K. May and W. A. Nicewander recently concluded (1994) that percentile ranks are inferior or raw scores as indicators of latent ability. It is argued that their conclusions are incorrect, and an error in their derivation is identified. The incorrect equation results in an incorrect conclusion, as work by F. M. Lord (1980) also indicates.…

Examines the topic of Fuzzy Set Theory to determine the overlap of coverage in bibliographic databases. Highlights include examples of comparisons of database coverage; frequency distribution of the degree of overlap; records with maximum overlap; records unique to one database; intra-database duplicates; and overlap in the top ten databases.…

Some results on how the Alexander-Govern heteroscedastic analysis of variance (ANOVA) procedure (R. Alexander and D. Govern, 1994) performs under nonnormality are presented. This method can provide poor control of Type I errors in some cases, and in some situations power decreases as differences among the means get large. (SLD)

Studied whether the theoretical sampling distribution of the U3 person-fit statistic is in agreement with the simulated sampling distribution under different item response theory models and varying item and test characteristics. Simulation results suggest that the use of standard normal deviates for the standardized version of the U3 statistic may…

Describes a study that examined Top 40 singles chart data to determine whether the frequency distribution of artist productivity fit either of two laws of scatter (Lotka Law of Scientific Productivity or Bradford Law of Scatter). Possible reasons for the lack of statistical significance found between the theoretical and observed distributions are…

The frequencies of "m" independent "p-way" contingency tables are analyzed by a model that assumes that the ordinal category data in each of "m" groups are generated from a latent continuous multivariate normal distribution. The model permits analysis of several groups of individuals simultaneously. (TJH)

Identifies four components of a good predictive lossless image compression method: (1) pixel sequence, (2) image modeling and prediction, (3) error modeling, and (4) error coding. Highlights include Laplace distribution and a comparison of the multilevel progressive method for image coding with the prediction by partial precision matching method.…

Analyzes the use and distribution of the adverbs "almost" and "nearly" based on the LOB corpus, data compiled at the universities of Lancaster (England), Oslo (Norway), and Bergen (Norway) between 1970 and 1978. (six references) (CFM)

This article offers comments and clarifications of Egghe's paper, which dealt with information production processes (IPP) and the Gini index. Topics addressed include the length of the Lorenz curve as a concentration measure, the discrete duality operator, and a Bradford-Leimkuhler distribution. (10 references) (LRW)

Reviews informetric, or bibliometric, distributions, including Lotka's, rank frequency distributions, Zipf functions, Mandelbrot functions, Leimkuhler functions, and Bradford's formulations. An example of the use of these techniques to analyze song texts of Thomas Dolby is given, and results are reported that show a fit with a Leimkuhler function.…

Examined the degree to which coefficient alpha is affected by including items with different distribution shapes within a unidimensional scale. Computer simulation results indicate that reliability does not increase dramatically as a result of using differentially shaped items within a scale. Discusses implications for test construction. (SLD)

Presents a hierarchical Bayes approach to modeling parameter heterogeneity in generalized linear models. The approach combines the flexibility of semiparametric latent class models that assume common parameters for each subpopulation and the parsimony of random effects models that assume normal distributions for the regression parameters.…

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…

Discusses four reasons for promoting the use of confidence intervals: (1) ease of interpretation; (2) links with familiar statistical tests; (3) promotion of meta-analytic thinking; and (4) increase of information about precision. Discusses calculations of confidence intervals for a basic standardized effect size measure and discusses software for…

Illustrates the computation of confidence intervals for effect sizes for some analysis of variance applications and shows how the use of intervals involving noncentral distributions is made practical by new software. (SLD)