The Basic Education Development Index (Ideb) was created in 2007 and brings together, in a single indicator, the results of two equally important concepts for the quality of education: school flow and average performance in evaluations. It is calculated based on data on school approval, obtained from the School Census, and average performance in Inep's evaluations, the Basic Education Evaluation System (Saeb) – for the federative units and the country, and the Prova Brasil – for municipalities. Ideb adds to the pedagogical focus of the results of Inep's large-scale evaluations the possibility of synthetic, easily assimilable results that allow the setting of educational quality goals for systems. The index ranges from zero to ten, and the combination of flow and learning has the merit of balancing the two dimensions: if a teaching system retains its students to obtain better quality results in Saeb or Prova Brasil, the flow factor will be altered, indicating the need for system improvement. Conversely, if the system speeds up student approval without quality, the evaluation results will equally indicate the need for system improvement. Ideb is also important because it drives public policy in favor of education quality. It is the tool for monitoring the quality goals of the Education Development Plan (PDE) for basic education, which has established, as a goal, that by 2022 Brazil's Ideb will be 6.0 – an average that corresponds to an education system of quality comparable to that of developed countries.