A Monte Carlo evaluation of four test statistics for comparing dependent zero-order correlations was conducted with four sample sizes and three population distributions. Results indicate that choice of optimal test statistic depends on sample size and distribution, and predictor intercorrelation and effect size or magnitude of the…

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…

Compared the nominal and empirical null distributions of the standardized log-likelihood statistic for polytomous items for paper-and-pencil (P&P) and computerized adaptive tests (CATs). Results show that the empirical distribution of the statistic differed from the assumed standard normal distribution for both P&P tests and CATs. Also…

Presents a probability model of the occurrence of index terms used to derive discrete distributions which are mixtures of Poisson and negative binomial distributions. These distributions give better fits than the simpler Zipf distribution, have the advantage of being more explanatory, and can incorporate a time parameter if necessary. (25…

Demonstrates the use of the Waring distribution as a model for the frequency distribution of scientific productivity. Methods for testing the fit at both ends of the distribution, as well as for estimating the parameters of the distribution and the total number of scientists, are outlined. (16 references) (Author/CLB)

Presents a system of software and analysis for the development of mathematical models designed to explain the structure in large bibliographic data sets. The discussion covers the goodness of fit obtained in testing and replications, and the implications for the control of large information systems. (six references) (CLB)

Describes the basic concepts of Lotka's law of scientific productivity, Bradford's law of scatter, and Zipf's law of word occurrence. The discussion covers the validity of these laws and useful applications of each law to specific library applications. (13 references) (CLB)

Large-sample standard errors of linear equating for the counterbalanced design are derived using the general delta method. Computer simulations found that standard errors derived without the normality assumption were more accurate than those derived with the normality assumption in a large sample with moderately skewed score distributions. (SLD)

The reliability coefficient is predicted from the test information function (TIF) or two modified TIF formulas and a specific trait distribution. Examples illustrate the variability of the reliability coefficient across different trait distributions, and results are compared with empirical reliability coefficients. (SLD)

A Monte Carlo experiment was conducted to investigate the performance of bootstrap methods in normal theory maximum likelihood factor analysis when the distributional assumption was satisfied or unsatisfied. Problems arising with the use of bootstrap methods are highlighted. (SLD)

In response to Leonard (EC 600 867), the article suggests that Leonard's idea that many language-impaired children merely represent the low end of the normal distribution of language ability does not eliminate neuropathology as one possible primary cause of language impairment. (Author/DB)

Reports on a study that examined the behavior of the journal productivity distribution curve over time using bibliographic references for research reports in chemistry and physics by Croatian authors over a 10-year period. Data characteristics of interest are described; and results regarding one-year distributions, changes in data characteristics,…

Corrects an error in the calculation of the Kolmogorov-Smirnov (KS) statistic when it is used to empirically confirm or deny the generalized Lotka's law. Examples from the literature are given of both correct and incorrect uses of the KS test and Lotka equations with cumulative distribution functions (CDFs). (six references) (LRW)

An approximate statistical test is derived for the hypothesis that the intraclass reliability coefficients associated with two measurement procedures are equal. Control of Type 1 error is investigated by comparing empirical sampling distributions of the test statistic with its derived theoretical distribution. A numerical illustration is…

Proposes a plotting position formula for the Pearson type III distribution in the analysis of historical flood information. Presents results of a numerical example using actual flood data to confirm the appropriateness of the plotting formula. (24 references) (MDH)