I have been working on English as a Foreign Language teacher performance evaluation. I have studied teacher evaluation systems of many countries. In many of them school principals are in charge of evaluating foreign language teachers' performance. However, in many contexts, school principals may not know the foreign language well.
Given that the main purposes of teacher evaluation are teacher professional development and quality assurance, I want to know the feedback of others on this issue. Do you think that school principals’ evaluation of foreign language teachers' performance (while they may not be competent enough in that language) can lead to teacher professional development or assure quality? Or this practice should be changed?