PIP: This is a comment on the models created by researchers concerning contraceptive failure and unintended pregnancy. Human behavior refuses to conform to the models due to the occurrence of some unusual events. Thus, the models should be used with caution. Both unintended pregnancies and contraceptive failures are more complex than they appear at first glance. Part of the problem resides in the history of the instrument used to measure unintended pregnancy. Becoming accidentally pregnant presents people the oppressing responsibility of having to decide whether to enter into parenthood or not. The choices about parenthood are problem-filled in this country. As a consequence, the processes that determine the intimate lives of couples and in the culture as a whole should be studied. Otherwise, the industrialized world will have to put up with contraceptive "accidents", while political movements will continually promise to resolve these complexities.