In a study of reading achievement in the Chicago schools, regression and factor analysis were used to discover which school measures were associated with the reading comprehension scores of students ages 7, 10, and 13. Achievement data from three successive years (1974-75, 1975-76, and 1976-77) were averaged from the results of the Iowa Tests of Basic Skills. Results indicated that when the data from all of the schools were combined several implications were apparent: attendance, amount of money spent per pupil, the smaller size of the school, and the amount of teacher education all counted toward the achievement gains of students. In the primary grades, gains in reading achievement increased as the log of the percent of poverty in the community declined and as the level of poverty decreased. The percent of whites in a school was next highest to level of poverty as a predictor of reading achievement gains. The highest predictor of achievement gains in the intermediate and upper grades was the achievement level score obtained at age ten. (MKM)