AS-level results are expected to be more varied this year, and schools and colleges are being warned to be prepared for this outcome by exams regulator Ofqual, the BBC reports.
They are this year being de-coupled from A-levels, meaning that a variation from the 2015-2016 results is expected.
In a blog post, Ofqual associate director Cath Jadhav said: "We know that students tend to do less well in the first year of a new qualification." She added that it will take time for both teachers and students to get to grips with the new system.
Now that AS-level results don't count towards the final A-level grade, the exams regulator is also anticipating a higher take-up of courses at the lower level, with students now being able to choose to end their education after this stage.
With this in mind, Malcolm Trobe, interim general secretary of the Association of School and College Leaders, has explained that some schools have decided that students aiming for A-levels will skip AS-levels altogether.
Ofqual will rely on statistical predictions to ensure students are not disadvantaged by being the first cohort to sit the new linear AS qualifications, Ms Jadhav explained in her blog.
She said that "exam boards will need to be able to justify any grade boundaries that are different from those suggested by the predictions". However, she went on to say that appropriate checks and balances are being put in place to ensure that students are not disadvantaged by the new system in any way.
This step was taken for 13 subjects in the year that has just ended, and will be rolled-out to more in September.