Six secondaries in the top 10 most improved GCSE results list told The TES that the rise would have been significantly lower if they had not introduced general national vocational qualifications. Croxteth community comprehensive, ranked number eight, said its results would not have risen this year if it had not started putting all of its pupils through a computerised GNVQ course.
A full intermediate GNVQ pass counts as four A* to C GCSEs.
However, most of the top schools made impressive improvements even if vocational results were excluded. Many heads also oppose omitting vocational results from tables as they could lead schools to over-emphasise traditional exams.
The findings will increase the controversy surrounding the use of vocational courses. Professor Alan Smithers, of Liverpool university, said:
"Parents may well be misled by these tables." Schools were being judged on the basis of two qualifications which were not equivalent, he said.
Last year, The TES revealed how Thomas Telford school, in Telford, Shropshire, made pound;7 million in two years from selling its online GNVQ courses to schools keen to improve their league table ranking. The "most improved" list ranks schools by the rise in the proportion of pupils getting five Cs or better since 2000, at GCSE or the vocational equivalent.
Croxteth school in Liverpool came eighth after this figure rose from 11 per cent in 2000, when the school was in special measures, to 47 per cent last year. In 2002, the figure was 20 per cent. Richard Baker, headteacher, said that this year for the first time, all its students took full intermediate GNVQ courses in information technology, worth four GCSEs.
He said: "Without the GNVQ results, we would have achieved about 20 per cent A* to C again in 2003. Quite simply, we had to improve our results or they would have closed us down."
All Saints Catholic school and technology college, in Dagenham, is ranked second after the GCSE score climbed from 45 to 89 per cent last year. But Desmond Smith, headteacher, said the rise would have been 20 points lower without GNVQ results. The school started running GNVQ ICT two years ago, and last year all pupils took them.
Mr Smith admitted that the use of GNVQs could give an "artificial boost" to scores, but defended their use. The school served a tough area and was surrounded by grammar schools. He said: "If you're running a school like ours, you have got to look for every edge you can get. I'm proud of what we have achieved."
Four other schools in the top 10, Brownhills high in Stoke-on- Trent, Kingsmeadow school in Gateshead, Waverley school, in Birmingham and top-ranked Sir John Cass school in Stepney, east London, said the GNVQ had significantly improved results.
But Haydn Evans, head of Sir John Cass, said: "It would be unfair on students to say the rise in the results was just because of them taking GNVQ." Four schools said GNVQs had not played a major part.
Jeremy Waxman, head of Halifax high, the 11th most improved school, said ranking schools purely on GCSE results would encourage heads to push all pupils onto GCSE courses, whether this was right for them or not.
The Qualifications and Curriculum Authority recently announced that GNVQs are to be phased out by 2007. However, Sir Cyril Taylor, chairman of the Specialist Schools Trust, has written to Charles Clarke, the Education Secretary, saying such a move is "outrageous" and "baffling".
He said that scrapping the qualification would send the wrong message to young people. Universities and employers said GNVQs were more valuable than double science GCSE. Sir Cyril said the decision should await the outcome of a review of secondary qualifications by Mike Tomlinson, former chief inspector of schools.
TOPSTATE SCHOOLS AT GCSE raw results 2003
TYPE OF SCHOOL % 5 A*-C GCSEs or equiv
Thomas Telford sch, Telford, Shropshire COMP MIXED 100%
Brooke Weston CTC, Corby, Northants COMP MIXED 99%
King David high sch, Manchester COMP MIXED 98%
Coopers' Co sch, Upminster, Essex COMP MIXED 98%
Watford girls grammar, Watford, Herts COMP GIRLS 97%
The King's sch, Peterborough COMP MIXED 97%
Wymondham college, Norfolk COMP MIXED 96%
London Oratory sch , London COMP BOYS 96%
St Thomas More RC, Tyne amp; Wear COMP MIXED 96%
Old Swinford Hospital, W Midlands COMP BOYS 96%
TOP STATE SCHOOLS AT A-LEVEL raw results 2003
Type of school Sixth- A-level Avg point Avg point form VCE score per score
per nos entrants student exam
Dame Alice Owen's sch, Potters Bar, Herts COMP MIXED 363 169 362.8 102.0
Watford boys grammar, Watford, Herts COMP BOYS 329 158 366.6 101.7
Watford girls grammar, Watford, Herts COMP GIRLS 324 159 358.2 100.8
Hasmonean high sch, London COMP MIXED 253 125 325.0 99.6
Lady Margaret sch, London COMP GIRLS 120 63 329.4 99.0
Bishop's Hatfield girls' sch, Hatfield, Herts COMP GIRLS 109 52 349.4 94.4
The King David high sch, Manchester COMP MIXED 149 68 297.1 94.0
Farmor's sch, Fairford, Gloucs COMP MIXED 153 71 303.1 93.7
Durham Johnston sch, County Durham COMP MIXED 296 156 320.3 92.9
St Mary's RC high, Chesterfield, Derbys COMP MIXED 255 130 331.6 92.8