Person-fit methods are used to uncover atypical test performance as reflected in the pattern of scores on individual items in a test. Unlike parametric person-fit statistics, nonparametric person-fit statistics do not require fitting a parametric test theory model. This study investigates the effectiveness of generalizations of nonparametric…

U.S. state educational testing programs administer tests to track student progress and hold schools accountable for educational outcomes. Methods from item response theory, especially Rasch models, are usually used to equate different forms of a test. The most popular method for estimating Rasch models yields inconsistent estimates and relies on…

The possibility of using component analysis for nominal data is discussed. Two nominal scale correlation coefficients are applicable. Tschuprow's coefficient and the J index. The reason is that they satisfy the requirements of a scalar product between normalized vectors in a Euclidean space. Some characteristics of these coefficients are…

Kruskal has proposed two modifications of monotone regression that can be applied if there are ties in nonmetric scaling data. In this note Kruskal's conjecture that his algorithms give the optimal least squares solution of these modified monotone regression problems is proven. Also, an additional approach is proposed. (Author/JKS)

An algorithm, using a short cut due to Feldman and Klingler, for the Fisher-Yates exact test is presented. The algorithm is quick, simple and accurate. (Author)

A nonparametric class of intervariable association indeces is presented that follows the logic of point symmetry adjustment of the Pearsonian phi coefficient. This approach is extended to multipoint scales. These indeces may be attractive alternatives to the Pearson correlation coefficient for multivariate analyses. (SLD)

Extreme-value statistics is often used to estimate so-called return values (actually related to quantiles) for environmental quantities like wind speed or wave height. A basic method for estimation is the method of block maxima which consists in partitioning observations in blocks, where maxima from each block could be considered independent.…

Contractor performance evaluation enables agents to make informed purchasing decisions, provide feedback to contractors/vendors, and help improve service quality and customer satisfaction. However, both public and private organizations sometimes fail to do so, as is the case at a division of a government organization located in a northeastern U.S.…

Tests of model misfit are often performed to validate the use of a particular model in item response theory. Douglas and Cohen (2001) introduced a general nonparametric approach for detecting misfit under the two-parameter logistic model. However, the statistical properties of their approach, and empirical comparisons to other methods, have not…

The program can perform any one of those nonparametric statistical methods that is mentioned in Sidney Siegel's classical work on the subject. The user is free to select among the methods and also among the samples that are read by the program. When a particular set of samples has been treated in the prescribed way, a new set may follow together…

Two nonparametric statistical methods, the inverse normal scores method and the rank order transformation, are compared for use in discriminant function analysis. The methods are compared for both normal and non-normal distributions. When the distributions are normal, the rank and inverse normal scores methods are effective substitutes for the…

A measure of multiple rank correlation is proposed for the situation of no tied observations in the variables. The measure is a weighted average of two squared Kendall taus. The measure is equivalent to one proposed by Moran. (Author/JKS)

Problems associated with ranking a large number of objects are discussed. It is recommended that only a subset of the most preferred objects be ranked by each judge. A test statistic for testing the hypothesis of no difference in preference among the objects is developed for the recommended procedure. (Author/JKS)

A computer program is described which performs the Bowker test of symmetry in a square contingency table, the Light-Margolin and Pearson tests for homogeneity in nonorder contingency tables, the Kruskal-Wallis test for ordered dependent variables, and the Kandall and Maxwell tests for monotonic trends in ranks. (Author)