Although the government reintroduced the study of religion into the public school curriculum from primary grades through college, it did not act to alter the basic organization of the education system. Thus, as late as the school year 1986-1987, schools had not changed significantly from the pattern prior to the Revolution. Students studied in primary schools for five years, beginning the first grade at about age seven. Then they spent three years, designated the guidance cycle, in a middle school. In this cycle, the future training of students was determined by their aptitude as demonstrated on examinations.