Paul R. Yarnold
Optimal Data Analysis, LLC
For an application involving two ordered attributes the chi-square four corner cells (CSFC) test is described as a “quick preliminary test” in lieu of factorial ANOVA. In this procedure a 2 x 2 contingency table is constructed using only the highest and lowest possible values of both measures: chi-square is used to obtain p, and phi to estimate the correlation between variables. The example used to illustrate this methodology violates two crucial assumptions underlying chi-square.