Stability of School-Level Scores From Large-Scale Student Assessments

More attention is being given to evaluating the quality of school-level assessment scores due to their importance for school-based planning and monitoring effectiveness. In this study, cross-year stability is proposed as an indicator of data quality and the degree of stability that is appropriate for large-scale assessments of student performance is explored. Following a search of Internet sites, Year 1 to Year 2 stability coefficients were calculated for assessment data from 21 states and 2 provinces. The median stability coefficient was .78 in mathematics and reading, but coefficients for writing were generally lower. A stability coefficient of .80 is recommended as the standard for large-scale assessments of student performance. A high degree of cross-year stability makes it easier to detect and attribute changes in school-level scores to school improvement efforts. The link between stability and reliability and several factors that may attenuate stability are discussed.