The Mantel-Haenszel (MH) statistic for identifying differential item functioning (DIF) commonly conditions on the observed test score as a surrogate for conditioning on latent ability. When the comparison group distributions are not completely overlapping (i.e., are incongruent), the observed score represents different levels of latent ability…

The accuracy of estimation procedures in item response theory was studied using Monte Carlo methods and varying sample size, number of subjects, and distribution of ability parameters for: (1) joint maximum likelihood as implemented in the computer program LOGIST; (2) marginal maximum likelihood; and (3) marginal Bayesian procedures as implemented…

Despite the increasing criticism of statistical significance testing by researchers, particularly in the publication of the 1994 American Psychological Association's style manual, statistical significance test results are still popular in journal articles. For this reason, it remains important to understand the logic of inferential statistics. A…

This paper investigates the performance of CATSIB (a modified version of the SIBTEST computer program) to assess differential item functioning (DIF) in the context of computerized adaptive testing (CAT). One of the distinguishing features of CATSIB is its theoretically built-in regression correction to control for the Type I error rates when the…

The L statistic of E. B. Page (1963) tests the agreement of a single group of judges with an a priori ordering of alternative treatments. This paper extends the two group test of D. W. Leitner and C. M. Dayton (1976), an extension of the L test, to analyze difference in consensus between two unequally sized groups of judges. Exact critical values…

Most of the multivariate statistical techniques rely on the assumption of multivariate normality. The effects of non-normality on multivariate tests are assumed to be negligible when variance-covariance matrices and sample sizes are equal. Therefore, in practice, investigators do not usually attempt to remove non-normality. In this simulation…

Several person-fit statistics have been proposed to detect item score patterns that do not fit an item response theory model. To classify response patterns as not fitting a model, a distribution of a person-fit statistic is needed. The null distributions of several fit statistics have been investigated using conventionally administered tests, but…

Attesting to the continuing economic strength and institutional vitality of the newspaper business in 1985, this booklet presents a statistical summary of the industry in the United States and Canada. The statistics cover a wide range of topics, including (1) number of daily newspapers, (2) daily newspaper circulation, (3) daily newspapers by…

This document consists entirely of 132 tables which present statistics on the projected population size of 12 racial and ethnic groups in California: non-Hispanic Whites; Blacks; Hispanics; Chinese; Filipinos; Asian Indians; Japanese; Koreans; Southeast Asians; Vietnamese; Other Asians; and other groups. An accompanying report deals with these…

This report is a follow-up to another, Population Change and California's Future, which presented projections of the population of different ethnic racial groups in California up to the year 2030. Two sets of statistics are presented in this report. The first set extends projections from the year 2030 to the year 2080. It is projected that…

Population projections are "what if" computational exercises. Given selected assumptions about future trends in fertility, mortality, and migration, population trends can be projected. Government and business planners need this information, and they also require enough time to put facilities in place to meet future needs. Everyone benefits from a…

Five distribution-free alternatives to parametric analysis of covariance (ANCOVA) are presented and demonstrated using a specific data example. The procedures considered are those suggested by Quade (1967); Puri and Sen (1969); McSweeney and Porter (1971); Burnett and Barr (1978); and Shirley (1981). The results of simulation studies investigating…

In 1980 the civilian labor force included over one million artists. This report, based on data collected by the U.S. Bureau of the Census, contains a detailed analysis of the distribution of those artists among various types of industries. Artists were assigned to one of 230 detailed industry categories, based upon the 1972 Standard Industrial…

The use of error pattern analysis can reduce the time and money spent on editing and correcting manuscripts. What is required is noting, classifying, and keeping a frequency count of errors. First an editor should take a typical page of writing and circle each error. After the editor has done a sufficiently large number of pages to identify an…

Pratt's measure C on the class concentration of bibliometric distributions is calculated and interpreted for the laws of Zipf, Mandelbrot, and Lotka and geometric distribution, and comparisons are made of the results. An explicit mathematical formula which unifies disparate theories is derived and tested. (Author/CLB)