This article gives account of the construction process and subsequent implementation of the system of Chilean teachers´ performance assessment . Presents the complexity of the context in which it was developed, investigating on the major milestones and tensions that studied the debate between the three players who participated with their own educational visions and policies in the final design of this system, as were the Chilean Teachers College, the Ministry of Education and the Chilean Association of Municipalities. This paper describes also the main features of the system for evaluating educational performance, specifying what and how it evaluates, and the consequences that their results are evaluated for teachers. Finally poses a set of problems that have arisen in the process of its concrete implementation and they should face various challenges to consolidate power in his goal of enhancing the professional development of teachers.

Performance evaluation, professional development of teachers, knots problematic, participatory construction,negotiation.