Confidence intervals are widely accepted as a preferred way to present study results. They encompass significance tests and provide an estimate of the magnitude of the effect. However, comparisons of correlations still rely heavily on significance testing. The persistence of this practice is caused primarily by the lack of simple yet accurate…

Properties of the Spearman correction for attenuation were investigated using Monte Carlo methods, under conditions where correlations between error scores exist as a population parameter and also where correlated errors arise by chance in random sampling. Equations allowing for all possible dependence among true and error scores on two tests at…

Experimental research involves comparing two or more conditions. One of those conditions in single subject research is often the baseline. Adequate description of the baseline conditions is necessary for evaluating the effects of independent variables, drawing generalizations from studies, and providing information for subsequent replication…

This dissertation evaluates the impact of elementary school policies on child health behaviors and obesity in the United States. Two chapters address nutrition policies, two chapters address physical activity policies, and a final chapter estimates the health care cost savings associated with a decline in childhood obesity prevalence. The use of…

To support and promote secondary analyses, the International Association for the Evaluation of Educational Achievement (IEA) is making the SITES 2006 international database and accompanying User Guide available to researchers, analysts, and public users. The database comprises national contexts and school- and teacher-level data from 23 education…

A basic question of instructional interventions is how effective it is in promoting student learning. This paper presents a study to determine the relative efficacy of different instructional strategies by applying an educational data mining technique, learning decomposition. We use logistic regression to determine how much learning is caused by…

Methodological and political issues arise during the designing, conducting, and reporting of campus-climate studies for LGBT students. These issues interact; making a decision about a methodological issue (e.g., sample size) has an impact on a political issue (e.g., how well the findings will be received). Ten key questions that must be addressed…

Multiple matrix sampling is a sampling design in which both test items and examinees are randomly sampled from their respective populations. This study was designed to develop and assess a method for computing an estimate of a correlation coefficient when a multiple matrix sampling design is used. The examinee populations included 212 third-grade…

It is a false, but common, belief that statistical significance testing evaluates result replicability. In truth, statistical significance testing reveals nothing about results replicability. Since science is based on replication of results, methods that assess replicability are important. This is particularly true when multivariate methods, which…

The Likert rating scale procedure is often used in conjunction with a graded disagree-agree response scale to measure attitudes. Item characteristic curves associated with graded disagree-agree responses are generally single-peaked, nonmonotonic functions of true attitude. These characteristics are, thus, more generally consistent with an…

Considered the statistical comparison of groups under the condition of equal sample sizes. (Author)

A sampling theorem, based on the binomial probability distribution but otherwise distribution-free, is derived and some of its applications are illustrated numerically. (Author)