Headteachers at Camborne, Pool and Redruth secondary schools have expressed concern over the value of the GCSE league tables following their release last week.

Despite most heads being pleased with the results overall, the way in which the figures were correlated concerned some, while others felt the tables were of limited use to parents choosing a school for their child.

Camborne headteacher Ian Kenworthy said: "At the end of the day, Camborne is a high performing school and achieves very good results at key stages three, four and five. In comparison with similar schools we're doing extremely well. We're very pleased with our performance, we've got some excellent results and, as with Pool and Redruth, the students achieve their potential.

However he added: "League tables are league tables and they are not a measure of the quality of teaching and learning that takes place or how successful or unsuccessful the school is. I think most headteachers would agree that in making a choice of secondary school, parents are too astute to take too much notice of league tables. There are many more important factors that determine parental choice."

Zelma Hill, head of Pool School, expressed similar sentiments: "It's very difficult for even a professional, let alone a lay person, to understand these tables," she said.

"In terms of value added for Pool, our key stage two to three results put us in the top 40 per cent of schools, and our key stage four results put us in the "average" band. But even saying that, the data is flawed.

"I don't know how valid that information is. I'm not nave, I know parents have to judge schools, they have to make decisions, but they have to make that decision on the basis of lots of things. They have to visit the school and decide if it is the right school for their child.

"Of course parents are interested in them, but I know enough to be wary that there are issues with the results."

Redruth School's headteacher John Shears said: "I don't know that they're a good or fair indicator, because they're so simplistic really. They only show a little part of school life. I don't know how long parents spend working with them.

"Most parents do a lot more work than reading a line that appears in January. I think they're of limited value, not showing the whole picture. We were reasonably pleased with our performance last year. Every year there is a different cohort with different strengths and abilities and the main thing is they did themselves justice."

Head of education at Cornwall county council, Doris Ansari, said the county as a whole had done "extremely well," compared to the rest of the country.

"As far as pupils achieving five or more A to C grades are concerned, we've been increasing year on year since 2000," she said.

"The national average is 52.9 per cent and Cornwall's is 54.4 per cent, so we're doing better than the national average.

However, she echoed headteachers' concerns over the value of the tables saying: "They are only part of a measurement of a school, and schools deliver much more than just testing at certain stages of a child's career.

"Education is about learning to read, write and do mathematics, but it's also about education in its entirety. If you have a good experience at school that makes an enormous difference to your life and I think the league tables don't always reflect the good work that goes on in our schools."