Two techniques for determining a straight line fit to data are compared. This article reviews two simple techniques for fitting a straight line to a set of data, namely the method of averages and the method of least squares. These methods are compared by showing the results of a simple analysis, together with a number of tests based on randomized…

Preffi 2.0 is an evidence-based Dutch quality assessment instrument for health promotion interventions. It is mainly intended for both planning and assessing one's own projects but can also be used to assess other people's projects (external use). This article reports a study on the reliability of Preffi as an external quality assessment…

The extent to which a scale score generalizes to a latent variable common to all of the scale's indicators is indexed by the scale's general factor saturation. Seven techniques for estimating this parameter--omega[hierarchical] (omega[subscript h])--are compared in a series of simulated data sets. Primary comparisons were based on 160 artificial…

The authors present a Markov Chain Monte Carlo (MCMC) parameter estimation procedure for the generalized graded unfolding model (GGUM) and compare it to the marginal maximum likelihood (MML) approach implemented in the GGUM2000 computer program, using simulated and real personality data. In the simulation study, test length, number of response…

Structural equation modeling (SEM) offers a flexible method for studying the patterns of interdependence in partners' behavior, which lie at the heart of interactions and relationships. Although SEM has been applied to the study of distinguishable dyads, in which partners are distinguishable by type, such as male and female, it has rarely been…

Little is known about researchers' understanding of confidence intervals (CIs) and standard error (SE) bars. Authors of journal articles in psychology, behavioral neuroscience, and medicine were invited to visit a Web site where they adjusted a figure until they judged 2 means, with error bars, to be just statistically significantly different (p…

The authors compare the operating characteristics of the bootstrap-F approach, a direct extension of the work of Berkovits, Hancock, and Nevitt, with Huynh's improved general approximation (IGA) and the Brown-Forsythe (BF) multivariate approach in a mixed repeated measures design when normality and multisample sphericity assumptions do not hold.…

Finding, accessing, and determining the credibility of information are skills most people would deem necessary for the college educated person, if not the average citizen, to possess today. At the same time, educators, as well as constituents of educational institutions are asking for better and more sophisticated assessment instruments of…

A latent variable modeling approach to reliability and measurement invariance evaluation for multiple-component measuring instruments is outlined. An initial discussion deals with the limitations of coefficient alpha, a frequently used index of composite reliability. A widely and readily applicable structural modeling framework is next described…

A new report published by the Buckeye Institute for Public Policy Solutions is a minor variant on six similar reports published by the Friedman Foundation over the past three years. The new report repeats some of the errors in the previous reports, and it follows a parallel structure, arguing that the costs of dropping out are dramatic for the…

This paper reports the findings of an experiment that investigated the reactions of Saudi college students to collaborative learning techniques introduced in two modalities: face-to-face and web-based learning. Quantitative data were collected with a questionnaire that examined the changes of three constructs: attitudes toward collaboration,…

M. J. Kolen, B. A. Hanson, and R. L. Brennan (1992) presented a procedure for assessing the conditional standard error of measurement (CSEM) of scale scores using a strong true-score model. They also investigated the ways of using nonlinear transformation from number-correct raw score to scale score to equalize the conditional standard error along…

The 1991 Survey of Recent College Graduates (RCG:91) is the sixth study in a series begun in 1976. The series provides data on the occupational and educational outcomes of recent bachelor's and master's graduates one year after graduation. The survey was conducted by Westat, Inc. in a two-stage sample involving 400 institutions of higher education…

Errors in item parameter estimates have a negative impact on the accuracy of item and test information functions. The estimation errors may be random, but because items with higher levels of discriminating power are more likely to be selected for a test, and these items are most apt to contain positive errors, the result is that item information…

R. J. Owen (1975) proposed an approximate empirical Bayes procedure for item selection in adaptive testing. The procedure replaces the true posterior by a normal approximation with closed-form expressions for its first two moments. This approximation was necessary to minimize the computational complexity involved in a fully Bayesian approach, but…