The purpose of "What Works in Reading?" was to identify the factors that contribute most strongly to achievement growth in reading. The study, which investigated fourth graders in 25 schools, was run jointly by the Philadelphia School District and the Federal Reserve Bank of Philadelphia, and the respect and understanding that developed between the two groups were basic to the study's implementation. Information was collected and computerized in five categories: the individual child and each child's principal, classroom teacher, reading teacher, and school. The results of 500 multiple regression equations identified variables in each of the five categories (15 in all) that made a difference in reading. Certain variables considered important in the past were found not to affect achievement. The study became news immediately. Perhaps its major impact was on the school district's "A Blueprint for Academic Achievment," 10 of whose specific recommended actions flowed directly from the research report, with an equal number at least tangentially related. Unlike many studies, "What Works in Reading?" has had an impact. While the extent of the impact and the ultimate level of utilization remain to be seen, the study has succeeded as a catalyst for change where other such efforts have failed. (CMG)