In headteacher folklore, a good assembly consists of a hymn, a prayer and a bollocking - a little simplistic perhaps, but like most chestnuts, it is sound at heart.

The hymn and the prayer pay homage to the law, respect the traditions of the profession and, if the essential belief is there, they permit of genuine religious witness.

Then comes a palpable divide, signalled by a clearing of the throat, a change of stance and posture, and a suitable exhortation such as, “Right! Sit up now! Pay attention!” After a little rustling - clearly showing that the pupils are also shifting gear - the hymn-writer’s message of love (“God who put the stars in space, Who made the world we share...”) is followed by the austere strictures of authority.

“Yesterday the dinner ladies came to see me, and I have to say that I did not like what I heard. Certain children - and they know who they are - are conducting themselves in a way that I do not expect of pupils of this school...”

Properly delivered, such a message makes everyone -including the teachers - feel guilty. “Was it me? Perhaps I really did do that thing with the custard? But surely I would remember?” Most apocalyptic of such utterances, of course, have to do with the toilets. The phantom toilet abuser is the bane of any primary head’s life, provoking blood curdling orations from the front of the assembly hall, their effect considerably enhanced by the impossibility of declaring in public the exact nature of the offence.

There are times, of course, when such assemblies are inevitable - an admonition needs to be given when the community is gathered together. In the Seventies, for example, every Birmingham head was required by the council to warn children not to drink the water in the canals (one head of my acquaintance would never issue this warning, believing that his omission was actually furthering the evolutionary process).

The danger, though, is that the head finds it too easy to do - no primary school can fail to generate at least one complaint a day. Running in the corridor, splashing water from the drinking fountain, bringing in games that involve the firing of blazing arrows on the playground, provoking the neighbours’ dogs, swinging on the gate, poking things down the drains, climbing on the roof, writing on the walls - finding this sort of assembly material calls for no effort at all.

The wise head, though, knows the rule, which is to give at least three (and preferably five) lots of praise for every telling off. Assembly, after all - and this is too readily forgotten by those who want it abolished with the daily act of collective worship - is when the head sets the philosophical agenda for the school.

When the head addresses the pupils he or she is, in effect, saying to the rest of the staff, “This is the tone of voice which we should be using to our pupils; this is the kind of thing we should be saying to them; these are the values we must uphold; these are the happenings, the people, the events, which we should present as significant. Take heed, and do thou likewise.”

If this is well done, then the change of gear between “the religious bit” and “the other bit” may be seamless or non-existent.

The school’s values will emerge from the moral or religious message. The significant school events will be made to lie alongside the happenings in the assembly story. The story itself will speak directly to the hopes and fears of the children. Properly done, the assembly becomes something that children and staff can enjoy and appreciate as a real family gathering.

Done without enthusiasm, though, it becomes a chore; children switch off and play with their Velcro shoe fastenings, or braid each other’s hair.

Every head, to my mind, should take on board the lesson of the teacher I know who provides signed support for hearing-impaired children in mainstream. If the assembly is boring, she simply holds her own signed assembly simultaneously with, but entirely different from, the “official” one. Nobody but her and her pupils know that this happens. It is their little secret, and a very happy one it is too.

Gerald Haigh is editor and chief author of Primary Assembly File, from PfP, 61 Grays Inn Road, London WCX 8TL