The annual November publication of national exam results at the grey stone edifice on the south bank of the River Tyne does not bring a stampede of journalists to photograph clutches of pupils with straight As. Raw data shows it nearly 10 percentage points below the average Gateshead secondary in pupils gaining five or more GCSEs at grades A to C; the authority itself is 78th out of 109 councils.

But the unveiling of a plan for value-added tables by the School Curriculum and Assessment Authority will bring a smile to the face of deputy head David Telford-Reed. If anything, the idea is a little recherche: he has been producing his own value-added data since 1986. The range of the information available now extends to differences between individual pupils, departments, genders . . . and teachers. First years at Blaydon sit National Foundation for Educational Research tests for literacy, numeracy and reasoning. Assuming a score of five for an average pupil, on a scale of one to nine, Mr Telford-Reed calculates the likely GCSE results. Then by plotting a graph (NFER on one axis with the actual GCSE performance on the other) three bands can be created of those who have done as expected, worse, or better (the added value).

The happy result for the 1994 GCSE group: 43 per cent did better than predicted, 35 per cent as expected, while only three pupils ended up in the Cartesian wilderness of underachievement.

“It gives a broader picture of how the school is doing,” said Mr Telford-Reed, who is working with another school on computerising the system. “It is easy to administer, it seems to work and it gives information that can be given to governors and parents. We have generally been able to pick up stragglers and put in the support to help them do what they are supposed to do.”

Teachers are free to show charts drawn up after mock exams to underperforming pupils. Weaknesses and strengths can also be gauged among departments and teachers, the latter through a system devised by another school in the area which analyses how pupils perform in a particular class compared to their average in all subjects. “We can see if we are getting more bangs per buck from different parts of the schools. This can be used as a stimulus.”

Will it end with league tables of teachers pinned on the staffroom wall? No, although if it came to the number crunch such figures could be used for performance-related pay. As Mr Telford-Reed cheerfully admits, insensitive use of such statistics, if plotted on one side of a graph, would be mathematically linked to “the possibility of getting lynched” on the other.

“You can establish that Mr X can always do better. But it’s a very threatening method. We have variations but we haven’t had any horror stories and there has been no real hassle. The awareness of staff has improved.” If a teacher consistently underperformed, says the deputy head, “you would be irresponsible if you did nothing.”

The system was created while Mr Telford-Reed was on secondment to Newcastle University. It coincided with a closure threat - Gateshead wanted to turn the school into a tertiary college as part of a post-16 reorganisation. It took several years to escape that danger, during which numbers halved from 1, 100, with the loss of many middle-class children and a drop in exam results. The value-added data were vital in putting the case that the school was delivering for the pupils who remained.

Two other schools in the area now compile similar data. The one statistical cloud is the accuracy of the link between each NFER score and GCSE grades. Blaydon says it is a “valid measure”, but this has not been proved beyond doubt. Using national curriculum key stage 2 test results would be a more direct link, but because most pupils end up in one or two levels, the measurement is too crude for comparison with GCSE results.

However it may be taken up nationally, Blaydon sees a need for the system to help the school survive. The noisy Edwardian corridors and classrooms are threatened again as the council is cutting surplus sixth-form places and the school wonders if it will be viable if it was forced to lose two senior years and become 11 to 16.

“We believe the value-added figures show we are doing a good job. You have to get over the prejudices that pupils bring to school, that it isn’t smart to be clever. Once you have cleared that hurdle, you can improve things dramatically. ”