The implications of a mathematical model of test scores are explored where the data are limited to a random sample of items without replacement from an indefinitely large population or item domain in which items are scored either zero or one. The purpose is to obtain an unbiased estimate of a student's proportion of items correct in the item…

A general method for estimating the unknown coefficients in a set of linear structural equations is described. In its most general form the method allows for both errors in equations (residuals, disturbances) and errors in variables (errors of measurement, observational errors) and yields estimates of the residual variance-covariance matrix and…

The 1987-88 Schools and Staffing Survey (SASS) looked at a national sample of elementary and secondary public and private schools. Components of the SASS, a data collection effort of the National Center for Education Statistics, were surveys of teacher demand and shortage, schools, administrators, and teachers. Approximately 13,000 schools and…

The percentage of students at/above a cut point (PAAC) is one of the most common measures used for reporting school-level performance relative to a proficiency standard (L. Cronbach, N. Bradburn, and D. Horvitz, 1994). The two purposes of this study were to introduce procedures for estimating standard errors for school PAACs under a…

The purpose of this research was to study the effect of the three different ways of increasing the number of points contributed by constructed response (CR) items on the reliability of test scores from mixed-item-format tests. The assumption of unidimensionality that underlies the accuracy of item response theory model-based standard error…

In this study we test the performance of some nonexperimental estimators of impacts applied to an educational intervention--reduction in class size--where achievement test scores were the outcome. We compare the nonexperimental estimates of the impacts to "true impact" estimates provided by a random-assignment design used to assess the…

Contends that the nature of physics has been misrepresented by blurring or ignoring important distinctions between "errors" and "discrepancies" and that dealing with these and related problems can improve students' enjoyment of labs and understanding of physics. Nature of physics, role of experiments, experimental errors, and error analysis are…

Willmott's comparison of General Certificate of Education (GCE) scores in 1968 and 1973 is reexamined. The trend toward an increasing percentage of students who pass is confirmed, but estimates of standard errors indicate that subtest differences may be attributed to the sampling plan. (CP)

The stability of scores on 2 types of performance assessments, an observed hands-on investigation and a notebook surrogate, was investigated for 29 sixth graders on 2 occasions. Results indicate that student performance and procedures changed and that generalizability across occasions was moderate. Implications for assessment are discussed. (SLD)

Addresses three issues concerning the assessment of the overrating and underrating of academic competence: (1) the impossibility of separating effects of overrating and underrating from effects of perceived and actual competence; (2) the questionable validity of Connell and Ilardi's method; and (3) the proposal of a new method and its implications…

Type I error rates of four multivariate tests (Pilai-Bartlett trace, Johansen's test, James' first-order test, and James' second-order test) were compared for heterogeneous covariance matrices in 360 simulated experiments. The superior performance of Johansen's test and James' second-order test is discussed. (SLD)

The ability of 3-way INDSCAL and ALSCAL models to recover true structure in proximity data based on 2-dimensional configurations varying in number of subjects (15 and 20) and stimuli, amount of error, and monotonic transformation is examined. INDSCAL outperformed metric and nonmetric ALSCAL in all conditions. (SLD)

Three variations of a least squares regression model are presented that are suitable for determining and correcting for rating error in designs in which examinees are evaluated by a subset of possible raters. Models are applied to ratings from 4 administrations of a medical certification examination in which 40 raters and approximately 115…

The seven cohort studies of the relation between prenatal and postnatal exposure to polychlorinated biphenyls (PCBs) to cognitive, neuropsychological and behavioral development have suggested that exposure to PCBs can cause persistent changes in cognitive functioning. D.V. Cicchetti, A.S. Kaufman, and S.S. Sparrow (this issue) apply six scientific…

The analytically derived asymptotic standard errors (SEs) of maximum likelihood (ML) item estimates can be approximated by a mathematical function without examinees' responses to test items, and the empirically determined SEs of marginal maximum likelihood estimation (MMLE)/Bayesian item estimates can be obtained when the same set of items is…