The biggest impact on this year's GCSE results have stemmed from changes that mean students did not sit exams early, compared to previous years when pupils could take GCSEs multiple times, exam chiefs suggested.
This year, only a teenager's first attempt at an exam would count in school league tables, so schools that had traditionally made use of the winter exam season, entered pupils early, or made use of resitting are likely to have seen the greatest changes.
There has been a significant amount of change to the system this year and although UK level figures are relatively stable we expect more schools and colleges to see volatility in their results. The extent of this volatility will depend on how much change from their usual practices they experienced and how they adapted.
Entry patterns are very different this year. We have seen a dramatic decline in the number of entries from 15-year-olds, which is largely due to a change in the school accountability measure, where a candidate's first entry counts in performance tables, and the move to end-of-year exams in England.
As we would expect, where the change in entry patterns is greatest, such as the sciences, English and maths, we have seen some impact on results. But despite these changes and the potential for increased centre volatility, candidates can be confident that standards have been maintained.
More top news
Some of those killed in the warehouse blaze sent final messages to loved ones saying "I'm going to die" and "I love you", it has emerged.
The mistake was down to facial recognition software on a computer - but Richard Lee says he is not taking it personally.
The prime minister's outfit for a magazine profile raised eyebrows among some MPs.