Balanced ANOVA Design

An ANOVA design is a balanced ANOVA design when all cells in the ANOVA design have equal N, when there are no missing cells in the design, and, if nesting is present, when the nesting is balanced so that equal numbers of levels of the factors that are nested appear in the levels of the factor(s) that they are nested in. Most between-groups ANOVA designs can be analyzed much more efficiently when they are balanced ANOVA designs. STATISTICA GLM contains an option to "instruct" STATISTICA that the design is balanced, and that the more efficient computational methods can be used. Even very large designs with effects with degrees of freedom in the hundreds can thus be analyzed in mere seconds, while the general computational procedures (that do not assume a balanced design) may take several minutes to accomplish the same. See the Efficient computations for (huge) balanced ANOVA designs topic in the GLM Introductory Overview for additional details.