I got the grade for one of my masters modules recently, a presentation, marked by two people. I got to see each marker grade. This was a mistake and I have been told I should have only got to see the combined agreed grade. There is a difference of 8.5% between the two marks. It's made me think about how subjective grades can be. Apparently, the difference has been known to be much bigger than 8.5% for some other students.