Type III Sums of Squares

Select to print the Type III Sums of Squares. Researchers implementing an experimental design frequently lose experimental units and find themselves with unbalanced, but complete, data. The data are unbalanced in that the number of replications is not constant for each treatment combination; the data are complete in that at least one experimental unit exists for each treatment combination. In this type of circumstance, an experimenter may find the hypotheses tested by Type III sum of squares are of more interest than those tested by Type I (sequential) sum of squares, and the adjusted means of more interest than unadjusted means.