[eric-hu]

That does seem to be an interview technique used at some companies. It comes with its own set of problems, though.

What if someone asks a friend for help or pays someone to solve the problem in its entirety? If your problems aren't unique enough, they could also google the answers.

With that said, I actually prefer your approach. Its pitfalls have to be weighed carefully; hiring someone who knew enough to fake it could be a costly setback for a small company. However, it does remove some unnecessary pressure from the interview process.

[dr_rezzy]

That would only be a risk if we were talking about a typical high school multiple choice test. I would think that a cheater would be filtered out by this point in their career (this point being applying to a high tech company). However, collaborating on a solution is not necessarily a bad thing. I think the goal here is to find candidates which can deliver unique, valuable, and insightful problem solving skills. To go ahead and bottle that process up into a pre determined steps or a 1 hour drill doesnt serve your goals very well. Who knows, maybe these guys have a recipe which works for them. From my own experiences, I would disagree.

[regs]

You'd be surprised at what people will do to game an interview. I've had people give me the correct answer to a question I didn't ask (but from our list of questions) - clearly having gotten from someone else who had interviewed earlier.

Note that algorithms interviews are just one part of a larger inventory that one takes of a candidates, one dimension. Take home and/or whiteboard coding can be a part of that process as well, but each has its downsides.

What we look for, in particular, is methods that have a very low false positive rate. In person algorithm interviews, where the point is not the 'right' answer but hearing about how someone thinks are in that category. You can't really fake it.

[nvarsj]

Apple does something very similar (or at least used to). They give a difficult algorithmic coding problem and a few days to complete it. Then they grill you on it at the on site interview. There is no way you could fake explaining it - you have to really understand what you did.