This report reviews and interprets activities carried out at the Center for Studies in Education and Development, Harvard Graduate School of Education, in support of the Information System for Vocational Decisions (ISVD) over a three year period. Included here are the contents, development, use so far, and potential of three specific datafiles within the system: (1) the Occupational Title File; (2) the Occupational Groups Datafile; and (3) the Military Datafile. The current limitations of the system are acknowledged. Besides the development and use of the three datafiles, the report also covers forecasts for two kinds of datafiles and discusses possible development of other datafiles and extensions of the existing ones. In each case the history of the work carried out during the Project is described and explained; its final results are presented; and suggestions are made for further development. (Author/TL)