Light-touch inspections mean far fewer schools are judged good or better, upsetting unions and heads, reports Jon Slater.
The number of schools judged to be good or better by Ofsted has dropped sharply because of the new, light-touch inspections.
Only slightly more than half of schools inspected last term were judged good or better, compared to almost 70 per cent last year.
The proportion of schools judged to be failing or causing concern has risen from 8 to 9 per cent, according to Ofsted's figures.
Headteachers' leaders said the changes were ridiculous and raised questions about the reliability of Ofsted's judgements.
The new framework for inspection, introduced in September, relies heavily on school self-evaluation and a new value-added measure of performance.
Schools are inspected once every three years instead of every five but inspections are shorter, with fewer lesson evaluations and a greater reliance on pupils' views.
Maurice Smith, chief inspector, said: "The new inspection arrangements have raised the bar - and rightly so - although without putting it out of reach.
"The performance of schools, and the public's expectations of them, have both risen. It is right that inspection should reflect that. Every school should serve its pupils well and should aim to serve them better."
Of 1,850 schools inspected in the spring term, 172 (9 per cent) were judged outstanding and 815 (44 per cent) good, while 688 (37 per cent) were deemed satisfactory and 175 (9 per cent) inadequate.
Since September, 3,984 schools have been inspected, of which 10 per cent were outstanding, 47 per cent good, 34 per cent satisfactory and 10 per cent inadequate.
Mr Smith said: "The really good news is that almost 60 per cent of the schools we have inspected have been good or better. We want their achievements to be recognised and celebrated."
Mick Brookes, general secretary of the National Association of Head Teachers, said schools judged to be outstanding under the old system were now often only satisfactory.
He said: "It is quite ridiculous. The whole idea that what was good is now average means you really have to question the authenticity of Ofsted's judgements."
Mr Smith, however, repeated his views, first revealed by The TES last month, that parents and pupils need to stop treating schools as "fun palaces".
He said parents needed to ensure children were "up and ready for school, awake and alert - not tired and lethargic from last night's television, computer or entertainment."