Setting out a "rapid response" to the data, Sir Michael promised the watchdog's survey would investigate fears that some of the brightest secondary school pupils are being let down by teachers who fail to stretch them to get the best exam results.

BBC: Ofsted chief voices fears for brightest pupils

Every year through to Grade 12, we sit three exams at the end of each term for every single subject, and the final term exam we have to pass (and pass it well), or we fail and we would have to repeat the year, while some of our friends move on.

BBC: Exam overload: Are you getting stressed out?

For test-takers who fail a section, the computerized version provides details about what skills they need to work on before retaking the exam.

WSJ: Some states dropping GED as test price spikes