This study aimed to assess the accuracy of the empirical item characteristic curve (EICC) preequating method given the presence of test speededness. The simulation design of this study considered the proportion of speededness, speededness point, speededness rate, proportion of missing on speeded items, sample size, and test length. After crossing…

Mokken scale analysis is a probabilistic nonparametric approach that offers statistical and graphical tools for evaluating the quality of social science measurement without placing potentially inappropriate restrictions on the structure of a data set. In particular, Mokken scaling provides a useful method for evaluating important measurement…

Standard approaches for estimating item response theory (IRT) model parameters generally work under the assumption that the latent trait being measured by a set of items follows the normal distribution. Estimation of IRT parameters in the presence of nonnormal latent traits has been shown to generate biased person and item parameter estimates. A…

This study combined the kernel smoothing procedure and a nonparametric differential item functioning statistic--Cochran's Z--to statistically test the difference between the kernel-smoothed item response functions for reference and focal groups. Simulation studies were conducted to investigate the Type I error and power of the proposed…

The distance between nonparametric and parametric item characteristic curves has been proposed as an index of goodness of fit in item response theory in the form of a root integrated squared error index. This article proposes to use the posterior distribution of the latent trait as the nonparametric model and compares the performance of an index…

A nonparametric tree classification procedure is used to detect differential item functioning for items that are dichotomously scored. Classification trees are shown to be an alternative procedure to detect differential item functioning other than the use of traditional Mantel-Haenszel and logistic regression analysis. A nonparametric…

Lambda and kappa coefficients of nominal scale association are developed for research hypotheses that involve predictions of modality, agreement, or some theoretically specified configuration. The proposed new coefficient is offered as an alternative to Goodman and Kruskal's lambda. (Author/CTM)

Two r coefficients of association are discussed. One of the coefficients can be applied to any nonparametric test statistic (NTS) in which a normal approximation equation is appropriate. The other coefficient is applicable to any NTS in which exact probabilities are known. (Author/RL)

In this paper, a test based on rank sums is considered specifically for problems where there is a priori indication that the experimental condition may cause extreme reactions in both directions. (Authors)

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)

Describes the MINISIZE 2 computer program, which permits the user to determine the effect size and the minimum sample size needed so that results of a given analysis will be statistically significant. Explains the program's operation and provides examples. (SLD)