School performance data explained
The BBC News website looks at key questions about the publication of school performance data in England.
What is school performance data?
School performance data is statistical information showing how well pupils in England have done in public examinations taken at key points in their educational journey.
Data is published for children's attainment in national curriculum tests, often known as Sats, which are sat at the end of primary school at age 10 or 11.
At secondary school level, data is published detailing pupils' performance in GCSEs (and equivalent exams) at age 16 and A-levels (and equivalents) at age 18.
What is considered to be acceptable performance at secondary level?
Secondary schools are considered to be "underperforming" if fewer than 40% of their pupils get five GCSEs at grade A*-C, including English and maths, and if the school has a below average score for pupils making the expected progress between Key Stage 2 (end of Year 6) and Key Stage 4 (end of Year 11) in English and maths.
Haven't there been changes to secondary school tables this year?
Yes. From this year, only a pupil's first attempt at a qualification is included for league tables, aiming to end the practice of schools repeatedly entering pupils for exams in order to could boost their ranking.
The list of qualifications included has also been restricted to those which the government says are of the highest, academic quality and the number of non-GCSEs counting has been capped at two.
This is part of government reforms designed to make the exams and accountability system more rigorous.
The recognition of some popular unaccredited International GCSE qualifications have been phased out and no longer count for league table purposes.
Overall GCSEs have been toughened with exams taken at the end of the course and detailed changes to core subjects.
What is considered to be acceptable performance at primary level?
This year, primary schools are considered to be "underperforming" if fewer than 65% (up from 60% last year) of pupils get a Level 4 in maths, reading and writing, and pupils are not making the expected progress in these three subjects between the end of infants (age six or seven) and age 10 or 11, when they prepare to leave primary school.
Results of English grammar, punctuation and spelling tests are not taken into account in these floor standards.
How is the performance data presented?
In the past, only media organisations used the data to produce rankings in the form of school league tables.
But now the Department for Education effectively publishes tables, with a facility on its website that allows users to rank schools by different measures.
What happens in the rest of the UK?
Wales and Northern Ireland abolished league tables in 2001, followed by Scotland in 2003. Scottish exam data is still published online.
It is not in a format where schools can be easily compared.
Wales recently began publishing tables placing schools in one of five performance bands.
What are the arguments for presenting performance data in this way?
The performance data in league tables is used widely by parents to judge how well schools in their area perform.
Supporters argue that the tables help drive up standards by increasing the accountability of schools and providing valuable information for parents.
Research carried out by Bristol University suggested the abolition of league tables in Wales had led to a drop in standards in the lowest 75% of schools.
What are the arguments against?
Opponents say comparing schools in this way is too crude a measure of a school's quality, achievements and character.
They argue that the tables often say more about the intake of a school than the teaching and learning that goes on there.
And increasingly head teachers says the constant state of flux in the exams system makes comparisons between not very meaningful.
It is claimed they encourage competition rather than collaboration between schools in local areas and can lead to middle-class parents pushing to get their children into top schools, further driving down standards at less popular schools.
There are also suggestions that children are pushed into subjects and choices that make the school look good, rather than broadening their education.
Should I choose a school for my child based on this performance data?
The tables show how well a particular year group of pupils at a given school has performed in tests or exams. Most of the pupils will have started school a few years before taking the tests or exams and there may have been changes of staff or policy at the school in the interim.
The tables do not include information about the more holistic elements of a school such as extra-curricular activities on offer - for example, sport and drama - or details about a school's pastoral care system.
Some of these details may feature in the school's Ofsted report.
It is always advisable to visit a school - most schools run open days or evenings for prospective pupils and parents.