They put you in multiple interviews with a range of staff, principals, scientists, engineers, PAs, etc. They ask the standard range of questions. There is no test or quiz, just pointed questions about career goals, skills, your resume, etc. Eventually someone takes you to lunch which is more relaxing. Know your goals, strengths, weaknesses, and know what courses you took in college. Know something about the company as they will as you about it. Know what you like to do at work, and what you don't. Be honest, be positive, be enthusiastic.