Measuring and evaluating school performance: an investigation of status and growth-based achievement indicators.

Several school performance indices were evaluated using achievement data from multiple longitudinally matched middle school student cohorts in a large district in the southwestern United States. Measures designed to index the within-cohort achievement status and growth of students as well as the status and growth-based changes that occur over years between different student cohorts were studied. Within- and between-cohort status and growth-based estimates of school performance were generated by applying simple and relatively complex statistical models to the longitudinal time-series data obtained on students. Results indicated that within-cohort status-based estimates were closely related to student demographics and between-cohort estimates were associated with cohort enrollment size and initial performance level. These results suggest that schools may often be rewarded and penalized on the basis of factors over which school personnel have limited or no control. Implications for the measurement and evaluation of school performance are discussed.