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…

Distinguishes two conceptions of sample and sampling that emerged in the context of a teaching experiment conducted in a high school statistics class. Suggests that the conception of a sample as a quasi- proportional, small-scale version of the population is a powerful one to target for instruction. (Author/KHR)

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…

Describes the use of computer graphics simulations to enhance student understanding of sampling distributions that arise in introductory statistics. Highlights include the distribution of sample proportions, the distribution of the difference of sample means, the distribution of the difference of sample proportions, and the distribution of sample…

Describes an expert system that can identify documents erroneously categorized by indexers working within a prior category scheme. The discussion covers the results of a test of the system and its implications for automatic indexing systems. (14 references) (CLB)

Details the characteristics of authority records in the machine readable Library of Congress Subject Headings. Statistics are given on occurrences of variable length fields and the length and maximum length of such fields in subject heading records. The usefulness of these statistics for system design is discussed. (five references) (CLB)

It is suggested that using an unbiased estimate of the weight matrix may eliminate the small or intermediate sample size bias of the asymptotically distribution-free (ADF) test statistic. Results of simulations show that test statistics based on the biased estimator or the unbiased estimate are highly similar. (SLD)