[hackinthebochs]

I think this is a great interview question, and I wouldn't have came up with the bloom filter answer. The point is the discussion triggered by the question, not any particular answer.

You're taking it like it's a knock on you that he wouldn't 'accept' your answer but lead you down the line of questioning he planned for. But this exactly what interviewers should do: be prepared for a certain line of discussion and nudge the candidate in that direction.

If someone was familiar enough with bloom filters to come up with that answer on their own, that should be an advantage to them. The chances of false negative seems minimal since it's uncommon and I don't think some hack would understand it well enough to use it so appropriately after a cursory glance at a wikipedia page.

On the other hand, the discussion is more important than the answer so the person spouts off bloom filter immediately is short circuiting the very process he's there for. So it balances out either way.

[Stormbringer]

I like many others thought that this was a terrible interview question.

On the other hand, I learned something today (probabilistic data structures?!? WTF?!?)

I think the fundamental problem with the question is that it is the wrong way round. It is designed so that the interviewer can show off his expertise, whereas traditionally the view would be that you need to get the person being interviewed to show off their expertise.

Of course, if what you are really interviewing for is people who will bask in your awesomeness, then it is ideal.

----

I had a really weird interview this week. I couldn't get a word in edgewise. Haven't heard back from them either. Bizarre. If you're not going to let me talk, what is the basis for rejecting me? :D

[hackinthebochs]

I don't get where this question shows he's trying to "show off his expertise". I can see that some people might be sensitive to the situation having been through the type of interview you describe. But I think its going too far assuming thats his motivation for this question.

I think the best types of questions are the ones where you don't know the answer ahead of time. This is where you really get to see how someone thinks. The bloom filter is rare enough that its likely people won't have any exposure to it at all. This gives you a very objective look at how quickly people can grasp new concepts and then apply them. This is exactly what an interview should hope to discover about a candidate.

What I see in the responses to this question are people who aren't very interested in the science side of computer science and thus immediately get suspicious when a question heads in that direction. Perhaps unfortunately, questions like these are going to be biased towards someone who does have a high interest in it.