The Data and Statistics Core provides the personnel, expertise, and computational resources needed for maximum use of the data collected and analyzed by the investigators in the Program Project. It is responsible for oversight, quality control, and integration of data preparation, data management, statistical model building, and other data analysis across all projects. It also takes the lead in preparing and disseminating the numerous shared data sets and facilitating their use by individual projects, as well as data archiving and code book creation and maintenance. Core B's primary function will be an integrative one, with a primary goal of producing efficiency and synergy across projects by developing methods and sets of data that take advantage of the parallels in measures, hypotheses, and analytic needs of the research projects. Core B has three Specific Aims. The first aim is to create, integrate, and manage data sources across projects. Core B has responsibility for collecting and preparing the major data sets that will be used across projects and for monitoring the progress of data collection and analysis in each of the projects and will advise each project on data use and quality issues. The Core will construct program-wide data sets on a regular basis and publish these internally along with related manuals and other utilization products. The second aim is to create novel data sets using the "raw" data sets compiled as part of Specific Aim 1. These raw data sets will be modified and embellished so as to make them more useful and easily integrated with other data sets within the Core and across the Program Project. The third aim is to advise the research project investigators on both standard and newly developed analytic techniques and models relevant to the study of networks and neighborhoods, thus ensuring methodological rigor across projects. Thus, the Data and Statistics Core will provide computational and statistical support for research design and modeling matched to the hypotheses under investigation in each of the projects. The Core is responsible for maintaining common data sets, providing statistical consulting services to each project, conducting statistical analyses required for studies involving multiple projects or requiring special-purpose software or expertise, and creating novel data sets that broaden the analytic possibilities for data held by the Core.