I had an interview once that had me complete 3 small tasks on my own: a debugging task, a database task, and a small web site. All three had to be completed in under 2 hours. I wasn't given much direction, other than the specs of the 3 tasks.
While I think this was a moderate evaluation of my skills, it ended up being more a test of if I could complete the tasks on time, vs. the quality of my work: I ended up not making it to the next step of the interview because I was too concerned about quality code over actually completing the tasks (with mediocre code), and didn't complete the tasks, thinking that they would rather get a feel for my quality vs. if I can complete a task. I did it remotely, so they never really got a feel for my character or personality.
Had it been in a paired session, things likely would have gone differently. However, I did learn more about where their priorities were, and ultimately feel I probably would not have been a good fit.