A study by Ruhl, Hughes and Schloss, lecturers were told to pause for two minutes on three occasions during each of five lecturers, each interval lasting for about 12-18 minutes. Students did not interact with the lecturers during this time and instead reworked notes or discussed with a partner. When each lecture finished students spent three minutes writing down everything they could remember from the lecture. After 12 weeks they were given a multiple choice test to measure long-term retention. At the same time, a control group were given the same lectures but without the two minute pause. The group of students who had been given a two minute pause did significantly better on the recall and comprehension tests by up to two grades higher!