Lets say a particular exam was really hard and everyone in the state performed badly. Does that mean that that subject scales higher? For example P90 last year mark was 91 and because of an hard exam P90 is 86...will it scale higher?
You can't say this because what if the cohort was not as academically smart? It does not always mean the exam was harder if students did not perform as well as the previous year.
A simplified way of how scaling works is comparing performances of the different subjects.
E.g. We have players from different sports, tennis, table tennis, squash and badminton. Let's say they sat their respective matches (exams) and received the following:
Tennis: 65
Table tennis: 87
Squash: 70
Badminton: 74
We cannot simply scale tennis up or table tennis down because we can't determine the difficulty of the matches by judging on one test. So what if we asked all players to play an external match not favouring a sport (English Exam) and these were the results:
Tennis: 93
Table tennis: 82
Squash: 84
Badminton: 87
As you can see the tennis player was superior despite performing the worst in his tennis match. Thus it is evident that his match was harder than the other sports, hence scaling comes into play. What UAC essentially does is that it does this comparison across all subjects. All scaling data is found on the UAC website.
