It's not just Mrs Merton who enjoys a heated debate. Class discussions can be a useful learning tool for any age group, but are perhaps particularly suitable for the more relaxed and informal style of teaching that is often appropriate for use with sixth formers.
But there are always risks. With younger children, the biggest challenge is to keep order and make sure the discussion doesn't degenerate into a free-for-all. With sixth formers, the principle hazard is slightly different: that one student will take it too far and assume more familiarity than you bargained for.
This is a common problem, especially with younger teachers, says Jon Berry, senior lecturer in education at the University of Hertfordshire. He believes it often originates in presuming sixth formers are more mature than they are.
"It is always worth bearing in mind that a few months ago they were Year 11s," he says. "It is strange that we expect them to have changed from schoolchildren to young adults in the space of a few weeks."
He warns that there are pitfalls in getting too friendly and cosy with students. A degree of familiarity implies a certain level of trust, but sixth formers may not have learnt to cope with the boundaries of adult relationships. But if you have already got to the stage where a sixth former is abusing your trust, you need to deal with them exactly as you would with a younger child.
"Take them to one side and explain that their behaviour is unacceptable," he says. Pointing out where they have overstepped the mark and making it clear that you are not happy about them doing so is often the most effective tactic.
This could involve a clear and non-judgmental conversation, says Paul Dix, managing director of behaviour management specialists Pivotal Education.
"You must gently redraw the lines," he says. "Emphasise your commitment to building mutual trust and respect while being honest about the boundaries to your relationship."
Sixth formers aren't friends
There is a difference between being friendly with your sixth formers and being their friend. It is possible to maintain a friendly relationship with sixth form classes, but only if this does not distract them from the object of the lesson and cause their achievement to suffer.
Your conversation with the errant student could also cover the need to create different working atmospheres in the group. It may be enough to discuss the behaviour you want to see and give a clear rationale for it, or you may want to turn this into an agreement with the student, whereby you identify the behaviour you want to see and hold a follow-up meeting to review progress.
A more adventurous tactic, Mr Dix says, would be to invite the student to lead a lesson. If they get an understanding of your needs as a teacher, they may well be more receptive to what you're trying to do. But, whatever your approach, you should be prepared to deal with some resentment, and perhaps some embarrassment.
"Making the boundaries really clear and adjusting expectations may cause some strain in the relationship temporarily, but in the long term a more productive partnership will emerge that allows you to find the right balance," says Mr Dix.
You should bear in mind, however, that even though they are in the sixth form, they are still subject to the same rules of behaviour as younger children. If your attempts at redrawing the boundaries fail, then you should treat them as you would any other erring pupil.
"Loath as you may be to use the school's disciplinary procedures with a sixth former, it is open to you to do so," says Mr Berry.
Undoubtedly this would cause some short-term awkwardness, so the safer option is to stop it ever getting to this stage
Keeping authority in the classroom
. Take the student aside and tell them their behaviour is unacceptable.
. Explain why you want to use both formal and informal methods in your classroom.
. Consider using school disciplinary procedures as a last resort.