I applied through university. The process took 2 weeks. I interviewed at Boston University (Boston, MA) in Aug 2015
Interview
Two professors vs. one candidate, including general talking about the responsibilities, skills review, project experience, and some analytical background. Also I made a short presentation on my project experience by unfolding some detailed background information of the project, and the timeline of the progress of the project I've done. Some programming skills were asked and tested.
Interview questions [1]
Question 1
What kind of programming skills do you think may be beneficial to our project working
Individual faculty interviews with principal investigators where they ask you questions based on your experience and their own background. They try to match based on which program you want to join. Current students facilitate getting you to and from each interview.
Interview questions [1]
Question 1
Describe undergraduate research challenges and how you overcame them
Submit the application through the system, and waiting for the response. After the interview, you will get the result soon. It would be better if you could get a referral from your friend or classmates.