The document studies the availability and use of manpower data in vocational education and delineates the underlying factors influencing data usage. Information was collected from 10 States selected from 10 Federal regions. Descriptions of the findings are presented for each agency according to the following categories: (1) State vocational education agencies; (2) local vocational education agencies; (3) State and local employment security agencies; and (4) regional offices of the United States Office of Education, Bureau of Labor Statistics, and Manpower Administration. Exemplary practices at the State and local levels are listed and include organizational relationships between employment service and vocational education agencies, special services provided by employment security agencies, and innovative uses of manpower data by vocational educators. Factors influencing the availability and use of manpower data are identified: student demand, personal knowledge, local autonomy, agency isolation, and revenue-sharing. Recommendations for improving the availability and use of manpower data are presented for the Congress, Commissioner of Education, Commissioner of Labor Statistics,, and Assistant Secretary of labor for Manpower. References are included. Appended materials include the methodology, the occupational employment statistics program, and a copy of the Interagency Agreement for the Development of Occupational Manpower Information. (Author/EC)