Under this procurement an occupational referent population data base consisting of data from studies completed by the National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH) is to be assembled. A software system will be developed to produce referent population data in formats suitable for the Monson, OCMAP, and NIOSH packaged analytic programs. Data from each study group to be included in the system will be edited and converted to a standardized format. Information collected on study groups will be combined, and a software system will be developed to allow investigators at NCI and NIOSH to obtain referent population rates by race and sex for the entire data base or for designated subsets by study population, geographic region, and other variables. The system must be user-friendly so that investigators who have little or no computer background may use it. When the system has been developed and adequately tested, it will be made available on-line to investigators at NCI and NIOSH. The first two years of the contract of which the above-mentioned period of performance is Year 1 will be devoted to development of the computer software, converting, recording, and merging datasets into a large master file, testing and debugging the system, and drafting the documentation.