Beat me to it. When I interviewed at Google there were multiple interviewers and then there were multiple committees and people who look at their feedback.
Comparing interviewers to other interviewers makes a "He did above average" from a person who's hard to impress as good as a "She did really great!" from someone else.
Comparing interviewers to other interviewers makes a "He did above average" from a person who's hard to impress as good as a "She did really great!" from someone else.