 As a foreign national, he spent at least two years in an internment camp in Canada before returning to England where he took up a post teaching science at the Dragon School in Oxford.While there, he developed what was really an early form of CBT without computers, using boxes of numbered cards, containing questions, answers, tutorial material, or descriptions of experiments, on a variety of different subjects.Sommerhoff later became a Research Fellow in Systems Theory at University College, London.