The early co-op program was not required; students could enter as traditional students or cooperative education students. By the 1935 academic year, nearly 80% of the student body had chosen the cooperative program. Students initially studied for eight-week-long terms alternating with eight-week-long work experiences. Male students generally took apprenticeships with craftsmen or jobs in factories; female students often served as nursing or teaching assistants. In 1921, when the program was inaugurated, fewer than 1% of available co-op jobs were outside of Ohio, but that grew to about 75% within 15 years.