Interviewing is a job that demands not only writing skills but people skills. Preparation is crucial.
As a journalist, the main purpose is usually to elicit information, and knowing in advance what questions to ask ensures that the job is done right. But getting information is not nearly enough. It's also necessary to create interesting reading, often taken from people who may be neither informative nor interesting. To conduct such an interview is a different skill than simply writing well.
These interviews are drawn from two sources: for some, I conducted the interview myself. For others, I was given a tape and instructions on what kind of article was desired.