Weekly calibration and switch to the 2024+ mastery display

Every Monday, I recalibrate question difficulties and student mastery estimates using the latest available response data. Your mastery may therefore move slightly up or down, even if you have not completed another paper. This reflects an updated estimate of your ability; your submitted answers and raw marks remain unchanged.

Today, I also switched the default mastery display from the 2017–2023 scale to the estimated 2024+ equivalent, which I feel is more relevant to students preparing for the current exam. The 2017–2023 figure is still available.

Together, these two changes may have caused a noticeable shift in the mastery shown on your dashboard. I am sorry if this caught you by surprise! Nothing is broken, and a lower displayed number does not mean your ability has suddenly dropped. In hindsight, I should have staggered these changes and explained them beforehand.

Read more: Why your mastery may change on Mondays.