How scaling is done by UPSC
(article by kushal)
Moderation is done not only in the subjective-type main examination but also in the objective-type preliminary examination.
Although multiple choice question papers can yield full marks in any subject, UPSC applies scaling at the prelims stage for two reasons: the variations in the inherent difficulty of various subjects and the variations in a given year in the difficulty of each question paper.
At the main examination, there is a third reason as well: inherent subjectivity of the different examiners dealing with the same subject. To ensure uniformity, examiners of each subject meet before evaluating the answer books.
After the evaluated answer books are returned by the examiners, their head conducts a random sample survey to verify if each of them has followed the norms. If any examiner is found to have deviated, then the head examiner makes alterations to achieve uniformity in valuation.
The quantum of moderation applied by the head examiner is proportionate to the degree of liberality or strictness in the marking done originally by the examiner.
Besides striving for uniformity in valuation, UPSC applies moderation to bring about uniformity even in the difficulty of the 50 odd subjects that are offered as optionals in the mains.
UPSC considers “the statistical position of each subject”to find out if the question paper in a given year has been easy or difficult. It accordingly does “statistical moderation by linear transformation wherever considered necessary.”
The marks obtained in the prelims are not disclosed since it is anyway meant to be only a “screening test.”Besides, the disclosure of marks awarded in the objective type test could easily betray the moderation formula.*[Sourse: TOI]*
This formula in effect scales down any Subject specific bias. The only underlying factor would be you being good in your subject.
