barrows joined the usc faculty in 1960, advancing to the rank of professor of neurology. in 1971, he joined the recently founded faculty of medicine at mcmaster university in hamilton ontario. it was at mcmaster where he developed the pbl curriculum. a decade later, he was recruited to serve as the associate dean for educational affairs at southern illinois university (siu) school of medicine in springfield, illinois. at siu he was instrumental in establishing a pbl track modeled after the problem-based curriculum at mcmaster. under his direction, siu became a center for the development of pbl teaching materials and faculty training. he played an instrumental role in creating the journal "teaching and learning in medicine" and served as an associate editor for many years. he also established the problem-based learning institute in conjunction with the local public school district to promote the use of pbl in secondary education. after his retirement in 1999, barrows and his wife phyllis returned to hamilton, ontario.