Avalia？？o educacional e modelos de valor acrescentado: tópicos de reflex？o

since the beginning of the 21st century that we face a growing wave towards the implementation of educational evaluation systems with high-stake accountability purposes at the level of teachers and schools. the development and implementation of such systems is quite fast, either in terms of the influence of the educational evaluation on public policies, or in terms of the public policy evaluation. in this context, the use of the value-added concept is consensually accepted. this paper presents some reflections on its implementation and use, emerging themes such as the model choice, school and student outcomes, and its appropriateness by practitioners. in addition, some examples are given where the misuse of performance indicators had adverse consequences to education.