Christine Gilbert says the focus is on getter a better deal for children
Education inspectors are bringing in tougher standards for England's schools which will require higher results for them to be rated good or outstanding.
From September, schools that succeed will probably face an Ofsted inspection every five years instead of three - unless parents demand an earlier one.
There will be a greater focus on those judged satisfactory or inadequate.
Teachers' leaders said a new emphasis on raw exam results would make things harder for schools in deprived areas.
Ofsted chief inspector Christine Gilbert said: "We are introducing a tougher test on attainment."
She said pupils' progress would still be paramount but the exam results they obtained would be taken into account more than in the past.
Pupils' outcomes: including attainment, behaviour and wellbeing
Provision: teaching quality, curriculum, care
Leadership and management
But the general secretary of the Association of School and College Leaders, John Dunford, said there was "considerable anxiety" among members about the new inspection framework.
He said: "I am extremely concerned that Ofsted is again raising the bar and making it harder to get good and outstanding grades.
"It's like telling athletes running a four-minute mile that they need to do a mile and a quarter in the same time."
He said: "The increased emphasis on raw results will make it more difficult for schools in challenging circumstances.
"Inspection has always been disproportionately stacked against these schools and this will make their tough job even harder."
It emerged last year that among the schools on a "hit list" of those where under 30% of pupils were getting good GCSE grades, including English and maths, were a number that had been rated "outstanding".
The leader of the National Union of Teachers, Christine Blower, said: "Many in the profession will suspect that the government has pressured Ofsted into abandoning the principle of taking into account the profile of the school community when making its final judgement, to support its stance of being tough on failing schools.
"This will destroy Ofsted's reputation for independence and reporting 'without fear or favour'."
But the chief inspector is making no apology.
"Our focus is on getting a better deal for children and young people," Ms Gilbert said.
Addressing one of the key criticisms of the present inspections, inspectors will spend more time actually observing lessons.
Ofsted said the new approach had been piloted for more than a year and took account of feedback from parents, schools, governors, inspectors and local authorities.
Most schools will have just one or two days' notice of an inspection visit.
Ofsted had proposed having "no notice" inspections, but it says some parents had complained this might mean they would lose the ability to give their views to the inspection team.
It said there might still be snap visits however if particular concerns had been raised, for example over children's welfare.
And schools that are already in Special Measures - deemed to be failing - and those with a Notice to Improve can expect to be visited at any moment.
The same approach will also be taken with about 40% of "satisfactory" schools.
Normally the better performing schools can expect to be seen once every five years, although Ofsted will use annual risk assessments to decide which ones to visit.
Ms Gilbert said: "This new framework represents an important shift in the way we inspect schools.
"We will double the amount of time we spend in classrooms observing teaching. We will engage staff in discussion about ways of improving.
"With greater emphasis too on the views of parents and pupils, we will ensure that these important voices are heard in inspection."
Part of her plan is to have annual surveys of parental opinion about their children's schools, starting from next year.