Michael J. Stark, Ph.D., is the Director of Program Design and Evaluation Services for the Multnomah County Health Department and for Oregons Office of Disease Prevention and Epidemiology. Dr. Stark earned his Ph.D. in Clinical Psychology from U.C.L.A. and was a Professor of Psychology at Indiana University at South Bend and Lewis and Clark College before coming to work in public health. His research interests include evaluating public health programs and initiatives, especially the effectiveness of state-level tobacco control programs, prevention of HIV among high-risk populations, and the evaluation of substance abuse treatment programs. Examples of his work in tobacco control are studies of tobacco use among specific populations such as gays and lesbians and Latinos, impact of home smoking bans on quitting, and evaluations of components of state-level tobacco control programs including Quitlines and school-based programs. In HIV prevention, his work includes evaluation of community-level prevention programs, and studies to reduce HIV risk among out-of-treatment injection drug users, MSM and high-risk women. His recent work involved assessing the impact of clean indoor air exemptions and preemption on the prevalence of a tobacco-specific carcinogen among non-smoking bar and restaurant workers.