In this article, the authors discuss the role of performance evaluation in the context of public administration, its peculiarities, challenges, difficulties and limits. To this end the authors start by presenting a theoretical framework on the development of Performance Evaluation as a concept of organizational intervention, and go on to discuss the case of the Portuguese public administration and the creation of the SIADAP model (Integrated Performance Assessment for Public Administration) that is been applied over the past six years. Keywords: Public Administration, Performance, Evaluation, Portugal

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