Interviews are not all the same.  Depending on your career field, the interview stage, or the type of organization, interview meetings can widely differ.  To meet interviewers unprepared is like to give a presentation without rehearsal.  You would never do the latter, so why would you do the former?  Although this may sound obvious, too many job applicants still underestimate the preparation required in order to have a successful meeting.

The first thing to do is to know what type of interview you will be attending.  If you are told beforehand regarding the particulars, that's perfect.  Otherwise, don't hesitate to contact the recruiter to ask for specifics.

Knowing the interview type in advance is knowing the rules of the game.. in advance.  Don't forget, an interview is nothing more than a tournament.  The winner gets the job.  Any strategic advantage counts.