The School-wide Evaluation Tool (SET) is a commonly used measure of the implementation fidelity of school-wide positive behavior interventions and supports (SWPBIS) programs. The current study examines the content and concurrent validity of the SET to establish whether an alternative approach to weighting and scoring the SET might provide a more accurate assessment of SWPBIS implementation fidelity. Twenty published experts in the field of SWPBIS completed online surveys to obtain ratings of the relative importance of each item on the SET to sustainable SWPBIS implementation. Using the experts' mean ratings, four novel SET scoring approaches were developed: unweighted, reweighted using mean ratings, unweighted dropping lowest quartile items, and reweighted dropping lowest quartile items. SET 2.1 data from 1,018 schools were used to compare the four novel and two established SET scoring methods and examine their concurrent validity with the Team Implementation Checklist 3.1 (TIC; across a subsample of 492 schools). Correlational data indicated that the two novel SET scoring methods with dropped items were both significantly stronger predictors of TIC scores than the established SET scoring methods. Continuous SET scoring methods have greater concurrent validity with the TIC overall score and greater sensitivity than the dichotomous SET 80/80 Criterion. Based on the equivalent concurrent validity of the unweighted SET with dropped items and the reweighted SET with dropped items compared to the TIC, this study recommends that the unweighted SET with dropped items be used by schools and researchers to obtain a more cohesive and prioritized set of SWPBIS elements than the existing or other SET scoring methods developed in this study. / School Psychology