Use of confirmatory factor analysis (CFA) with nonzero latent means in testing six different measurement models from classical test theory is discussed. Implications of the six models for observed mean and covariance structures are described, and three examples of the use of CFA in testing the models are presented. (SLD)

Studied the extent to which three appropriateness indexes, Z(sub 3), ECIZ4, and W, are well standardized in a Monte Carlo study. The ECIZ4 most closely approximated a normal distribution, and its skewness and kurtosis were more stable and less affected by test length and item response theory model than the others. (SLD)

Examines the 80/20 rule that relates to productive sources in a bibliography. Highlights include applications in library acquisition policies, library circulation and weeding policies, science policy studies, information science, and econometrics; formulae of Burrell and of Egghe; probabilistic proofs; geometric distributions; Lotka distribution;…

The precision of the group-based item-response theory (IRT) model applied to school ability estimation is described, assuming use of Bayesian estimation with precision represented by the standard deviation of the posterior distribution. Similarities with and differences between the school-based model and the individual-level IRT are explored. (SLD)

A useful method is proposed for identifying a variable as inconsistent in factor analysis. The procedure, based on the likelihood principle, is illustrated. Statistical properties such as the effect of misspecified hypotheses, the problem of multiple comparisons, and robustness to violation of distributional assumptions are investigated. (SLD)

To assess problems in hypothesis testing and model comparisons based on normed indices caused by latent class models with sparse contingency tables, a simulation was carried out investigating the distributions of the likelihood ratio statistic, the Pearson statistic chi-square, and a new goodness of fit statistic. (SLD)

Describes a study that analyzed transaction logs of users of Excite, an Internet search service. Highlights include data on sessions (changes in queries, number of pages viewed, and relevance feedback), queries (number of search terms and the use of logic and modifiers), and terms (rank/frequency distribution); user characteristics; and failure…

Reports on the development of the Hebrew language translation of the Bath County Computer Attitude Scale among a sample of 339 undergraduate students in Israel. The data support the reliability and validity based on frequency, correlation, reliability, and factor routines analyzed with the SPSS (Statistical Package for the Social Sciences).…

An alternative two-stage least squares (2SLS) estimator of the parameters in LISREL type models is proposed and contrasted with existing estimators. The new 2SLS estimator allows observed and latent variables to originate from nonnormal distributions, is consistent, has a known asymptotic covariance matrix, and can be estimated with standard…

A trilinear chart for understanding the distribution of achievement levels of students' performance in the National Assessment of Educational Progress (NAEP) is described and its use illustrated with data from the 1992 state NAEP mathematics assessment. Trends for all 44 participating jurisdictions are simultaneously displayed. (SLD)

Analyzed data from a session of the General Certificate of Secondary Education (GCSE) mathematics examination to identify items displaying a bi-modal expected score distribution, try to explain the bi-modality, rescore the items to remove under-used middle categories, and determine the effect on test reliability of rescoring the data. Discusses…

How do people judge which of 2 risks claims more lives per year? The authors specified 4 candidate mechanisms and tested them against people's judgments in 3 risk environments. Two mechanisms, availability by recall and regressed frequency, conformed best to people's choices. The same mechanisms also accounted well for the mapping accuracy of…

The need for hands-on computer laboratory experience in undergraduate and graduate statistics education has been firmly established in the past decade. As a result a number of attempts have been undertaken to develop novel approaches for problem-driven statistical thinking, data analysis and result interpretation. In this paper we describe an…

A longstanding debate focuses on whether suicide and homicide rates walk hand in hand or whether they are reciprocally related. Much of the research on this issue investigates whether suicide or homicide predominates in certain geographic areas or whether they trend together over time. We theorize that the degree of social integration and social…

Event-related potentials were measured as subjects read sentences presented word by word. A small N400 and a robust P600 effect were elicited by verbs that assigned the thematic role of Agent to their preceding noun-phrase argument when this argument was inanimate in nature. The amplitude of the P600, but not the N400, was modulated by the…