I originally interviewed with RTI over the summer. The interview process consisted of a phone screen, followed by an on site panel interview with about six people. In both interviews the questions were a mix of situational/behavioral and specific technical questions. They were all very polite and positive and gave the impression of being a very cohesive group - I was asked questions by my direct prospective peers as well as the manager of this entire work group. They also gave me a very positive impression of the culture, degree of formality between them (somewhat informal) and the workload. I found it really thorough and informative