Remain poised and confident. If every other rule slips your mind, be sure to remember this one. Interviewers are not always human resource professionals and may be as nervous or uncertain as you. They might ask a series of difficult questions, repeat a question, challenge your answers or appear not to listen. No matter which particular challenge you are faced with, strive to keep your confidence up.
Silence is the most common stress producing occurrence during an interview.
Try not to chatter needlessly if silence is used. Break the silence only to ask a question or volunteer relevant information. On the other hand, if your interviewer is obviously uncertain of what to ask, you may want to direct the interview and present some information you feel should be discussed. If you have prepared well, including assessing your own values and skills, you can trust your responses. You are evaluating the organization, as well as being evaluated by them.