This paper reviews and synthesizes the available literature concerning the effects of intervention programs at the secondary and higher educational levels. In achieving an understanding of the design of these efforts it is important to recognize that the first projects, e.g. the Demonstration Guidance Project, Higher Horizons, established a virtually universally followed model of educational intervention which: (1) employed a "deficit" model to account for differential rates of academic achievement; (2) offered supportive educational services; (3) worked with a segment of the "disadvantaged" population; and, (4) concentrated on the development of reading and mathematical skills. While most of the studies considered possess serious methodological weaknesses, the resulting evidence nevertheless suggests that the projects have increased the numbers of students graduating from high school and applying to, enrolling in, and graduating from college. The findings also indicate some positive impact in the areas of academic values, attitudes and motivations. But neither the gap in academic achievement between "disadvantaged" and "advantaged" students nor the academic achievements of participating students relative to non-program students from similar backgrounds seems to have been affected. (Author/JM)