Ever walk out an interview thinking "I nailed that!", only to discover that you got rejected? Or, conversely, think you bombed, but then you proceed to the next round anyway? The truth is that it's incredibly hard to gauge your own performance in an interview. Usually, when you attempt this, you're looking at one of two factors: the interviewer's attitude, or how many mistakes you made.
Read on for why this doesn't work: Why Your Interview Performance is Impossible to Judge