One of the important underlying assumptions of all item response theory (IRT) models is that of local independence. This assumption requires that the response to an item on a test not be influenced by the response to any other items. This assumption is often taken for granted, with little or no scrutiny of the response process required to answer…

The purpose of this study was to develop a single procedure for comparing population variances which could be used for distribution forms. Bootstrap methodology was used to estimate the variability of the sample variance statistic when the population distribution was normal, platykurtic and leptokurtic. The data for the study were generated and…

In research, data sets often occur in which the variance of the distribution of the dependent variable at given levels of the predictors is a function of the values of the predictors. In this situation, the use of weighted least-squares (WLS) or techniques is required. Weights suitable for use in a WLS regression analysis must be estimated. A…

This paper reviews recent work in factor analysis of categorical variables. Emphasis is on the generalized least squares solution. A section on maximum likelihood solution focuses on extensions of the classical model, especially the normal case. Many of the recent developments have taken place within this context, and it provides a unified…

In latent trait theory the latent space, or space of the hypothetical construct, is usually represented by some unidimensional or multi-dimensional continuum of real numbers. Like the latent space, the item response can either be treated as a discrete variable or as a continuous variable. Latent trait theory relates the item response to the latent…

The nonparametric approach to test theory discussed here has its roots in the early work of Guttman, Lazarsfeld, and Meredith; and more recently in the work of Cliff and in Tatsuoka and Tatsuoka. Mokken's extensive treatment of this subject concentrated on defining, constructing, and testing unidimensional scales, based on responses to dichotomous…

A subset of Statistical Process Control (SPC) methodology known as Control Charting is introduced. SPC methodology is a collection of graphical and inferential statistics techniques used to study the progress of phenomena over time. The types of control charts covered are the null X (mean), R (Range), X (individual observations), MR (moving…

The paper states that quantification is neither ethical nor unethical, but is ethically neutral. It is the behavior or intent of the human being that is clearly a matter of ethical concern. Like numerology and the sects of inumerates and qualitatives, there is not so much an unethical practice that is supported as there is a lack of vision and…

Meta-analysis is a technique for combining the summary statistics from previously conducted research studies to indicate the direction of results and provide an index of the magnitude of effect size. This paper focuses on the effect of the violation of the assumption of independence (that the value of any included statistic is in no way…

This document investigates the widely used school climate assessment instrument, the CFK Ltd. School Climate Profile. Part A (General School Climate Factors) was administered by school to a junior high campus (n=257) and a high school campus (n=906) in a major metropolitan area in the Southwestern United States to gather data for administrative…

A normally distributed data set of 1,000 values--ranging from 50 to 150, with a mean of 50 and a standard deviation of 20--was created in order to evaluate the bootstrap method of repeated random sampling. Nine bootstrap samples of N=10 and nine more bootstrap samples of N=25 were randomly selected. One thousand random samples were selected from…

The study has hinted that programed learning among adults in Tanzania fares as well as face-to-face teaching among equivalent students, and that a combination of methods tends to produce better results than face-to-face instruction alone; further research, however, remains to be done with enlarged samples. (Author/AJ)

Self-instructional modules used as one of several learning delivery systems at the university were planned for extensive use as an integral part of the academic program. Students who have completed the modules were asked to complete a specially prepared evaluation form. The results of the responses obtained are summarized, and the statistical…

A study was designed to investigate the ways in which graduate students respond to the fact that their competence must be repeatedly valued by means of grades, written and oral examinations, letters of recommendations, dissertation approvals, and various less official procedures. Some students, the gamesmen, have developed strategies for evading…

The major contributions of research to the organization and delivery of health services in the past decade (circa 1972-1982) are described and some important areas for further research are indicated in the three main sections of this paper. The first section points out problems associated with the current state of the applied field of health…