Union Public Service Commission :?
The guy who sets the paper is Chief Examiner as well. He has few additional examiners under him. The evaluation criteria for answers are discussed between AE's and CE. The papers are corrected and from the stack a random sample survey is done by CE. If huge difference between CE's marks and AE's marks, the paper is re-evaluated. If difference is moderate, that amount of moderation is applied to all papers evaluated by that AE. That's how it runs. Sometimes when you have many papers under you, you have a series of CE's and a head CE and process happens. You can read about it on UPSC website, court cases in Sanjay v/s UPSC if I remember properly.