Paul R. Yarnold
Optimal Data Analysis, LLC
A popular legacy index of association for 2×2 tables that is based on the odds ratio (OR), Yule’s Q=(OR–1)/(OR+1). Yule’s Q ranges between -1.00 and 1.00, with the value 0 indicating no association. Prior research assessing the association between voting behavior (0=not a voter; 1= voter) and the number of one’s organizational memberships (0=no memberships; 1=at least one membership) reported that Q=0.434, and “…the odds of voting among persons belonging to organizations (is) more than 2.5 times greater than the voting odds among those respondents without memberships” (p. 11). These data were analyzed using exploratory novometrics, treating voting behavior as a class variable and number of organizational memberships as an ordered attribute.