They are seldom disappointed, and neither are the staff. But the fundamental mistake they make time and time again is to ask the front row. I do it myself sometimes, but then I know them, I know who to avoid. With the precision of a laser-guided missile they unerringly pick from a sea of raised hands the one child you would never ask. OFSTED inspectors have this very same gift.

“Think of something you’ve read.” A simple request. Up go the hands. A blonde cherub in the front row replies: “My dress.” Well, you see she has got a red dress but the visitor just looks bemused. A nice young clergyman had the whole school listening intently when, by way of explaining something, he said: “Say you lived in the country. . .” The whole front row repeated back at him: “You lived in the country.” Total consternation.

Assembly visitors often forget how egocentric very young children can be. They are quiet, sitting up straight, and look as though they are hanging on every word. The visitor asks a simple question and members of the front row strain to raise their hand the highest and the straightest. Then the answer: “I can wipe my bottom all by myself.” Some visitors recover quickly to such an answer, others go into a state of shock and have to be rescued by a member of staff.

One of the most shameful moments came when we had had a wonderful assembly on asthma performed by a trio of young black actors. “Would you like to ask any questions?” one said. “Do you pick cotton?” came the swift reply. There was an uneasy silence as we all sat wondering where on Earth that had come from. Had she seen a film, an old photograph? Would they think we were a bunch of bigoted racists?” The actor quickly recovered his composure, said:

“Not recently,” and moved swiftly on. So if you happen to pass by our school and see a visitor stumbling out swearing never to return, don’t worry, it was only the front row. We’re a bit short of visitors at the moment, any offers Mr Blunkett?

Sue Walker is headteacher of Upland infant school, Bexleyheath, Kent