Source: Have interviewed with Google a couple of times, and coached a couple of other people for the same.
Even better is to use that rapport to then disguise successively large hints into the interviewing process, so the candidate can't obviously tell if they've failed horribly... again to avoid tilting them for future interviews that day. Give them room and time to explore the problem space on their own, but don't let them sit in silence making no progress for 30 minutes making it painfully obvious that something is very wrong.
A single bombed interview might not kill the whole packet, so it's best to insulate.
> I file feedback exclusively on technical merit and communication.
I appreciate your comment, but my point is that there's no way to actually do this, even if your goal is to. It may seem that you're being objective, but the objective facts can only influence the subjective opinion that's ultimately responsible for the decision, not the reverse as we like to think.
For example, if an interviewer likes the interviewee, they would actually think that the person did quite well in the technical question, and not if they don't. We first form an opinion about someone or something and then look for "objective" facts to justify it, not the other way round.
The only way to really be objective here is to use a point system and hard thresholds which completely removes the human in the loop, like SAT.
I recommend "Thinking Fast and Slow" and "Why Buddhism is True" which go into this idea in detail, and in general about how poor we are at being unbiased and rational. You'd be surprised at how deep our irrationality goes even if you already have some idea.
Sure, what is included can still be slightly biased, but if you're talking about non-technical things at the beginning or end, it won't really make it into the technical interview feedback, and probably will have little to no effect on the committee's decision. At the end of the day, the problems you're asked have optimal solutions and your code will either work or it won't.
I don't think your point is totally off base, I just think you stated it too strongly in your previous comment.
There is no such thing.
> but things like your sense of humor, ability to communicate in a positive and cheerful way, whether you seem mature and responsible, and other such little things the typical techie would like in another person.
Sounds like you're hiring actors rather than people able to do good technical work.
Google as a company seems to have none of these qualities in the aggregate so it looks to me as if your process is broken. Besides the obvious ethical challenges.