"Coasting" schools, which rely on the ability of their pupils rather than good teaching to produce results, will be officially identified for the first time and labelled "under-achieving", Ofsted, the standards watchdog, said. Such schools often fail to stretch their brightest pupils.
Failing schools will continue to be designated as being "in special measures" and those at risk of failing as having "serious weaknesses".
Ofsted's critics say that, at present, too many inner-city schools fail the checks because of social disadvantage while under-performing schools in more affluent areas escape.
Peter Matthews, head of Ofsted's inspections quality division, said: "It is very likely that parents could be quite pleased with some of these under-achieving schools. Inspections can tell parents whether schools are really doing enough for their children."
Ofsted admits that inspectors may have failed to detect some "coasting" schools. Mike Tomlinson, Ofsted's director of inspection, said: "What we are trying to do is to make the identification of these schools more systematic so they can be forced to take action to improve."
The changes are part of new arrangements for "light touch" inspections, which will mean that schools that seem to be performing well will be visited only every six years instead of every four.
Ofsted has already identified those schools - about 20 per cent - which will have light touch checks. For a big secondary school that will mean a three-day inspection by five inspectors, about 15 inspector-days compared with about 60 for a full inspection. Some teachers will not be assessed.
To qualify for lighter inspections, schools will need a good previous inspection report, exam results that show a rising trend and results which compare well with schools of a similar type as well as the national average. Mr Tomlinson said that schools in all types of socio-economic circumstances would be included in the first 20 per cent.
Schools may still fail if inspectors find unforeseen weaknesses, and there could be a follow-up inspection within a year for those that do not live up to expectation.
For the first time, inspectors will collect evidence about pupil mobility, which teachers and academics say is an important cause of low exam results in some inner-city schools.
Mr Tomlinson acknowledged that the new framework reflected concerns about the need to take more account of the background of schools' pupils. But he said inspections would be as "hard-edged" as ever and there would be no acceptance of "the culture of excuses" condemned recently by the Prime Minister.Reuse content