Education unions last night welcomed radical moves aimed at reducing the stress of school inspections on classroom staff.

Teachers will now grade the quality of their own work as part of a radical overhaul of the way school standards are measured.

Under the plans, performance will be monitored in five categories, compared with 14 reviewed under the old model. Teachers will get around a month to evaluate their own work. Inspectors will then analyse the results, working with schools to establish if their ratings are fair and just.

The Herald exclusively revealed in May that moves would be made to alter the inspection process. Details emerged yesterday at the annual conference of Her Majesty's Inspectorate of Education (HMIE).

The changes follow widespread criticism that the old culture of inspection was too adversarial, with disproportionate levels of stress. This pressure was widely speculated to have led to the suicide of Borders headteacher Irene Hogg as she waited for an HMIE report into her school.

Graham Donaldson, senior chief inspector of schools, said the new model would be "less intrusive and less stressful" for staff and would promote a more constructive dialogue between inspectors and teachers.

He said: "If we go into schools sometimes they can adopt an aggressive attitude. It can be very difficult. This is about both of us working together."

He said he was "very confident" that the new system would be as robust and added that safeguards were in place to make sure schools had not become "deluded" about their own standards.

Mr Donaldson played down the link between school inspections and the burden of stress it placed on teachers, however, adding: "I think (the issue of) stress in relation to inspections is interesting. The reality is that the stress comes from a school which is not well run, it comes from a school where teachers feel isolated."

He later declined to be drawn on the professional pressures reported to have led to the death of Mrs Hogg: "I know that the inspection of the school was conducted in a very professional manner. I think it is unhelpful for Mrs Hogg's memory to comment on speculation."

Self-evaluation of schools has been carried out in Scotland for 15 years as part of the overall inspection process, but will this term become the central plank on how standards are measured.

Fiona Hyslop, Education Secretary, said the new model was chiefly about raising standards in schools but would also help to lift some of the stress on teachers. "This is about improving the process and it should reduce any unnecessary stress," she said.

Ken Cunningham, general secretary of the Headteachers' Association of Scotland, said that the self-evaluation model was a welcome step.

He said: "The process has been far too heavily bureaucratic in the past and put an enormous stress and strain on schools."