No state has completely pulled out of Common Core, but Utah and Alabama have backed out of the consortium of states working to create computer-based Common Coreexams.
In Kentucky, the first state to replace state exams with tests based on Common Core, the percentage of students meeting math and reading goals dropped by about one-third last year.
The new GCSE qualifications, for courses starting in the autumn 2015, will be drawn up by exam boards for approval by the exams watchdog, Ofqual, in the core subjects English, maths, the sciences, history and geography.