A paradoxical phenomenon of decreases in reliability as the number of elements averaged over increases is shown to be possible in multifacet reliability procedures (intraclass correlations or generalizability coefficients). Conditions governing this phenomenon are presented along with implications and cautions. (Author)

Studied the effects of items, passages, contents, themes, and types of passages on the reliability and standard errors of measurement for complex reading comprehension tests using seven different generalizability theory models. Results suggest that passages and themes should be taken into account when evaluating the reliability of test scores for…

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)

Studied the appropriateness and implications of incorporating a testlet definition into the estimation of procedures of the conditional standard error of measurement (SEM) for tests composed of testlets. Simulation results for several methods show that an item-based method using a generalizability theory model provided good estimates of the…

In this case study, the progression of racial identity development (RID) is described in two individuals. The study was designed to describe nonclinical experiences of being biracial, explore how Black identity has different meaning for biracial people, and distinguish between Black RID and biracial RID. Raises questions about the generalizability…

This study examined the generalizability of systematic direct observation across setting and time. Participants included 14 students from an intact inclusionary fifth grade classroom. On-task/off-task behavior was directly observed using momentary time-sampling recording, twice a day, for 10 school days. Using Generalizability (G) theory, results…

This article considers and illustrates a strategy to study effects of school context on differential item functioning (DIF) in large-scale assessment. The approach employs a hierarchical generalized linear modeling framework to (a) detect DIF, and (b) identify school-level correlates of the between-group differences in item performance. To…

The authors used cross-cultural methodology to examine the demand-withdraw pattern of marital communication. In Western countries, women usually make more demands, whereas men are more likely to withdraw. But the recently advanced marital structure hypothesis suggests that this pattern can be altered by gender roles and beliefs, particularly in…

Applied psychologists who provide services in nations composed of multiple and varied cultural groups face certain ethical dilemmas that would not arise in more homogeneous societies. These ethical dilemmas revolve around the concept of population validity. Population validity refers to the generalizability of research findings across different…

Three procedures for evaluating the sampling specificity of results are reviewed. These procedures are Tukey's jacknife technique, Efron's bootstrap technique, and cross-validation methods. The jacknife technique uses different subsamples derived from the original total data set to provide empirical estimates of the generalizability of effect…

A procedure was developed to analyze data with missing observations by extracting data from a sparsely filled data matrix into analyzable smaller subsets of data. This subdividing method, based on the conceptual framework of meta-analysis, was accomplished by creating data sets that exhibit structural designs and then pooling variance components…

The purpose of this study was to investigate the relative appropriateness of several procedures for estimating reliability and standard errors of measurement of complex reading comprehension tests. Seven generalizability theory models were conceptualized by incorporating one or several factors of items, passages, themes, contents, and types of…

Generalizabilty theory was used to examine the dependability of anchoring labels of Likert-type scales. In samples of 173 graduate students and 108 graduate students completing attitude measures, variance components associated with labeling were found to be minute, contributing little to observed score variance. Possible explanations are…

This book presents a comprehensive overview of univariate and multivariate generalizability theory, a psychometric model that provides a powerful approach to the analysis of errors of measurement through the use of random-effects and mixed-model analysis of variance. (SLD)