When marking an A-Level examination a few years back I was surprised that we had to be so lenient with one particular question and credit incorrect answers with a mark, despite the answer demonstrating a fundamental misconception of the physics. I cannot remember what the question was, or what incorrect answers I had to credit with a mark, but I remember being perturbed by this. When I discussed it with my line manager at the Examination Board, they remarked that, ‘everyone has to get marks somewhere. Even a candidate on track for a Grade E has to get some of the marks.’
I suppose this makes sense. There must be a spread of marks to differentiate between different candidates. It cannot be the case that candidates who understand the physics get full marks (and therefore an A*) and candidates who do not understand the physics get zero marks (and therefore a U). After thinking about this long and hard (by which I mean, maybe for a minute before typing this nonsense), I reckon that there are three ways Examination Boards ensure that there are a spread of marks.
1. Scaled question difficulty
This is the most sensible approach to take. Including some questions that are easy and some that are hard is not enough, there should be a continuous gradient of difficulty, so that the subtle difference in ability between two similar candidates can be fairly determined. Examination Boards do try to use this strategy, with varying levels of success. The AQA A-Level Physics Paper 2 from 2024 was a notoriously challenging paper. When I attempted it myself I was unable to finish it within the allocated time. Whilst it is certainly true that less-able candidates would be expected to score lower than more-able candidates, I feel that the balance was off. In other years the paper has been more straightforward, and some years the paper is mostly straight forward but with one significantly more challenging question.
The ideal continuous gradient of difficulty for each topic is the gold standard, but realistically it is impossible to achieve.
2. Variable leniency when creating and applying the mark scheme
The second strategy to produce variation in marks is by changing year-on-year what physics is marked strictly, and what physics is marked leniently. This can be difficult to predict, and it makes the use of mark schemes in revision problematic. If you are revising by using a particular paper and question, you may find the mark scheme allows an answer that would not necessarily be allowed in a different year on a different paper. This can add an element of randomness to the marks awarded, and thus provide the spread of marks. This strategy rewards students who revise from a broad range of papers – as many as possible – and who try to develop the skill of giving as much detail as possible so that the stricter mark schemes are satisfied. Students can never know exactly what is necessary to get the marks, so those who only revise from a small selection of papers and see that some aspect of physics is marked leniently one year may think that that is the standard required, but that isn’t necessarily so for the next year.
3. Variable expectation of workload per mark
The third strategy is perhaps the most infuriating. Whilst strategy 1 rewards good physics, and strategy 2 rewards good revision, strategy 3 seems entirely random. On some questions, a calculation may be worth three marks. On some questions where the calculation has the same number of steps and the same complexity, it may be worth two, or maybe just one. How can a student predict how much working they need to show or how many steps are necessary? Simply put: they cannot. This strategy adds an element of randomness to the distribution of marks, helping the Examination Boards get a spread of scores, but the spread is a consequence of inconsistency, rather than student ability or preparedness.
So what can students do?
How does this information help students? It shows that there are two key strategies to doing well: know the physics, and know the Examination Board idiosyncrasies. Students can develop their understanding of physics using platforms such as Isaac Physics. They can develop their exam technique by using as many past papers as they can get their hands on and always assuming the strictest application of the mark schemes. As for the students’ scores, there will always be an element of randomness to them too. The trick is to get such a high score that the random noise doesn’t not bring the student’s grade below a grade boundary.
That is easier said than done, of course. If A-Level Physics was easy, everyone would do it. If you are considering your A-Level options next year, this video may be helpful.
Do you think the Examination Boards do a good job of getting a range of marks by using a continuous gradient of difficulty, or do you think they get it wrong? Let me know in the comments!
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