Use multi-vari charts as preliminary tools to "look" at the data. Multi-vari charts present analysis of variance data graphically, providing a visual alternative to analysis of variance. Multi-vari charts are useful in understanding interactions.

Minitab draws multi-vari charts for up to four factors.

A laboratory is doing a preliminary study on a new variety of corn that may require less fertilizer than other varieties. They are interested in determining the relationship between Variety and amount of Fertilizer and its effect on Yield. The two factors are Variety and Fertilizer; the response is Yield.

Data: Fertilizer.MTW (available in the Sample Data folder).