Analysis of Covariance (ANCOVA) is robust with respect to dual violations of the assumptions of equal regression slopes and normality of distributions provided that group sizes are equal, but displays disruptions of empirical significant levels when unequal regression slopes and unequal group sizes are coupled with nonnormal distributions.…

A statistical test for analysis of repeated measures is presented. It is shown that an appropriate chi-square statistic can be computed for related measures by taking account of the covariance among trials in computing a variance for the chi square statistic. (Author/JKS)

Using computer simulation, parametric analysis of covariance (ANCOVA) was compared to ANCOVA with data transformed using ranks, in terms of proportion of Type I errors and statistical power. Results indicated that parametric ANCOVA was robust to violations of either normality or homoscedasticity, but practiced significant power differences favored…

Five distribution-free alternatives to parametric analysis of covariance (ANCOVA) are presented and demonstrated using a specific data example. The procedures considered are those suggested by Quade (1967); Puri and Sen (1969); McSweeney and Porter (1971); Burnett and Barr (1978); and Shirley (1981). The results of simulation studies investigating…

Five distribution-free alternatives to parametric analysis of covariance are presented and demonstrated: Quade's distribution-free test, Puri and Sen's solution, McSweeney and Porter's rank transformation, Burnett and Barr's rank difference scores, and Shirley's general linear model solution. The results of simulation studies regarding Type I…

A content analysis was conducted of three educational research journals published by the American Educational Research Association to review the quantitative and qualitative techniques used in educational research. All articles appearing in these three journals from 1988 through 1995 (total n=1,715) were considered. Research methods were…