Recent trends in the analysis of categorical or nominal variables were discussed for univariate, multivariate, and psychometric problems. It was shown that several statistical procedures commonly used with these problems have analogues which can be applied to assessing categorical variables. (Author/CTM)

This paper presents an empirical analysis of similarities and differences between two statistics, G and Phi, which treat genuinely dichotomous data. These results can aid researchers in selecting between these two statistics and in evaluating results from the use of one v the other. (Author)

The monotone regression function of Kruskal and the rank image of Guttman and Lingoes are fitted to bivariate normal samples and their statistical properties contrasted. Tables of results are presented. (Author/JKS)

Explores the asymptotic theory of a method of nonparametric item characteristic curve estimation based on kernel smoothing with the theory of obtaining the proper linear ordering of examinees with respect to their true latent abilities. Results support the usefulness of estimates of the type produced by the TESTGRAF program. (SLD)

Theoretical nonparametric conditions under which evidence from salary studies using observed merit measures can provide a basis for inferences of fairness are discussed. Latent variable models as parametric special cases of the general conditions presented are illustrated with real salary data. Implications for empirical studies of salary equity…

The isotonic ordinal probabilistic model (ISOP) is introduced as a common nonparametric theoretical structure for unidimensional models for quantitative, ordinal, and dichotomous variables. Fundamental theorems on dichotomous and polytomous weakly independent ordered systems are derived, and testing at the observed empirical level is discussed.…

Explores the use of the Friedman method of ranks (H. Friedman, 1937) as an inferential procedure for evaluating competing models in structural-equation modeling. Describes the attractive features of this approach, but raises important issues regarding the lack of independence of observations and the power of the test. (SLD)

Investigates the structure of item-pair conditional covariances given a unidimensional latent composite using a generalized semiparametric-modeling approach. Conditional covariances are shown to be highly informative about the latent dimensionality required to achieve local independence. Uses the new approach to justify the DIMTEST procedure. (SLD)

Explains genetic algorithms, a means of generating logical rules that predict one variable by relating it to others. Describes how they can be applied to analysis of survey data. (SK)

Assessed the relative merits of the Student "t" test and the Wilcoxon rank sum test under four population distributions and six sample-size pairings through Monte Carlo methods. The Wilcoxon rank sum test demonstrated an advantage in statistical power for nonnormal distributions (but not normal distributions), with fewer Type III errors…

Studied the use of the person response function (PRF) for identifying nonfitting item score patterns. Proposed a person-fit method reformulated in a nonparametric item response theory (IRT) context. Conducted a simulation study to compare the use of the PRF with a person-fit statistic, resulting in the conclusion that the PRF can be used as a…

Introduces this special issue on nonparametric item response theory and discusses its use in psychological and sociological research. Outlines each of the eight articles in the issue. (SLD)

Discusses usability and interpretation issues for single-strategy cognitive assessment models that posit a stochastic, conjunctive relationship between a set of cognitive attributes to be assessed and performance on particular items/tasks of the assessment. Also discusses stochastic ordering and monotonicity properties that enhance the…

Discusses the papers in this special issue, emphasizing the practical applicability of nonparametric item response theory (NIRT) and how NIRT addresses lack-of-fit issues. Also discusses the ability of NIRT to assess latent multidimensionality and the relation of latent multidimensionality analyses to construct validity. (SLD)

A family of integrals over infinite intervals appears frequently in the statistical literature on non-parametric regression. This note presents two simple transform methods, based on beta function and Parseval identity, to explicitly evaluate these integrals. These methods will benefit researchers and practitioners working in non-parametric…