'Coasting Schools' Attacked in the Latest Ministerial Balls-Up

The Government is tilting at windmills again with a ministerial attack on imagined weak schools. Ed Balls, the Schools Secretary, has decided it is time to tackle good schools for not being good enough. The press release says

Ministers are taking action after analysis shows that one in seven pupils do not progress a whole attainment level in English between the ages of 11 and 14. Until now ‘coasting’ schools have often missed out on focused attention and have been hard for parents to identify because of apparently satisfactory results.

This is appallingly wrong-headed for two reasons.

The Limits of Testing

First, it is in the nature of the tests that some pupils are awarded the wrong level. If everyone advanced by a whole level in their understanding, then the limited reliability of the tests would mean that a third will get the wrong level (or, about one in six would appear to have stood still for three years.)

A year ago The Primary Review, an independent two-year long enquiry into primary education in England, reported in its research survey Assessment Alternatives for Primary Education that

Regardless of the consistency of individual test items, the fact that a test has to be limited to a small sample of possible items means that the test as a whole is a rather poor measure for any individual pupil. This is because a different selection of items would produce a different result. Wiliam (2001) estimated the difference that this would make for the end of Key Stage tests in England. With a test of overall reliability of 0.80, this source of error would result in 32 per cent of pupils being given the wrong level.

This made a big splash at the time, for example here in the Guardian.

'Value Added' Scores

Second, the coasting schools will be identified if they meet any of a list of criteria given in the same press release, including if

• The school’s Contextual Value Added (CVA) score is significantly below average;
• There has been little or no improvement in the school’s progression rates over several years;

So a school that is consistently doing well needs a kicking if pass rates don't go up year on year, or if that school's particular challenges don't feature in the CVA ranking model. OFSTED, England's schools inspectorate, themselves say that categorising schools on the basis of CVA scores is "meaningless", as described by the BBC news item last August:

… in an example OFSTED gives it may appear that a school with a CVA of 1,009 is doing better than another with a CVA of 992.

"However, that would be incorrect," [OFSTED] says in new guidance to schools about the use of data. "In both cases, the range between the upper and lower confidence limits includes 1,000, so both schools are achieving average outcomes; their performance is about as expected."

The guidance adds: "No meaning can be attached to an absolute CVA value, and any ranking of schools by their CVA values is meaningless."

Homework for Ed Balls

Ed Balls needs to visit schools, not to "target" them (a rather aggressive term for what should be a supportive programme), but to study some maths. It is a shame that Mr Balls learned enough arithmetic at school to manipulate figures, but did not make a sufficient study of how to handle anything but the simplest data.