Many students of statistics and econometrics express frustration with the way a problem known as "bad control" is treated in the traditional literature. The issue arises when the addition of a variable to a regression equation produces an unintended discrepancy between the regression coefficient and the effect that the coefficient is…

This study applies a procedure which yields estimates of true score change on the Scholastic Aptitude Test (SAT) adjusted for regression effects and student self-selection. It is shown that student self-selection in deciding to repeat an admissions test probably involves factors in addition to the measurement error attributable to variations in…

Covariance structure modelling is applied to the problem of estimating reliability and measurement error in survey data. To provide a basis for grouping certain question or variable types (data from questions), a simple typology based on the formal characteristics of the questions is outlined. From this classification, models for the different…

Classification studies are important for practitioners who need to identify individuals for specialized treatment or intervention. When interventions are irreversible or misclassifications are costly, information about the proficiency of different classification procedures becomes invaluable. This study furnishes information about the relative…