Smart_Dunce said:
What about difficulty of the subject?
Lets say there's two kids- marks are same as each other's in english, modern history.....
kid A gets 90 in general maths, kid B gets 90 in 2u maths,
assuming both kids are placed in top 10% of state, why would B get a higher uai than A?
Difficulty is not a direct consideration in the scaling process.
The reason that a raw mark of 90 in Mathematics 2 unit is better than a mark of 90 in General Mathematics is because Mathematics 2 unit scales better than General Mathematics and also, General Mathematics is often capped.
There is not much information and it is beyond my understanding and knowledge in how the scaling of a course is determined algorithmically and numerically. Perhaps, Lazarus (James King), the administrator of this site could tell you.
To determine the scaled mean and standard deviation of a course, which I guess also suggests the nature of the scaling for a particular course, the overall academic performance of students in some of their other courses is measured and taken into consideration. For extension courses, the performance of these extension students in the corresponding 2 unit course is considered in the scaling algorithm. For the case of Mathematics Extension 2, the performance of these Extension 2 students in the Mathematics Extension 1 course is also considered.
The UAC Technical Committee on Scaling has not revealed a lot of specific information about scaling, especially any actual calculations in the scaling process. The information provided by them anyway is often difficult to comprehend for most people. Perhaps this part should be best left alone for the moment.