This paper describes a planning cost model for estimating the comparable replication cost of an educational program for use in evaluating alternative programs and planning future programs. The conceptual and methodological bases of cost analysis are explored and the shortcomings of present methods for comparison and evaluation of educational programs are described. The proposed model presents a framework for bringing together the resources (facilities, staff, equipment, and materials) required to carry out an educational program and for relating these resources to program output in the form of activities. These relationships provide information on the relative merits of selected changes in the activity structure of a total program, and on the cost consequences of changes in the resource utilization rate or in resource cost. Comparable replication costs for several different programs are estimated to illustrate the use of the model. (Author)