“Right Year 9, I’d like to introduce Mr Openshaw. He’s a visiting teacher and will be taking you for this lesson.”

Thirty faces swivel. Knowing glances are exchanged. The form jester’s eyes widen as he senses his prey - lesson five might not be so dull after all. The poor young man might as well have “STUDENT” tattooed across his forehead.

With an encouraging if sympathetic smile, the mentor is gone. The student is alone. He strides forward purposefully, clutching his lesson plan. The curtain has risen on his teaching practice.

Five minutes later, things are going well. A snappy introduction and the pupils are all heads down on their first task. No problem. What was all that sweating over planning in aid of last night? He is swept by delusions of competence.

And then comes the first snigger. Not a big one, but definitely a snigger. It fades back into silence and the class waits for a reaction. The peace is broken by a bag crashing from a desk. A snort from the jester sets the girls giggling.

“Get on with your work, please.”

The table in the corner quietens. Grinning heads look down once more. The only sound is the scratching of pencils and the distant hum of traffic.

All is well. The student pats himself on his back. An effective piece of discipline carried out.

An eraser gently sails across the room and lands in Jane’s lap. She yelps in surprise. Retaliation is immediate, and Jester and Jane are soon in heated dialogue, with the rest of the class looking on in excited anticipation. The student realises that he must act quickly to establish his authority.

He must be seen to be decisive. His mentor’s words “firm but fair” echo through his mind. “Calm and reasonable, never shout, never lose your temper, ”

he had read in a teaching book last night. “A quiet voice is often more effective than a loud one.” The book had been quite clear.

“Right you two, settle down, give the rubber back,” is said with calm reason and firm fairness - and, of course, spoken in the quiet voice of authority.

The class does not settle. Jester and Jane do not sit down. That is, until the timely return of the mentor. No quiet coolness here. No firm reasoning. An ear-piercing yell, a thunderous face and Year 9 sit in obedient silence.

So what is a poor student to make of all this? The books talk of being a model of restraint, but what is the point when you see that rolling out the heavy artillery gets instant results?

The unenviable task of budding teachers is to pick their way through their observations and advice, and reach their own conclusions on how to maintain control, and deal with the Jesters and Janes effectively.

Charley Openshaw is completing a PGCE course at Anglia Polytechnic University.

He graduated from Wimbledon School of Art in 1996 .