The phi correlation coefficient (phi) is one of a number of correlation statistics developed to measure the strength of association between two variables. The phi is a nonparametric statistic used in cross-tabulated table data where both variables are dichotomous. Dichotomous means that there are only two possible values for a variable. As an example, the variable addressing life has only two levels, “alive” and “not alive” (or dead). So if a public health department was researching the proportion of newborns born alive versus born dead, each baby could be born alive or born dead; there are no other possibilities. Typically, such data are coded numerically for the computer. One level of the variable can be assigned the number 0 and the other level is assigned ...