The traditional points system and subsequent Grade Point Average (GPA) in education perpetuates an evaluation of academic performance which reflects arbitrary weighting of assignments and/or assessments. As such, GPAs which are calculated using a traditional points system are not unidimensional in their design. The baseball batting and slugging…

Structural equation modeling (SEM) and path analysis using composite-scores are distinct classes of methods for modeling the relationship of theoretical constructs. The two classes of methods are integrated in the partial-least-squares approach to structural equation modeling (PLS-SEM), which systematically generates weighted composites and uses…

This Monte Carlo simulation study compares methods to estimate the effects of programs with multiple versions when assignment of individuals to program version is not random. These methods use generalized propensity scores, which are predicted probabilities of receiving a particular level of the treatment conditional on covariates, to remove…

I discuss three common practices that obfuscate or invalidate the statistical analysis of randomized controlled interventions in applied linguistics. These are (a) checking whether randomization produced groups that are balanced on a number of possibly relevant covariates, (b) using repeated measures ANOVA to analyze pretest-posttest designs, and…

There is currently a considerable diversity of quantitative measures available for summarizing the results in single-case studies. Given that the interpretation of some of them is difficult due to the lack of established benchmarks, the current article proposes an approach for obtaining further numerical evidence on the importance of the results,…

The purpose of this study was to evaluate the effectiveness of group testing as a pedagogical technique to enhance learning in a difficult subject such as statistics. Individual test scores were compared to their group test scores for the same, identical test. A t test was used to compare the scores for 157 randomly selected MBA students enrolled…

We explain how to simulate both univariate and bivariate raw data sets having specified values for common summary statistics. The first example illustrates how to "construct" a data set having prescribed values for the mean and the standard deviation--for a one-sample t test with a specified outcome. The second shows how to create a bivariate data…

In January 2009, in the last week of the Bush Administration, the U.S. Department of Education (ED), upon orders from the departing political appointee staff, published the final report in a long running National Evaluation of Upward Bound (UB). The study was conducted by the contractor, Mathematica Policy Research. After more than a year in…

A method is presented for investigating two aspects of the sensitivity of a linear composite to the values of its weights. A composite very similar to the original can be produced by weights very different from the original weights. (SLD)

A strategy is described for comparing and weighting student marks on separate performance elements on the basis of statistical analysis and teacher judgment. Differences between nominal and effective weightings are discussed. (MSE)

Given "T" joint observations on "K" variables, it is frequently useful to consider the weighted average or scaled score. L-scaling is introduced as a technique for determining the weights. The technique is so named because of its resemblance to the Leontief matrix of mathematical economics. L-scaling is compared to two…

A study investigated the effectiveness of a weighting procedure for adjusting survey results to correct for nonresponse bias. Using data from a Cooperative Institutional Research Program followup survey, results indicate that the procedure is highly effective in univariate distributions; its effectiveness in adjusting correlation and regression…

Recent developments in cognitive and educational psychology, such as increased appreciation of the situated nature of learning and understanding, call for broader ranges of student models and types of data than those standard in testing today. We must specify how what we observe on the test is related to competence as we conceptualize it, and…

A statistical comparison of Medical College Admission Test scores with National Board of Medical Examiners (NBME) Part I scores of one school's students supported simple averaging of subtest scores rather than weighting as a predictor of NBME Part I performance. Similar results were obtained using basic science course examination scores. (MSE)