Islamization of textbooks. Schools were then segregated according to the sex of students. Observation of Islamic Law in schools became mandatory and religious ceremonies were maintained. By the 1990s, more significant changes arose. The annual academic system switched to a system based on credits. For example, if a student were to fail a class, rather than repeating the whole year they would simply retake the credits. The mandatory duration of high school was shortened from four years to three, however the fourth year was still available as an option to bridge the gap between high school and university. Also, many technical and vocational programs were added to help train students for the workforce, which proved to be popular with students. Modern education The first Western-style public schools were established by Haji-Mirza Hassan Roshdieh. Amir Kabir (the Grand Minister) helped the first modern Iranian college establish in the mid-nineteenth century, and the first Iranian University modeled after European Universities established during the first Pahlavi period. There are both free public schools and private schools in Iran at all levels, from elementary school through university. Education in Iran is highly centralized. The Ministry of Education is in charge of educational planning, financing, administration, curriculum, and textbook development. Teacher training, grading, and examinations are also the responsibility of the Ministry. At the university level, however, every student attending public schools is required to commit to serve the government for a number of years typically equivalent to those spent at the university, or pay it off for a very low price (typically a few hundred dollars) or completely free if one can prove inability to pay to the Islamic government (Post secondary and university). During the early 1970s, efforts were made to improve the educational system by updating school curriculation, introducing modern textbooks, and training more efficient teachers. The 1979 revolution continued the country's emphasis on education with the new government putting its own stamp on the process. The most important change was the Islamization of the education system. All students were segregated by sex. In 1980, the Cultural Revolution Committee was formed to oversee the institution of Islamic values in education. An arm of the committee, the Center for Textbooks (composed mainly of clerics), produced 3,000 new college-level textbooks reflecting Islamic views by 1983. Teaching materials based on Islam were introduced into the primary grades within six months of the revolution. Grades Budget