They will send you emails of technical questions to be answered. There are 2 series of these, once you finished one, you will be emailed another set of questions to be answered. These might a bit hard. But I believe these would set you an interview if you answered them they way they want. After completing both series, you will be notified by a email of getting an interview.
The interview I had was on campus at University of Houston. I applied through the companies website, and was listed to be interviewed on campus. You are able to select what time is right for you.