I was fortunate enough to receive a STAR questionnaire from my interview committee. For those unfamiliar with STAR, it is an acronym for Situation Task Action(/Assessment) Result. Not all interviews are STAR based, but a few others on GLASSDOOR have mentioned the same interview type quesions and so did the other interns.
The most important thing in these type of interviews is simply CONFIDENCE. You may be very nervous, which is normal, but try to keep it under control. Simple advice to calm nerves, trap one hand between your crossed over legs. This helped me from shaking my legs and twitching my hand. Remember, these are normal guys who talk smack and drink like the rest of us. A person who seems more down to earth and relaxed are much more approachable and easier to like. In the same token, people don't want to hire someone who looks or sounds weak. Second, answer questions slowly and methodically but do not be overly repetitive. When you finish answering one of their questions early, simply say "That's about it." Also, MODESTY comes a long way. For my position, they were looking for leadership material but most importantly a team member that can get along with the group. Be friendly but respectful during the meeting. Using Sir or Madam can go a long way.
Not all answers to these SITUATION questions need to revolve around your Major/Profession. However, this is somewhat of a gamble. I no longer wanted to sound repetitive talking about my Senior Design Project for the 3rd or 4th time so I talked about my Summer Basketball Team instead. This was in regards to "How would you resolve a conflict between members of your group." I brought a situation and presented how I solved it. After the question was over, the hiring manager smiled with a slight laughter and asked "did you bring up basketball because you knew I was a huge Laker Fan?" I told him I had no idea and he told me to turn around and look at his mural of Laker accessories. This brings up my next point, BE AWARE of your SURROUNDINGS. My boss (at the time) still jokes that if it wasn't for that answer I would be working elsewhere.
It takes between 2 to 4 weeks for results from the interview to come in. There is generally only 1 interview process, but if candidates are close in competition, a 2nd might be asked for.
The Internship was offered and I accepted. 3 months later, I was hired full time and transferred to another department.