Promotional examinations are held at all levels except in grades 6 and 9 at the basic education level and grade 12 in the secondary stage, which apply standardized regional or national exams. The Ministry of Education is responsible for making decisions about the education system with the support of three Centers: the National Center of Curricula Development, the National Center for Education Research, and the National Center for Examinations and Educational Evaluation. Each center has its own focus in formulating education policies with other state-level committees. On the other hand, the Ministry of Higher Education supervises the higher education system.