It doesn't happen often, but you may encounter an applicant who is difficult to deal with. This person may try to monopolize the interview, be unable to answer most of your questions, make snide remarks about the questions you ask, or beg you to give her a job.
Turn the situation around at the first sign of an interviewee trying to lead the conversation. If you ask about the things at her last job that she enjoyed most and she spins off into a story about a coworker who throws a great Super Bowl party each year, it's time to take control. Say that you would like to hear more about the party, but it's time to focus on the interview, then quickly ask the next question. An interview is a two-way conversation, and doesn't mean that you do all the talking and the applicant speaks only when asked a question. But when the discussion strays off topic and is unproductive, it's hard to properly evaluate the candidate.
If an interviewee has no answers to most of your questions, you may wonder why she is there in the first place. She may not really want the job and was pressured to apply by a parent or spouse, her work history may not really be what it appears to be on paper, or she may simply not know what to say. You can help her out by answering one of the questions yourself to give her an idea of what you are looking for. If this doesn't help, finish the interview as best as you can.
It is a good idea to ask identical questions of each person who applies for the same position. This gives everyone an equal opportunity to sell him or herself and will protect you if you are accused of being discriminatory. Prepare a template of your questions and print one for each interview, writing the applicant's answers below each question.
When you receive a snide remark about a question that you ask, ensure the applicant that you are asking all applicants the same questions, others have answered it, and you feel that it is a fair question. Give the person the opportunity to skip the question and go on to the next, and indicate his response in your interview notes.
It's hard to avoid being pulled into someone's story about how much they need a job. There can be a personal or financial hardship that places the candidate in a tough situation, but this should not be brought up in an interview, though it does happen. When it does, a simple, “I am sorry to hear that you are going through a tough time right now. Looking for a job is a wise choice,” and proceed with the interview.