A demand that examination boards which make mistakes should compensate pupils and teachers was agreed unanimously by the North's largest teachers' union in Belfast recently.

The annual conference of the National Association of Schoolmasters Union of Women Teachers, which claims 9,000 members locally, deplored the poor standard of service provided by many examination boards. Delegates sharply criticised the Northern Ireland Council for the Curriculum Examinations and Assessment (CCEA) for a spate of errors in recent years.

Last month the council admitted losing 255 mathematics papers from 65 schools for the winter General Certificate in Secondary Education (GCSE) examinations. It also announced that it had given higher marks to more than 1,000 candidates following two errors in last June's advanced level chemistry examinations.

Belfast delegate June Harrison said it was time to make examination boards accountable for the anxiety they cause. "If they had to pay compensation there might be more checks." She said CCEA should be nationalised if it did not improve.

Larry Fitzsimons, honorary secretary of the union, said CCEA was not fit for its purpose and not properly managed. "It is time for an independent inquiry into its operation," he told the conference. This was supported by executive member, Marcus Duignan, who criticised CCEA's "favoured status" - in which it was protected by the Department of Education.

Earlier, a guest speaker, Dr Hugh Morrison, a statistician at Queen's University Graduate School of Education, claimed that the UK now has a more obsessive test culture than the United States. A key difference is that schools and teachers had no protection from technical fidelity standards which governed educational bodies elsewhere in the world.

This was now extremely important because of the high stakes involved. Under current proposals, school budgets will be affected by their performance and teachers' pay may be determined in part by their ability to meet targets and add value as measured by levels or grades.

Morrison sharply criticised the failure of CCEA and its British counterpart, the Qualifications and Curriculum Authority, to publish data to justify the technical fidelity of their tests.