What should you look for in a school?

Ethos is a vital part of any education – and it's something you need to check out in person

Looking out over the grim industrial slag heaps of St Custard's, Nigel Molesworth, the hero of Geoffrey Willians' Down with Skool!, recalls a prospectus boasting of its beautiful setting.

To make sure your child does not end up terrorised, as in the book, it pays to learn as much as possible about the school. And to uncover that most ephemeral of educational frameworks, a school's ethos, you need to do the leg work and have a poke around.

An "ethos" may sound like the kind of waffle that league-table losers use to suggest that they are offering something better than top results and Oxbridge places, but even top scorers take it seriously and say it's something you have to check out in person.

"There's no substitute for a personal visit," says Dr Martin Stephen, High Master at St Paul's Boys' School in London. "Schools acquire reputations that last years and years, but bear absolutely no resemblance to the school itself."

Open days are much the same at most schools. Parents are taken around, work is exhibited or classes eavesdropped on, and parents are given the chance to talk to pupils. What should they be looking for?

Many schools merrily wheel out historical relics and reel out impressive lists of alumni (sometimes, ironically, people who hated the place when there). Don't be bamboozled. "The history is vaguely interesting, but hardly relevant," says Stephen.

Instead, he says, parents should be looking for the support and encouragement that the pupils are given. Most parents will be more interested in what happens when things go wrong than when all is well.

And leave your preconceptions at the door. "Loads of parents expect to see half the class inventing cold fusion with a paperclip and a marble while the other half tears their hair out because they can't keep up," he says. "In fact, we encourage pupils to do what they enjoy doing and do it well."

If even St Paul's struggles with parents' misperceptions, what hope is there for less famous schools? Faith schools, in particular, can find it hard to reach out beyond their own community, often because parents simply do not consider them an option. Most people's knowledge of Quakers, for example, begins and ends with an image of Puritan austerity on the front of a cereal box. But Britain's seven Quaker schools are far from austere.

"There's a friendliness and an informality that you don't normally expect to find in independent schools," says Jane Peake, the development director at Bootham School, a co-educational school in York, teaching 11-year-olds and up, which has an open day this Saturday.

"The relationship between pupils, and between pupils and staff, is really something we're very proud of," Peake says. "That feeling of cooperation is something that you have to come and see for yourself."

The school teaches on Saturday mornings, and lessons go on as usual during the open day. Peake believes this is an advantage. "You can be an observer. You can just sit back and watch it all going on around you."

Some schools really are too puritan for open days. "It's very much an occasion put on to put the school in the best possible light," says Nigel Home, headmaster at Bendarroch School in East Devon, a co-educational school for four- to 13-year-olds. Home shows parents around individually.

Bendarroch is one of a few UK schools that offer a radical alternative to traditional schooling, what Home calls a "distinct ethos". But that does not mean poor grades: Home says that over 6 per cent of pupils go on to get Oxbridge places.

"The most useful question a parent can ask is not what good can the school do my child, but what harm?", Home says. At Bendarroch, he argues, that will be very little. It is a bleak but useful way of seeing things. Will your choice of school open up opportunities or close them down? Will it encourage your children to learn? You need to see for yourself to find out.