During the first five years of his time as director-general of the IBO, Peterson continued to live and work in Oxford, despite the fact that the IBO offices were located in Geneva, Switzerland. He remained in his job at Oxford University, retaining the directorial job with the IBO as a part-time work. In 1973, he retired from his Oxford post and took up a part-time teaching job at the Hammersmith and West London College of Further Education, teaching Theory of Knowledge and managing his IBO directorate from London.