Results of introducing cooperative working methods on a distance learning course in physics are reported. This has increased the throughput of students in the course as measured in the number of ECTS points generated by the students. There is no significant indication that students more experienced in academic studies manage to complete the course more often than those with less experience. In student groups where the cooperative concept was fully realized a larger gain of knowledge was achieved, as measured by the force concept inventory test. Hence, it is important for the tutor to monitor activities in the groups by follow-up questions during the course and to stress the importance of all students participating actively.