This paper serves as an introduction and background for the remaining papers in this issue, which describe in somewhat more detail the major pieces in the Army's Selection and Classification Project (Project A). The principal objectives, the methods being used, and the basic research design of Project A are outlined. Project A was a 7-year effort conducted by the Army Research Institute and a consortium of three research firms. The overall objective was to generate the instrumentation and validity information data base that are necessary for modeling and developing an organization-wide selection and classification system. Both the scientific and practical implications of the project are noted.