This article describes psychometric testing of an Icelandic adaptation of the "Adult Reading History Questionnaire" (ARHQ), designed to detect a history of reading difficulties indicative of dyslexia. Tested in a large and diverse sample of 2,187 adults, the Icelandic adaptation demonstrated internal consistency reliability (Cronbach's…

The Census Bureau has historically grouped high school diploma holders along with those who hold "high school equivalent" credentials. Among these is the credential earned through successfully passing the General Education Development (GED) test. Interest in identifying those with GEDs has recently increased, in part from debate within…

Assessing a high school's effectiveness is not straightforward. Comparing a school's standardized test scores to those of other schools is one approach to measuring effectiveness, but a major objection to this method is that students' test scores tend to be related to students' "socioeconomic" status--family household income, for…

This study compared classical test theory (CTT) and item response theory (IRT). The behavior of the item and person statistics derived from these two measurement frameworks was examined analytically and empirically using a data set obtained from BILOG (R. Mislay and D. Block, 1997). The example was a 15-item test with a sample size of 600…

Explains Type/Token-Taken informetrics as a new part of informetrics that studies the use of items rather than the items themselves. Highlights include the frequency distribution of Type/Token-Taken informetrics; the Lotka frequency law; linguistics; a comparison of Type/Token with Type/Token-Taken informetrics; and proofs of theorems. (Author/LRW)

Proposes a method for the comparative analysis of concentration in author productivity distributions; selects suitable measures, Gini's index and number of authors, for two viewpoints regarding productivity; discusses statistical peculiarities of author productivity data; and explains developmental profiles which take into account sample size…

Discusses the problem of determining an adequate sample size for an information retrieval experiment comparing two systems on separate samples of requests. The application of statistical methods to information retrieval experiments is discussed, the Mann-Whitney U Test is used for determining minimum sample sizes, and variables and distributions…

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)

Use of confirmatory factor analysis (CFA) with nonzero latent means in testing six different measurement models from classical test theory is discussed. Implications of the six models for observed mean and covariance structures are described, and three examples of the use of CFA in testing the models are presented. (SLD)

The purpose of this study was to develop a single procedure for comparing population variances which could be used for distribution forms. Bootstrap methodology was used to estimate the variability of the sample variance statistic when the population distribution was normal, platykurtic and leptokurtic. The data for the study were generated and…