Evidence on Team-Based Teaching Models in Arizona

Strategic staffing models are scaling rapidly nationwide. We study the impacts of a team teaching model implemented in one large district in Arizona over several years. We exploit the staggered rollout over time in a difference-in-differences design to estimate effects on student test achievement. We find overall null impacts on student learning, but important heterogeneity by grade and subject. In particular, we find consistently positive effects on middle school math achievement across all specifications, but negative effects at the elementary level in some specifications. Across grades and subjects, teamed teachers also have significantly lower turnover rates and higher evaluation ratings, but the patterns of effects are not consistent with the achievement results. The student achievement findings are broadly consistent with the literature on teacher-level departmentalization and suggest that benefits to team teaching can emerge in contexts where teaming increases collaboration without disrupting established teacher-student relationships, such as in already-departmentalized middle school grades.