This brief reviews the publicly available principal assessments and points superintendents and policy makers toward strong instruments to measure principal performance. Specifically, the measures included in this review are expressly intended to evaluate principal performance and have varying degrees of publicly available evidence of psychometric testing. The review of this information is intended to inform decision makers' selection of job performance instruments used for hiring, performance assessment, and tenure decisions. This brief also addresses the importance of standards-based measures, the need for establishing reliability and validity, and the measures that are more widely accepted and psychometrically sound. (Contains 1 table and a list of additional resources.)