I applied through college or university. The process took 1 week. I interviewed at MIT (Cambridge, MA) in Apr 2015
Interview
You can contact any professor whose research you are interested in or search through the listings on the UROP website and then contact the supervisor from there. After responding, the supervisor will probably set up a time for an interview so you guys can discuss your interests in the research and what you can contribute. They will also make sure that you might all the requirements for the position and will probably ask you to send them a resume that you will discuss at the interview.
I reached out and had a short discussion with UROP supervisors, and it was a fairly smooth process. It was helpful that I luckily reached out to a very nice mentor who was accepting and encouraging.
Very casual for undergraduate positions, mostly conversation about past experiences, relevant skills, and a couple of technical questions to demonstrate your knowledge of the relevant field of research to which you're applying.
Interview questions [1]
Question 1
What are the benefits of one hot encoded vectors vs embeddings for training of a ML model
I applied through other source. I interviewed at MIT (Boston, MA) in Jan 2020
Interview
The interview process is kind of informal, with no real channels to get to cool research. You have to know or reach out to some professors in order to really get going.