For Chemistry and Biology AS, I did the AQA exam, but for Physics, our school for some reason chose OCR, and it was brutal. Their mark schemes expect you to come up with very general statements which have very little relevance to what the question is asking, and some definitions are just ridiculously specific and they don't credit you even if your definition is right, for example, for the question "define an emission line spectrum":
- "a series of coloured lines against a dark background" gains one mark;
- "a series of coloured lines corresponding to wavelengths emitted by excited atoms" apparently gains no marks.