Most of the social science research is based on the implied assumption that measurement error is the same across key socio-demographic groups and all differences in key statistics of interest are real. Nevertheless, there is evidence that this is not the case. In this paper, the authors tackle this important topic by investigating if data quality…

The data collection of a cohort study requires making many decisions. Each decision may introduce error in the statistical analyses conducted later on. In the present study, a procedure was developed for estimation of the error made due to the composition of the sample, the item selection procedure, and the test equating process. The math results…

In this paper, we respond to the criticisms and concerns raised by D.V. Cicchetti, A.S. Kaufman, & S.S. Sparrow (this issue) in their review of the PCB literature, with particular attention to our own research in Michigan. We agree that multiple comparisons and functional significance are issues that would benefit from more discussion.…