DESCRIPTION: (Applicant's Description) The Measures and Methodology Core (M&M) will establish a set of high quality core measures and assessment methods (those that cut across research projects that measure key constructs of the conceptual models examined within the TTURC. This will include conducting pilot work within the first six months of the TTURC to develop a measure of lifetime smoking patterns and to finalize interview and self-report assessment procedures. Measures and Methodology investigators will insure the fidelity and integrity of all assessment procedures conducted within the TTURC. This will include: a) providing clinical training and supervision to assessment interviewers in the conduct of the core assessment protocol, b) conducting ongoing assessments of interviewer reliability for all interviewers measures, c) regularly monitoring the quality of data collected on all projects, and d) coordinating the collection and preservation of blood samples across studies. As part of their TTURC involvement,the investigators will develop and evaluate innovative new methods to inform research in nicotine dependence. This will include: a) establishing the reliability and validity of a novel methodology for the assessment of lifetime smoking patterns, including trajectories of smoking uptake and cessation, b) developing improved, multidimensional measures of nicotine dependence, c) conducting secondary analyses using progression to nicotine dependence (Project 2), and difficulty quitting smoking (Project 3), d) applying cost-effectiveness models to treatment outcomes and risk analyses within the TTURC, and e) developing strategies to assess possible sources or error variance due to sampling and response biases. Investigators of this core will also provide ongoing monitoring of the scientific literature to inform the TTURC about new developments in measurement and methodology related to the assessment of nicotine dependence and related constructs. Finally, we expect that the M&M will serve as a resource for consultation on both a local (within the TTURC) and national level regarding issues of assessment, methods development and methodology in conducting nicotine dependence research.