The theoretical differences between the traditional definition of dimensionality and the more recently defined notion of essential dimensionality are presented. Monte Carlo simulations are used to demonstrate the utility of W. F. Stout's procedure to assess the essential unidimensionality of the latent space underlying a set of terms. The…

Two approaches of statistical testing are critically reviewed. A new approach, which is a hybrid of the two, is proposed. The new approach requires the researcher to think about the two types of potential inferential errors and an explicit alternative hypothesis of interest. (VM)

Assessment exercises (items) in three different formats--multiple-choice with an "I don't know" (IDK) option, multiple-choice without the IDK, and open-ended--were placed at the beginning, middle and end of 45-minute assessment packages (instruments). A balanced incomplete blocks analysis of variance was computed to determine the biasing…

A statistical analysis was conducted to examine changes across time in some school districts of Pennsylvania. Comparisons were made for grades 5, 8, and 11 during two assessment periods. The Educational Quality Assessment data provided the basis for analysis. Correlation coefficients for school mean goal scores are displayed. Changes at the three…

One of the overriding problems of any psychometric study is that aspects of behavior that are nonquantifiable or difficult to quantify are not considered. The other side of this coin is that those aspects of behavior that are easiest to quantify tend to be what are examined. In evaluating bilingual education programs, problems are found in the…

This bibliography provides abstracts of 28 recent (most were published since 1993) books, journal articles, and other documents concerned with testing accommodations for students with disabilities. The emphasis was on studies examining the effects of testing accommodations on the technical integrity of assessment measures. However, the…

This paper focuses on the questions which arise as test practitioners monitor score scales derived from latent trait theory. Large scale assessment programs are dynamic and constantly challenge the assumptions and limits of latent trait models. Even though testing programs evolve, test scores must remain reliable indicators of progress.…

This report reviews the current literature (mostly since 1993) on testing accommodations for students with disabilities, with an emphasis on studies examining the effects of testing accommodations on the technical integrity of assessment measures. The report notes a continuing lack of empirical research on testing accommodations, but evidence of…