One example, favoured by Positivists is the Flanders System of Interaction Analysis Categories (FIAC). This is used to measure pupil and pupil-teacher interaction quantitatively. Observed using a standard chart to record interactions at 3 second intervals, placing each interaction into 1 of 10 categories. It found that in American classrooms 68% of time was teacher talking, 20% pupil talk, and 12% silence or confusion. Relatively simple method makes it quicker, cheaper and require less training.