The Phi-coefficient, the Tetrachoric Correlation Coefficient, and the Pearson-Yule Debate - eScholarship

Two measures of association for dichotomous variables, the phi-coefficient and the tetrachoric correlation coefficient, are reviewed and differences between the two are discussed in the context of the famous so-called Pearson-Yule debate, that took place in the early 20th century. The two measures of association are given mathematically rigorous definitions, their underlying assumptions are formal…