Make the participants aware of your intentions.
Let the participants know that you appreciate their taking part in the interview and that their responses to the interview questions are valuable to the overall design project.
Make sure everyone understands that you are the official arbitrator if and when a dispute arises.
Conduct the interview in a well-lit room, separated from distracting noise, with a large table and comfortable chairs, and have coffee and munchies on hand.
Set a limit of 10 people or fewer for each interview.
Conduct separate interviews for users and management.
When you have to interview several groups of people, designate a group leader for each group.
Prepare your questions prior to the interview.
If you're not very good at taking notes, either assign that task to a dependable transcriber for each interview or get the group's permission to use a tape recorder to record the interview.
Give everyone your equal and undivided attention.
Keep the pace of the interview moving.
Always maintain control of the interview.