Investigated effect of the high skewness typically present in distributions of depressive symptom scores on findings of a gender difference in depression. Skewness allowed a few extreme scores among women to produce significant between-groups differences in untransformed scores even when male and female groups' distributions were otherwise…

Proposes split model for index term distribution in document set that uses rank function for high frequency terms and size function for low frequency terms; the point of transition is determined either empirically or by rule. Distributions to describe index term exhaustivity and term co-occurrence are considered briefly. (36 references) (EJS)

The Generalized Inverse Gaussian-Poisson Distribution is suggested as an all-embracing mathematical model for bibliometric frequency distributions. Twelve examples are given which show that the new model cannot be rejected by virtue of an objective chi-squared test. A mathematical appendix and 20 references are included. (Author/EJS)

Rosenthan's (1979) concept of fail-safe N has thus far been applied to probability levels exclusively. This note introduces a fail-safe N for effect size. (Author)

This paper presents a summary of action research investigating statistics students' understandings of the sampling distribution of the mean. With four sections of an introductory Statistics in Education course (n=98 students), a computer simulation activity (R. delMas, J. Garfield, and B. Chance, 1999) was implemented and evaluated to show…

Two new indices to detect answer copying on a multiple-choice test, S(1) and S(2) (subscripts), are proposed. The S(1) index is similar to the K-index (P. Holland, 1996) and the K-overscore(2), (K2) index (L. Sotaridona and R. Meijer, in press), but the distribution of the number of matching incorrect answers of the source (examinee s) and the…

The effects of skewed theta distributions on indices of differential item functioning (DIF) were studied, comparing Mantel Haenszel (N. Mantel and W. Haenszel, 1959) and DFIT (N. S. Raju, W. J. van der Linden, and P. F. Fleer) (noncompensatory DIF). The significance of the study is that in educational and psychological data, the distributions one…

Mislevy (1984, 1985) introduced an EM algorithm for estimating the parameters of a latent distribution model that is used extensively by the National Assessment of Educational Progress. Second order asymptotic corrections are derived and applied along with more common first order asymptotic corrections to approximate the expectations required by…

An exploratory reliability and validity study was conducted of a relatively new response scale developed in the marketing field. Unlike many Likert-type scales, the "unbounded write-in" scale is claimed to produce distributions that more closely approximate normal distributions. This type of scale has been used in large-scale marketing studies.…

The purpose of this paper is to describe the techniques used in establishing the concordance tables between the Test of English as a Foreign Language (TOEFL), paper and pencil (P&P), and computer-based testing (CBT) sections and total reported score scales. Listening, reading, and composite structure and essay scores plus a total score are…

The passage of the No Child Left Behind Act and subsequent regulations have challenged state education agencies (SEAs) in many ways and ensuring the appropriate inclusion of students with disabilities has been a unique challenge. The recent publication of regulations on alternate assessments with alternate achievement standards (34 CFR Part 200)…

The bivariate normal distribution can be used to determine the prevalence of reading disabilities when the primary variables are reading achievement and IQ and when the correlation between reading and IQ is known or can be estimated. The advantages and diadvantages of the bivariate normal distribution are discussed. (Author/CL)

Nonparametric and robust statistics (those using trimmed means and Winsorized variances) were compared for their ability to detect treatment effects in the two-sample case. The use of two specialized tests, designed to be sensitive to treatment effects when data distributions are skewed to the right, is not supported by the analyses. (SLD)

Applies a prefix trie index, or trie hashing, to the problem of providing fast search times, fast load times, and fast update properties in a bibliographic or full-text retrieval system with inverted files. Statistics are given for a test database consisting of an online catalog at the University of Western Ontario. (Author/LRW)

The utility of the three-form design coupled with maximum likelihood methods for estimation of missing values was evaluated. Simulation studies demonstrate that maximum likelihood estimation and multiple imputation methods produce the most efficient and least biased estimates of variances and covariances for normally distributed and slightly…