Teacher talking time
Teacher talking time or (TTT) refers to the amount of time the teacher spends talking in class. Teachers are frequently advised to keep this time to a minimum in order to allow for more student talking time.
Simple maths will show why this is important. Let us imagine that a lesson lasts an hour, that half of that time has been set aside for talking and there are six students in the class. In this rather ideal situation, if the teacher speaks for "only" half of the time then there will be fifteen minutes for the rest of the students. Assuming that the time is divided equally amongst the students, that is, none of them are hogging the conversation, they will speak for little over two minutes each. Even if the teacher did not say a single word, then student talking time would still only be five minutes each.