The monograph presents a classification system of vocational rehabilitation program evaluation technology and literature intended to be useful for the efficient retrieval of program evaluation information and to provide greater communication among rehabilitation personnel. The classification system's purpose is to control the nuances of expression relevant to indexing and retrieving information, technology, and literature of interest to rehabilitation personnel and others concerned with program evaluation. The classification system includes: (1) a hierarchic outline consisting of 323 terms, which provides a systematic set of constructs for describing all the elements (environment, goals, resources, methodology, results, and utilization) that relate to the input, process, and output of program evaluation in the rehabilitation service system; and (2) an alphabetic thesaurus which includes all of the terms contained in the hierarchic outline as well as terms that refer a user to an accepted system term. Both the hierarchic outline and alphabetic thesaurus were developed in a manner that complements the existing Rehabilitation Service Administration's Research Information System Thesaurus. (Author/EC)