It is shown that Cole's (1949) coefficient of interspecific association (C7) is biased in that it is influenced by the species' frequencies. The formulas given by Cole (1949) for the calculation of C7all can be written in the form: C7= ad — bc / °ad — bc° ° / Obs g2/Max g2° where a, b, c, and d refer to the four cells of a 2 x 2 contingency table. Obs g2is simply the value of g2associated with the observed values of a, b, c, and d. Max g2is the value of g2when a is as large (if ad ° bc) or as small (if ad