Dr. Kirk Dombrowski, Associate Professor of Anthropology at CUNY - Hidden and hard-to-reach populations represent critical challenges for social scientists interested in issues of social well-being. Recent epidemiology has shown that even small populations can have a disproportionate influence on public health, even while remaining invisible to conventional research techniques. Methamphetamine users in New York City represent such a population, with high levels of risk for injection and sex-related diseases and unknown interaction with surrounding populations. And like many hard to reach populations, the stigma associated with drug use has made the population largely resistant to participation in research, even when that research is aimed at addressing their own health needs. This lecture will discuss the use of social network-based methods to recruit NYC Meth users, and how data related to recruitment can be combined with sociological and ethnographic perspectives to better understand local market dynamics, market topology, and even to produce a rigorous population estimate.