The incidence of patients enrolled in the National Institutes of Health (NIH) Clinical Center trials who have sought and/or are currently receiving adjunctive unconventional therapies is not known. Because NIH is a research facility, it is particularly important to know of an individual's use of any prior or ongoing alternative medicine therapies that may have an impact on medical care and research results. This study will use interviews to objectively document the prevalence, demographics, and patterns of use of alternative medical therapies. The study population will be 250 adult patients diagnosed with cancer and 250 HIV patients diagnosed positive with HIV who are on Clinical Center, NCI, and National Institute of Allergy and Infectious Diseases protocols. A simple descriptive survey design will be used. The instrument is a modification of surveys developed by Barrie Cassileth, Ph.D., and David Bisenberg, M.D. Mso incorporated is the multidimensional Health Locus of Control Scale modified by Dean Kazoleas, Ph.D. Currently 100 patients (73 cancer and 27 HIV) have been interviewed.