Composite scores are an exceptionally important psychometric tool for behavioral science research applications. A prototypical example occurs with self-report data, where researchers routinely use questionnaires with multiple items that tap into different features of a target construct. Item-level missing data are endemic to composite score…

The central messages of this paper are that (a) unequal variances may be more prevalent than typically imagined in educational and policy research, and (b) when considering tests of equal variances one needs to be cautious about what is being referred to as "Levene's test" because Levene's test is actually a family of techniques. Depending on…

A method is presented that eliminates some interpretational limitations arising from assumptions implicit in the use of arbitrary rules of thumb to interpret exploratory factor analytic results. The bootstrap method is presented as a way of approximating sampling distributions of estimated factor loadings. Simulated datasets illustrate the…

An experimental tool is described for the investigation of the human control behavior for slow responding dynamic systems. The Program for Research on Operator Control in an Experimental Simulated Setting (PROCESS) is a simulation of a dynamic water-alcohol distillation system that can be used in research on operator training. In particular,…

If manufacturing a safer cigarette is technically possible--an open question--then mandating that tobacco manufacturers improve the safety of cigarettes would likely have both positive and negative implications for the nation's health. On the one hand, removing toxins may reduce the incidence of smoking-related diseases and premature mortality in…