G oodman– K ruskal Measures of Association
GRAHAM J. G. UPTON · Encyclopedia of Biostatistics · 2005
Abstract The measures of association proposed by Goodman and Kruskal between 1954 and 1972 can all be described as proportional reduction in error (PRE) measures. They describe the association between two categorical variables in terms of the increase in the probability of correctly predicting the category of one variable when information is supplied about the category of the other variable. The measures λ and τ are for use with any categorical variables, whereas the measure γ is for use when both variables are ordinal.