The Importance of "I Don't Know"

When interviewing people, one of the biggest things I’m looking for is someone to say the words “I don’t know.” It doesn’t have to be that exact phrase, but it should be something similar, “I’d have to do some more research,” or, “I’m not sure but I’ll look further into it.” It doesn’t necessarily have to be the person being interviewed, it could even be who is actually conducting the interview.