Paul R. Yarnold
Optimal Data Analysis, LLC
Karl Pearson and George Yule debated the validity of the assumptions made when estimating the association between cross-classified vaccine (or antitoxin) administration and mortality, if both variables are assessed on binary measurement scales. Pearson assumed these measures reflect an inherently continuous distribution and used tetrachoric correlation to estimate their association, and Yule assumed these measures reflect an inherently discrete distribution and used the phi coefficient to estimate their association. Novometric statistical analysis (NSA) may be used in either circumstance: measurement scales may be treated as categorical or ordered, motivated by a priori substantive theoretical or empirical consideration; exploratory or confirmatory hypotheses may be tested; and observations may be analytically weighted.