Phi/Phimax: Review and Synthesis
Ernest C. Davenport, Nader A. El-Sanhurry · Educational and Psychological Measurement · 1991
This paper explores the phimax adjustment to phi. It shows phi/phimax to be a measure of relationship apart from its affiliation with phi. The adjustment when the variables are inversely related, phimin, is also considered. Next is a discussion of the relation between phi/phimax and kappa. The article ends with an analytical look at phi/phimax. Some findings of this exploration are: phi/phimax is an asymmetrical, equal-interval step function with ties to probability. Finally, phi/phimax is shown to be nonrobust in situations where it should be most useful.