Respondent attrition is a common problem in national longitudinal panel surveys. To make full use of the data, weights are provided to account for attrition. Weight adjustments are based on sampling design information and data from the base year; information from subsequent waves is typically not utilized. Alternative methods to address bias from…

Multivariate analysis of variance (MANOVA) is widely used in educational research to compare means on multiple dependent variables across groups. Researchers faced with the problem of missing data often use multiple imputation of values in place of the missing observations. This study compares the performance of 2 methods for combining p values in…

The authors argue that a parameterization in terms of cell means is a useful conceptual device for resolving problems inherent in the nonorthogonal analysis of variance. They demonstrate their argument by considering two widely-used methods for testing main effects. (Author/BW)

An evaluation of open education was shown to produce misleading results due to probable regression phenomena. These questionable results are now spread throughout the literature of education, sociology, and psychology. Researchers are advised to review, not merely summarize, prior articles. (Author/PN)

Presents a method for the collection and analysis of collateral data about research subjects (i.e., measurements of events in subjects' lives that may affect outcome measures and/or lead to attrition). A six-step procedure evaluates bias resulting from subject attrition from a study using data from lost and retained subjects. (SLD)

This poem, with stanzas in limerick form, refers humorously to the many threats to validity posed by problems in research design, including problems of sample selection, data collection, and data analysis. (SLD)

Within-class regression is a method, developed in this paper, of comparing a large number of nonequivalent groups. This study indicated that within-class regression was a less biased method of data analysis and will yield more accurate estimates of treatment effects than analysis of covariance. (PN)