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)

A systematic investigation of the Grice modeling scheme for response time (RT) clarifies fundamental notions about RT modeling. The analysis presented can be used to determine what in a certain RT model constitutes a set of empirically testable assumptions and what is merely an arbitrary choice of mathematical language. (SLD)

Because it is sensitive to variability and permits partitioning of a distribution into the tails and center, the Hedges and Friedman Index can be used to investigate gender differences in each partition. It should yield greater insight into the nature of between-gender differences, as its application to Feingold's 1992 data illustrates. (SLD)

Examines the applicability of Lotka's Law, negative binomial distribution, and lognormal distribution for institutional productivity in the same way as it is to authors and their productivity. Results indicate that none of the distributions are applicable for institutional productivity in engineering sciences. (Author/LRW)

Examined five Rasch-model-based item-fit indices in terms of their distributional properties and the power of detecting item bias or differential item functioning. Results indicate that, although these five standardized item-fit indices did not depart significantly from a normal distribution, the Type I error rates were not reasonable. (Author/SLD)

Concentrations of chemical substances and microorganisms are often averaged using geometric means. Argues that the arithmetic mean is a better choice for summarizing data because arithmetic means are unbiased, easier to calculate and understand, scientifically more meaningful, and more protective of public health. Results of a simulation study…

Provides and illustrates a method to compute the expected number of misclassifications of examinees using three-parameter item response theory and two state classifications (mastery or nonmastery). The method uses the standard error and the expected examinee ability distribution. (SLD)