Are working-class pupils being denied the chance to study traditional academic subjects by their schools' drive for success in GCSE league tables?
That is the question behind today's TES analysis of last summer's results from secondaries classed by the Government as among England's most improved in 2001-4.
Data provided by 88 of these 104 most improved schools reveal that in many of them very few pupils are achieving good passes in some academic subjects.
The schools appear to owe their positions in the rankings to having introduced general national vocational qualifications in courses such as ICT and science.
Because many of their pupils are doing well in GNVQs, their success rates in subjects such as languages, history, geography and academic science do not show up in government statistics, which focus on pupils achieving five or more grades A*-C GCSEs or their vocational equivalent. This is why the TES has investigated the schools' achievements in these subjects.
GNVQs count as four GCSEs and tend to have higher pass rates than academic subjects. Many of the schools on the most improved list are in inner-city areas with a less academic profile, so would be expected to have fewer children entered for traditional subjects.
But the figures are still striking. On average across the 104 most-improved schools, only 15 per cent of pupils achieved a C in a GCSE language or better.
At 12 schools, fewer than 20 per cent were even entered. Seven schools had not a single pupil taking history GCSE. At Waverley school, Birmingham, every pupil wanting to study science had to take a GNVQ.
These science courses are designed for pupils with a vocational bent, and are meant to offer youngsters the foundations for a career, for example, as a lab technician. They are not, however, widely seen as a foundation for A-level study.
Kamal Hanif, head of Waverley school, said: "I do not think it was ever really meant to be a foundation for A-level. It was about providing other routes into science. The key issue is that post-16colleges have not valued GNVQ science."
Mr Hanif said the school would now be reviewing its curriculum to offer academic as well as vocational science courses.
The school, where only one of 112 Year 12 pupils was entered for a European language GCSE this summer, has broken free of a federation led by Ninestiles college, which was previously praised by inspectors for improving results.
Tony Broady, head of Walker college, Newcastle, where all of the more able pupils took GNVQ science in 2005, agreed that it was not a good preparation for A-level. Top-set Year 10 pupils are now doing double GCSE instead.
Advocates of vocational options argue they broaden the curriculum. But some heads contend that offering vocational courses means provision in other areas must be cut in smaller schools.
John Reilly is head of Winchcombe school, a small all-ability comprehensive in Cheltenham, which was one of the 30 most improved schools last year despite not having introduced GNVQs. He said he had considered doing so, but baulked at the thought that this might mean more pupils opting away from subjects such as history, which would therefore have become unviable.
He said: "Some smaller schools which have extended their curriculum to offer GNVQs must have done so at the expense of other subjects."
At Parkside technology college, in Plymouth, none of its 52 Year 11 pupils took history this year. But Valerie Jones, the principal, said it was offered. Two Year 10 pupils are now embarking on history exams via an online learning course.
St Luke's Church of England secondary, a comprehensive in Portsmouth, did not enter any of its 109 pupils for double science or history last year, while only four took a European language (French), and 14 took geography.
The widespread use of GNVQ ICT in particular illustrates how many schools'
performance in the tables has been transformed by the "Thomas Telford effect".
Thomas Telford city technology college, in Shropshire, was the first comprehensive in England where all pupils achieved five or more A*-Cs, partly because they all took GNVQ ICT. It then marketed electronic teaching resources to schools anxious to offer the course in the hope that they too would rise up the tables.
Many schools defend offering more vocational options. They are not introduced to improve statistics, they argue, but to give pupils the chance to study courses which will motivate them. Several said giving pupils the chance to be successful in a GNVQ course improved their motivation in other subjects.
Paul Trickett, of Rhyddings business and enterprise school, near Accrington, Lancashire, which was joint fifth on the most-improved list, said: "GNVQ is valued by employers and colleges."
Mr Broady said: "I do not take the view that because you have introduced courses pupils can achieve in, that it's something to be ashamed of."