The received wisdom that tells a young man to look at his intended's mother, to see how his beloved will develop in the future, can perhaps be paralleled in schools: doing a spot of shrewd assessment on them by looking at their former pupils. Certainly not infallible, but illuminating and fun.

As you read on though, don't jump to hasty - and erroneous - conclusions.

Bear in mind, that it's still far too soon for previously single-sex schools which have become co-educational in recent years, to see the gender once precluded from their ranks, feature in their halls of fame.

Glenalmond College in Perthshire, has a fine diverse cast of OGs, as former pupils are known. They include Adair Turner, director-general of the Confederation of British Industry; Lord Kingarth, Supreme Court Judge, and Lord Wilson of Tillyorn, chairman of Scottish Hydro-Electric, Chancellor of Aberdeen University, and a former Governor of Hong Kong.

Representing the media, are former ITV presenter Sandy Gall, and Alan Massie, both journalists and authors. The world of politics is reflected in former Scottish Office Minister of State, Lord Russell Sanderson, and flying the flag for the Arts - and indeed Scotland - across the Atlantic, is the celebrated civic sculptor, George Rickey.

Women increasingly make their mark in society, but high fliers are not exclusively confined to this century. St Leonard's, co-ed from September 1999, schooled for example, the first female First at Cambridge, in 1887.

Moving to more current times, Anji Hunter, special assistant to the Prime Minister, was at St Leonard's, and so too, was Rosemary Eliot, principal flautist with the BBC Scottish Symphony Orchestra.

The first woman to become the Queen's Chaplain, the Reverend Mary Levison attended the school, while in the world of high glamour, a far cry from her bracing, rosy-cheeked schooldays at St Andrews, Stella Tennant was the Face of Chanel, 1996.

Perthshire's Strathallan School counts amid its former pupils, Professor John Shaw, deputy governor of the Bank of Scotland; and Ian Jones, founder of Quayle Munro, the Edinburgh merchant bank, previously associated with Ivory & Sime and the British Linen Bank.

Famous sporting Strathallians include golfer Colin Montgomerie, and National Hunt jockey, Peter Niven, who according to Debrett's, has ridden more than 100 winners per season since 1991.

In the media, Tim Orchard has also distinguished himself. Starting out as a reporter, he worked on two Aberdeen newspapers, joining the BBC newsroom in Glasgow in 1974, then moving south in 1982. He is now controller of TV News Channels for the BBC.

Although he sees ''radical change'' in the development of the school today, compared with 30 years ago, Tim Orchard says: ''I get the impression that the way it conducts itself is exactly the same. It's very impressive.''

Among his perceived advantages in his Strathallan education are: ''Confidence to come out of your shell, there was an element of sink or swim 30 years ago, and encouragement to focus on that which you wanted to, it gave great opportunities.

''One of the things I did in my last two years was run an unofficial school magazine, Wing Forward. It wasn't underground, but it wasn't the annual Strathallian, and it kindled my interest in journalism.''

Some of the Labour Party's current leading lights were educated in the Scottish independent system. Prime Minister Tony Blair, for instance, attended Edinburgh's Fettes College, while Donald Dewar, the Scottish Secretary, is a former pupil of Glasgow Academy, and Alistair Darling, Social

Security Secretary, is a Lorettonian.

Glasgow Academy was the scholastic place of learning for Sir Iain Vallance, a former head boy, who has gone on to become chairman of BT, while another high profile FP, this time in the media, was Jeremy Isaacs, former Controller of Channel 4.

Wellington School at Ayr, formerly for girls but now co-educational, lists journalist and broadcaster Kirsty Wark and top model Kirsty Hume, as two of its best-known pupils.

Craigholme School, in Glasgow, still assuredly single sex, lists among its high flying former pupils, Lesley Bale, managing director of Aberdeen Airport, and Craigholme deputy head's daughter, Lindsey McCallum who, after gaining a first in European Law is now, at 30, a senior civil servant at the European Commission in Brussels.

Gordonstoun has grown famous as a school favoured by the royal family. Prince Philip, his three sons and two of his grandchildren, Peter and Zara Phillips, have all received their main schooling in the Morayshire countryside.