This paper compares the effects of desegregation on black achievement with the effects of other factors in the process of school learning that have recently been synthesized. The first section of the paper discusses techniques and guidelines for research synthesis, including meta-analysis. The second section presents a summary of the statistical analyses of research reviews of the 1970s and a collection of meta-analyses of the 1980s, which reveal the consistently potent productivity factors in school learning and which further illustrate techniques for research synthesis. The third section assesses selection criteria for studies of school desegregation and achievement and compares the effects of desegregation--as revealed by three recent meta analyses--with the effects of the educational productivity factors. It is concluded that the amount and quality of instruction, constructive classroom morale, stimulation in the home environment, and other such productivity factors are more effective in increasing black achievement than is school desegregation. (CMG)