This report summarizes the design strategy and preliminary conclusions from the first year of a study that attempted to identify educational factors that produce the differences in student achievement between unusually high-performing schools and unusually low-performing schools of similar socioeconomic characteristics. The sample included 21 pairs of schools from throughout California. Data were collected through questionnaires, interviews, and observation of ten teachers and the principal of each school studied. Among the most evident findings was the importance of teacher perception of administrative support. The presence of a well-defined agreement and understanding between teachers and principals regarding the locus of responsibility and authority at higher-achieving schools was noted. The study also noted very different classroom behaviors exhibited by teachers in higher-achieving schools and different grouping practices between higher- and lower-achieving schools. Furthermore, higher-achieving schools reported spending more time on social studies instruction and less time on mathematics. (Author/JG)