Ideally, performance evaluation considers aspects of reliability (psychometric), validity and authenticity.
Lyle Bachman at UCLA is one of the leading experts in performance evaluation reseach and language testing in general.
While performance evaluation has been successful in evaluating reading comprehension performance, difficulties arise in evaluating speaking, listening and writing skills which are weightier aspects of the goal of language learning, communicative competence. As a result, a balance of performance evaluation and competency evaluation is often called for by language teachers.