School Effects Indices: Stability of One- and Two-Level Formulations

Three residual-based methods for indexing school effectiveness were compared using data from elementary schools in Maryland. Two of the methods were regression-based procedures at the school level, and 1 was a hierarchical linear model approach, with Level 1 at the student level and Level 2 at the school level. The 2 methods were applied to a data source in which schools were evaluated separately at Grades 3 and 5 using 3 forms of a statewide performance assessment that were administered to randomly formed groups within each school. The hierarchical linear model approach had higher stability across test forms, but the stabilities of the 1-level formulations were almost as high. The authors concluded that 1-level approaches are viable alternatives when the added data necessary for the hierarchical linear model approach are unavailable.