I had to interview a contractor last week and it did not go well (for him). He didn't know a lot of things like Linq, session management and ASMX/WCF. After the interview, I expressed surprise at this, saying something like "I didn't think a contractor would get stumped at those basic questions." My coworkers said, "Of course, it makes sense." Then we had a debate (catfight).

My coworkers said that contractors aren't really supposed to think for themselves. All they have to do is what they're told, so they don't have an incentive for building up their knowledge. They can pick it up as they go along.

I said that contractors need to keep up and build up their knowledge because they're working for so many different people, so their knowledge has to go from (example) Win32 APIs to WCF to ParallelFx. Anything and everything - that's the only way they can work for different organizations.

So my question to you is - based on your experience with talking and meeting other contractors, who is right? Me or my coworkers? I have more interviews with contractors coming up - should I seek out methods to relieve my blood pressure?

Before you answer, please keep in mind that my coworkers like to kick puppies and push old ladies down the stairs.