Overview for Balanced ANOVA

Use Balanced ANOVA to fit least squares models and determine whether the means of two or more groups differ when you have categorical factors and a continuous response. The design must be balanced unless you have a one-way design. A balanced design has the same number of observations for each treatment combination. The model can include interaction terms, crossed and nested factors, and fixed and random factors.

For example, a company wants to determine whether operator, machine setting, and shift affects the viscosity of a coating substance. The design is balanced because all combinations of operator, setting, and shift have the same number of observations.

If you receive a warning that the data are unbalanced, you can perform cross tabulation to determine the number of observations for each factor level combination.