Learn how to conduct an ANCOVA in R using Type III sums of squares to evaluate group differences while controlling for covariates. This tutorial walks through model assumptions, and contrast coding  for Type III ANCOVA analysis in unbalanced designs. Using a simulated example, we investigate the relationship between Southern California women’s attitudes toward prescription drug use and religious affiliation and employment status while controlling for mental well-being, physical health, and the number of current prescriptions.
