The Phi Coefficient is a statistical measure used to assess the strength of association between two binary variables. It ranges from -1 to 1, where 1 indicates a perfect positive association, -1 indicates a perfect negative association, and 0 suggests no association. This coefficient is particularly useful in fields like psychology and sociology for analyzing categorical data. To calculate the Phi Coefficient, a contingency table is created, showing the frequency of occurrences for each combination of the two variables. The formula involves the product of the observed frequencies minus the expected frequencies, divided by the square root of the product of the total counts for each variable.