generalizability theory, it is shown that this "conventional wisdom" is not necessarily true. Examples are provided from the course-evaluation and the…

A conceptual framework and heuristic model for considering the existence, magnitude, and consequences of context effects are presented through an extension of some generalizability theory concepts. Context effects are often misunderstood, and current measurement models have serious limitations for examining them. Their importance needs to be…

Discusses some problems, pitfalls, and paradoxes that challenge measurement theory and practice, especially for K-12 achievement testing. Considers a number of technical issues, especially some related to reliability. Also discusses a number of practical or political issues related to validation and accountability. (SLD)

When classes are the units of analyses, estimates of the reliability of class means are needed. Using classical test theory it is difficult to treat this problem adequately. Generalizability theory, however, provides a natural framework for dealing with the problem. Each of four possible formulas for the generalizability of class means is derived…

The framework and procedures of generalizability theory are introduced and illustrated in this instructional module that uses a hypothetical scenario involving writing proficiency. Generalizability analyses are useful for understanding the relative importance of various sources of error and for designing efficient measurement procedures. (SLD)

A review of four areas in which the computer has influenced the theory and practice of achievement testing: a) test scoring and item analysis, b) item sampling, c) item generation, and d) the sequencing of items resulting in various types of adaptive testing. Also, reference is made to the impact of computer assisted achievement testing upon the…

Rules, procedures, and algorithms intended to aid researchers and practitioners in the application of generalizability theory to a broad range of measurement problems are presented. Two examples of measurement research are G studies, which examine the dependability of some general measurement procedure; and D studies, which provide the data for…

Explores the relationship between measurement theory and practice, considering five broad categories of: (1) models, assumptions, and terminology; (2) reliability; (3) validity; (4) scaling; and (5) setting performance standards. It must be recognized that measurement is not an end in itself. (SLD)