Schools will be judged on the quality of their teachers - rather than solely on their pupils' results - under plans to overhaul the interpretation of GCSE results in Wales, TES Cymru has learnt.
The Assembly government is procuring a contract with an organisation that will score schools on the number of pupils who do better than expected, not the number of top grades pupils achieve. It follows a successful trial when all schools in Wales were sent data revealing how far they had exceeded or fallen short of expectations compared with similar schools.
Under the new contract, all schools will be sent two sets of scores next year. In the first simple value-added measure, pupils' grades will be compared with their teacher assessment scores from previous years. The second set will be contextual value-added (CVA) scores, which take pupil poverty into account based on ethnicity and free school meal entitlement.
These new figures will not mean more work for staff, but heads will be expected to place more emphasis on them in self-assessments.
The scoring system should also make results more accessible to parents. Its supporters say that the increased public awareness it would bring stop schools with good teachers being labelled as bad places to send children.
Publishing the scores in the press could also reveal the hidden "success stories" of secondaries that are punching above their weight, while uncovering the truth about other schools where relatively good results give a false impression of their real teaching standards.
According to last year's value-added scores for Welsh local authorities, 64 per cent of pupils achieved five top-grade GCSEs in Neath Port Talbot compared with the predicted 54 per cent. By contrast, 9 per cent fewer than expected gained five top-grade GCSEs in Denbighshire - which is the lowest value-added score in Wales (see panel, below).
Dr Philip Dixon, director of teachers' union ATL Cymru, said value-added scores were a better indication of teaching standards than pupils' raw results.
"I think focusing on value-added scores will give more nuanced and sensitive data than those we have now," he said. "On their own, exam passes at GCSE and A-level are a rather crude mechanism, which unsurprisingly shows that children in middle-class areas do very well."
Dr Dixon said the data would flag up the real "success stories".
"There might also be one or two schools that look very good but aren't doing enough to push the best students," Dr Dixon said.
"But a number of schools in deprived areas will come out very well in terms of improving pupils' life chances. It would be a great tribute to the staff there."
The move towards contextual value-added results comes months after the government unveiled plans to make public teacher assessments for key stages 1-3. In new reports, parents would be shown a school's progress compared with local authority and Wales averages.
David Reynolds, professor of education at Plymouth University, said: "What this new value-added data does is allow you to examine the variations within a school, to go into different departments and see which ones are really good."
A government spokesperson said value-added scores would form part of a school's "core data", which would help self-evaluation. He said it would be good practice for schools to provide these new scores to parents if asked.
WHO ADDS VALUE?
Top five authorities in 2008
Neath Port Talbot, Vale of Glamorgan, Carmarthenshire, Swansea and Conwy
Ceredigion, Blaenau Gwent, Monmouthshire, Flintshire and Denbighshire.