main_effects
ANOVA
Specification
Alias: None
Arguments: None
Default: No main_effects
Description
The main_effects
control prints Analysis-of-Variance
main effects results (e.g. ANOVA tables with p-values per variable).
The main_effects
control is only operational with the
orthogonal arrays or Latin Hypercube designs, not for Box Behnken or
Central Composite designs.
Main effects is a sensitivity analysis method which identifies the input variables that have the most influence on the output. In main effects, the idea is to look at the mean of the response function when variable A (for example) is at level 1 vs. when variable A is at level 2 or level 3. If these mean responses of the output are statistically significantly different at different levels of variable A, this is an indication that variable A has a significant effect on the response. The orthogonality of the columns is critical in performing main effects analysis, since the column orthogonality means that the effects of the other variables “cancel out” when looking at the overall effect from one variable at its different levels.