STT stands for student talking time. It is the percentage of the time the students speak. The CELTA way of teaching demands less TTT (teacher talking time) and more STT. The following questions will help restrict TTT and ensure more STT:
Ø What percentage of the time does the teacher/do the students speak?
Ø Does the teacher give a 'running commentary' of the lesson ('Now I'm going to do X' or 'I was going to do Y but I forggot to bring) or 'echo' the students' responses?
Ø Are the students given enough opportunity to speak to each other in a meaningful way during the leasson?