PIP: The AIDS epidemic and the associated discovery of HIV brought attention to the dearth of knowledge among social scientists about homosexuality, bisexuality, injectable drug use, and other behaviors which may place participating individuals at risk of contracting and/or transmitting HIV. To redress these gaps in their knowledge, researchers have recently tended to gather attitudinal and behavioral data through population-based KAP-style surveys and to make inferences from such data to the current prevalence and future course of the AIDS epidemic. While survey data may help expand our knowledge on the distribution of practices in a variety of populations, it is not clear that they help us understand the epidemiology of AIDS in a given population. The author argues that these unfocused inquiries into diffuse behaviors in undifferentiated populations are not productive in low-seroprevalence populations, especially when the objective is to design interventions to avert further infection. The failure of KAP surveys to distinguish conceptually between the relevance of AIDS-related behavioral data for individuals and for populations makes them fundamentally flawed for such purposes. An illustration of the AIDS epidemic in Santiago, Chile, is used to substantiate this argument and an alternative perspective is presented based upon interviews with people with AIDS and a survey of current HIV-surveillance and blood screening programs. KAP survey findings generally lead to prescriptions for mass behavior modification. Individuals infected with HIV who remain sexually active and their partners should instead be targeted by interventions to change their behavior. This approach would focus on actual social and sexual networks and the true etiology of viral contagion. In closing, the author acknowledges that his proposed approach may unjustly stigmatize or blame certain groups; contribute to a lack of unity in the fight against the virus and jeopardize supportive funding and legislation; and create a false sense of security for individuals not in the targeted risk groups.