Teacher evaluation is essential for improving the individual performance of teachers and the collective performance of education systems. Designing teacher-appraisal methods is not easy, and requires the objectives of accountability and improvement to be carefully balanced. A crucial feature is what criteria teachers are appraised against, including, but not limited to, student performance. Also important are the degree to which teachers improve their professional skills and, crucially, the part they play in improving the school and system as a whole. In this way, evaluation and appraisal need to be well aligned with the process of system change. However, it is not enough to appraise the right things; the ways in which appraisal is followed through will determine its impact. At present, many teachers feel that appraisal has no or little consequence. School leaders need to become more skilled at using it intelligently, and evaluation needs to be more closely connected with career development and diversity. A specific issue is the extent and style of links between assessed performance, career advancement, and compensation. Whatever system is chosen, it must be well understood and transparently applied.