Exam board chief executive apologises

Mark Dawe, the chief executive of the OCR exam board which is based in Cambridge, has apologised to students who were given the wrong GCSE and A level grades last year.

In the interview above, he tells our education correspondent Elodie Harper, that measures have been put in place to prevent the same mistakes being made this year. But he admits it's impossible to be a hundred percent sure that all of last year's grades have been corrected.