All women face the threat of rape, forcing them to decide what to do to reduce their chances of being assaulted and how to defend themselves. A principal basis for such decisions should be women's estimates of the effectiveness of possible rape prevention and self-defense strategies. A questionnaire was administered to five groups of volunteer respondents: 41 women recruited through a university newspaper advertisement; 42 men recruited through the same advertisement; 40 women in support groups for parents of young children; 40 middle-aged university alumnae; and 47 sexual assault experts (38 females and 9 males) working primarily in criminal justice, victim assistance, or private consulting. Respondents were asked about the effectiveness of both rape prevention and self-defense strategies. All five groups judged prevention strategies to be highly effective, women more so than men and sexual assault experts. There was much greater variability in judgments for self-defense strategies, but respondent groups generally agreed with each other and with available statistical estimates of effectiveness. 19 references, 2 tables. (Author abstract modified)