Tracking procedures in follow-up studies of drug abusers.

One of the problems that researchers frequently confront is the tracking and locating of research subjects. "Deviant" populations may present special difficulties in this regard. The experiences of a trained field survey unit doing drug-related research are examined. The tracking procedures which they developed are systematically presented. While the substantive focus is on doing research among drug abusers, many of the stated procedures are applicable to research on other deviant groups and, indeed, to all social groups.