Evaluates the current R-3 program to raise reading and arithmetic achievement levels in a disadvantaged San Jose junior high school, and presents a cost model to enable the decisionmaker to explore cost consequences of program variations as an aid to future planning. The model translates required resources into dollar costs by taking into account program components, resources, and resource costs. Students with lowest entering scores gained eight months' achievement during the four-month program. Students' average achievement gain in reading was five months; in arithmetic, three months. Program expansion left unchanged the original concepts of motivational activities, intensive involvement, individualized reading and arithmetic, and parental involvement. Major changes included heterogeneous grouping, a new hour of humanities instruction, reduced expenditures for R&D, increased expenditures for teachers, and fewer field trips. Suggestions for program improvement were made in the areas of program coordination, student orientation, facilitation of achievement gain, and restructuring of intensive involvement. 170 pp. Ref.