This paper is intended to function as both a major analytic effort and a review of the literature relevant to the establishment of an occupational information system. An introduction is followed by a summary of the legislative history documenting the process by which occupational information has been increasingly recognized as an essential element in the policymaking agenda. Section 3 outlines the conceptual foundations underpinning the use of occupational information. The section includes a discussion of alternative theories of the labor market, interventions that are appropriate in a theoretical context, and the data elements required to implement and monitor such interventions knowledgeably. Theories of vocational decisionmaking are discussed, and an attempt is made to place the need for labor market and occupational data in the context of vocational choice. Section 4 discusses the uses of occupational information for planners and guidance personnel. Anticipated and known benefits of data use in the decisionmaking processes of these user groups are addressed. The fifth section is devoted to the identification of specific data elements necessary in an ideal occupational information system. A conclusion and a bibliography end the paper. Appendixes are author recommendations for data elements for an occupational information system and an annotated bibliography. (YLB)