A study of item response theory in language testing research investigated the influence of sample size on (1) the statistical test of data-model fit and (2) the invariance of parameter estimates. Data were drawn from a 1993 administration of the examination of Dutch as a second language to about a thousand candidates, using results from only the…

This report describes and evaluates the major computer software packages capable of computing standard errors for statistics estimated from complex samples. It first describes the problem and the proposed solutions. The two major programs presently available, SUPER CARP and OSIRIS, are described in general terms. The kinds of statistics available…

In addition to the usual problems of obtaining a representative sample, the family researcher is confronted with the problem of who speaks for the family. Traditionally women have been the informants in family research. To examine the coparental relationship between divorced spouses, data were collected from both former spouses (N=98 couples). 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…

The school district fiscal capacity data (1962 and 1967) of the National Finance Project were analyzed for psychometric adequacy and robustness of component composition. The procedures involved: (1) the computation of the Kaiser, Meyer, Olkin Measure of Sampling Adequacy, (2) inspection of the off-diagonal elements of the antiimage covariance…

This paper examines issues related to the statistical power of impact estimates for experimental evaluations of education programs. The focus is on "group-based" experimental designs, because many studies of education programs involve random assignment at the group level (for example, at the school or classroom level) rather than at the student…

This paper offers recommendations to the National Center for Education Statistics (NCES) on the development of the background questionnaire for the National Assessment of Adult Literacy (NAAL). The recommendations are from the viewpoint of a researcher interested in applying sophisticated statistical models to address important issues in adult…

The National Assessment of Educational Progress (NAEP) measures the educational achievement of nationally representative samples of students in grades 4, 8, and 12. Local educational agencies tend to view the NAEP as a benchmark to which the educational achievement of their students can be compared. In particular, state departments of education…

In order to identify medical students with potential academic weaknesses in specific areas, traditional admissions criteria and cognitive style were correlated with levels of performance in two preclinical courses. Data were gathered from the 1978 freshman class at the Medical College of Georgia. (Author/MLW)

Inferences that might be made from international educational assessments are discussed, considering issues of popular definition and sampling, assessment exercises, background variables, and statistical analyses. International assessments do tell something about academic achievement, but other approaches may provide more cost-effective information…

Normative data for the Wechsler Memory Scale-Revised were derived empirically using a sample of 50 volunteers between 25 and 34 years of age, who matched U.S. Census data on demographic characteristics. Differences between these empirical norms and published norms that were estimated statistically appear clinically significant. (SLD)

Too few researchers understand what statistical significance testing does and does not do, and consequently their results are misinterpreted. This Digest explains the concept of statistical significance testing and discusses the meaning of probabilities, the concept of statistical significance, arguments against significance testing,…

The discovery of disproportionate minority enrollments in special education classes has been a subject of considerable concern to federal, state, and local education officials alike for the past decade. Because the existence of disproportions is frequently thought to result from discriminatory placement practices on the part of local school…

Longitudinal measures of change are the most important kinds of estimates being produced from the National Longitudinal Study of the High School Class of 1972 (NLS). Several topics are presented in this report, most of which build on previous variance components analyses. The major areas covered are effects of stratification and clustering,…

Generalizability theory is described and applied to data collection methods for student ratings of instruction. Three generalizability coefficients (generalizing over both students and items, generalizing over students only, and generalizing over items only) are defined, and the appropriateness of each for various purposes is discussed.…