It's for research, specifically at an FFRDC. I don't believe there's any sort of "establish your technical skills" portion. My hiring process was a bit unique because I had already worked as an intern for 3 years, but as I understand it the usual process is 1) hiring manager finds the best resumes, 2) hiring manager does a phone interview with those people, and 3) hiring manager invites a few of the best prospects out.

The real technical skills part is the presentation. If you can give a good, 40 minute talk about what you've been working on, you've already put yourself in a good place.