Alternating least squares and optimal scaling are presented as two approaches to the quantitative analysis of qualitative data. A variety of statistical approaches to this problem are discussed. Three examples are presented. (JKS)

Many researchers, including Buriel (EJ 187 987), incorrectly compared the results in each study with null hypotheses of zero differences between means or zero population correlations. Instead, a test of difference between the mean differences in the two samples or the direct comparison of the two sample correlations is required. (Author/CP)

Hollingsworth recently showed a posttest contrast for analysis of variance situations that, for equal sample sizes, had several favorable qualities. However, for unequal sample sizes, the contrast fails to achieve status as a maximized contrast; thus, separate testing of the contrast is required. (Author/GSK)

An extension of the discussion of loglinear models presents post hoc procedures for statistically evaluating treatment effects, contrasts, and confidence intervals, illustrating methods for main effect and interaction contrasts and paying special attention to odds ratios and their interval estimates. Procedures for treating variables as…

This simulation study considered the effects on statistical measures of test dimensionality that result from systematic sampling variation in both a single- and a double-trait assessment model. Results suggest that there are distinct psychological and psychometric states of test dimensionality, and that psychometric unidimensionality may be…

The history of generalizability theory (G theory) is told from the perspective of one researcher's experiences, describing psychometric and scientific perspectives that influenced the development of G theory and its adoption. Work that remains to be done in the field is outlined. (SLD)

Differentiating between additive (quantitative) and interactive (qualitative) effects of comorbidity has important treatment implications. This study illustrates the heuristic superiority of a multifactorial approach over simple group comparisons in testing quantitative versus qualitative models of comorbidity. Analysis of variance was used to…

In this article, we emphasize that the Rasch model is not only very useful for psychological test calibration but is also necessary if the number of solved items is to be used as an examinee's score. Simplified proof that the Rasch model implies specific objective parameter comparisons is given. Consequently, a model check per se is possible. For…

This article is concerned with the seemingly simple problem of testing whether latent factors are perfectly correlated (i.e., statistically indistinct). In recent literature, researchers have used different approaches, which are not always correct or complete. We discuss the parameter constraints required to obtain such perfectly correlated latent…

We introduce a family of goodness-of-fit statistics for testing composite null hypotheses in multidimensional contingency tables. These statistics are quadratic forms in marginal residuals up to order "r." They are asymptotically chi-square under the null hypothesis when parameters are estimated using any asymptotically normal consistent…

This article describes an example which is useful when teaching hypothesis testing in order to highlight the interrelationships that exist among the level of significance, the sample size and the statistical power of a test. The example also allows students to see how what they learn in the classroom directly affects the content of some of the…

A type of data layout that may be considered as an extension of the two-way random effects analysis of variance is characterized and modeled based on group invariance. The data layout seems to be suitable for several scenarios in psychometrics, including the one in which multiple measurements are taken on each of a set of variables, and the…

The article examines changes in language testing textbooks in English since Lado (1961) and proposes that two trends may be discerned. The first shows how the growing professionalism of the field has required an expansion in teaching materials to meet the need for new training programmes. What the expansion also shows is the desire, again a mark…

Multilog (Thissen, 1991) was used to estimate parameters of 225 items from the Quebec Adaptive Behavior Scale (QABS). A database containing actual data from 2,439 subjects was used for the parameterization procedures. The two-parameter-logistic model was used in estimating item parameters and in the testing strategy. MicroCAT (Assessment Systems…

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…