The paper provides the basic concepts and structure of an evaluative-management information system that meets the needs of vocational rehabilitation program and project managers and allows inter- and intra-program and project comparisons. Cost-benefit analysis has not (1) provided managers with relevant information upon which to base their decisions, (2) provided a systematic means for making tradeoffs, nor (3) helped managers develop consistent incentives and standards to measure internal project efficiency. Three major factors must be agreed upon before developing an evaluation system: quantifiable program objectives, benefit-cost framework, and a control group to be used as a standard for estimating gains in client income attributable to the program. Som problems to be considered in structuring mathematical models are estimating client income gain and using a national labor market survey as a statistical control. The mathematical relationship between sample survey mean, sample survey size, and the prediction of foregone income for single clients and aggregations of clients influences the prediction variance. The new design for a national longitudinal survey is a continuous work history survey based on calendar months which allows for complete recording of single employment, multiple employment, job search, training, and withdrawals from the labor force. (SAuthor/AG)