By Gary Eason
Education editor, BBC News website
The government's performance tables have again been criticised, as the results for every secondary school and college in England are published.
Top head Michelle Magrs said the tables could be damaging
Education union leaders said the tables - changed again this year - were more complicated but just as misleading.
Even successful head teachers cast doubt on their usefulness to parents.
Schools Minister Jacqui Smith said they showed standards were rising - but the government was not complacent and controversial new reforms were needed.
The White Paper proposals for England's schools - opposed by many Labour MPs - would build on that success, Ms Smith said.
She added: "For the first time ever we are also publishing information on how schools have performed against a new tougher measure showing achievement in English and maths - the basis of a good education."
TABLES FACTS AND FIGURES
4,108 schools and colleges
At end of Key Stage 4:
Level 2 exams (GCSE) taken by 633,464 pupils
57.1% got at least five good grades
44.9% including English and maths
average 277.6 points per student
Such results were published last October by the BBC, which obtained the 2004 figures under the Freedom of Information Act.
They showed many schools were not as successful as they appeared, once those core subjects were taken into account.
But the 2005 results now issued officially do not feature in news organisations' "league tables" because ministers refused to make them available to journalists.
The Department for Education and Skills said doing so would "prejudice the effective conduct of public affairs" by undermining its tables.
Nationally, the proportion of the 633,464 pupils whose qualifications included good English and maths grades at the end of Key Stage 4 was 44.9% - and 15.6% in city academies.
The government's flagship city academy programme is coming under fire because about half of the 27 schools are near the bottom of the new tables.
Steve Sinnott, general secretary of the National Union of Teachers, said: "Millions of pounds of taxpayers' money have been thrown at academies by the government.
"It makes constant claims of a success story which cannot be sustained by the evidence."
But schools which are selected to become academies are typically among the worst-performing in the country and the government argues that it will take time to turn their fortunes around.
Ms Smith said academies were among the fastest-improving schools in the country.
But a potential confusion in the tables is there are two sets of GCSE-level results.
One relates to the end of Key Stage 4, now the government's preferred measure. The other shows attainment by 15-year-olds, which is what it has counted until now.
On that old measure the national English and maths score was 44.3%.
The headline figures for the equivalent of any five good grades at GCSE level were 57.1% and 56.3% on the two ways of counting it - an even bigger jump than shown in the provisional figures last October.
The general secretary of the Association of Teachers and Lecturers, Mary Bousted, said: "The school league tables have become far more complicated in the government's attempt to make them less misleading."
She said: "What parents really want is a school where their child will be safe, happy and well-educated, but league tables encourage them to rely on dubious performance statistics."
Her counterpart at the Association of School and College Leaders, John Dunford, said the results were "a real success for the system".
But league tables offered "a misleadingly simplistic view" of performance.
His remarks were echoed by the head of one of the most successful schools, Michelle Magrs.
Her technology college for girls, Selly Park in Birmingham, was one of the schools whose pupils make the most progress.
"You can use statistics to show anything," Ms Magrs said.
"Tables can be damaging to some schools who are trying their utmost to support their pupils."
Liberal Democrat education spokesman Edward Davey said the reliability of league tables was in question.
"Any conclusions ministers claim to draw from them are bordering on meaningless."
He added: "In their current form they produce more misinformation than useful data for parents."
But Ms Smith said tables were "a non-negotiable part of school reform".
"Parents have a right to see this information."
It should be considered alongside other important sources such as Ofsted reports, school profiles and school prospectuses.
The top school at GCSE level is - as last year - Thomas Telford City Technology College in Telford, Shropshire.
It was one of 215 schools were everyone achieved at least five good grades but had the highest average points score: 771.7.
At A-level the best performer, also for the second year, is Colyton Grammar in Devon where students averaged 529.1 points - more than four A grades.
The education authority with the best performing schools at GCSE level is Trafford. Bristol did worst.