The authors empirically examined whether the validity of a residualized dependent variable after covariance adjustment is comparable to that of the original variable of interest. When variance of a dependent variable is removed as a result of one or more covariates, the residual variance may not reflect the same meaning. Using the pretest-posttest…

The present authors argued that the covariance analysis is completely valid even if there is a true main effect for pretesting and a second point of the paper involved a recommendation for data analysis if the interaction from ANOVA was significant. (Editor/RK)

The effects of student teaching and the pretesting of attitudes on student teachers' attitudes were studied. Results suggested that pretesting of attitudes was detrimental to attitude improvement. Appropriate designs for assessing changes in attitudes were discussed. (Author/MH)