evaluation techinque
I'm not too sure if people are aware how the Civil Services' exams are evaluated. They pull out the answer scripts for 1 of the many exams attempted and check them, on the basis of which candidates are eliminated. Then move on to the next test to further downsize the number.
For instance, out of the 5 exams we appeared for, they would choose 1 particular test and evaluate the same for everyone with a bench-mark set. Eliminate the people who don't qualify and then start afresh with the next paper. This process quite obviously cuts down on a lot of time.
Of course this is just a speculation and no one knows for sure how they would go about it.