If I had to guess, I would say I conducted at least 100 phone or in-person interviews last year and all of the onsite interviews followed the same standard format:
1. Three or four lead developers, the interviewee and I sit in a large conference room.
2. Per our request, the candidate spends 3-5 minutes telling us about themselves.
3. The leads and I then take turns asking the candidate both technical and team-oriented questions.
4. When I get the sense that the team has had adequate time to make a hire/no hire decision, I ask the “cube question.”
5. Finally, we give the candidate some time to ask us questions.
So what is the cube question? It’s something I was asked in an interview years and years ago and I’ve never forgotten it. “How many sides does a cube have?” That’s it. Simple, yet surprisingly 40% of our candidates answer incorrectly. Honest. My guess is that most interviewees figure it must be a trick question and they over-think the answer. Others are probably so focused on answering the technical and team-oriented questions that they aren’t able to get their brain to chew on anything else. A small portion probably just have no idea what it is I’m asking.
When it comes down to it, the question, well, more importantly, the answer means nothing to me. Whether the candidate answers right or wrong, it is a nice way to wrap up our Q & A session and let the candidate ask us some questions. Not surprisingly, the bulk of the time, the candidate’s first question is “Did I answer the cube question correctly?”
When the candidate does give us the wrong answer, we sometimes ask for an explanation. We’ve gotten reasonable explanations why one would answer 8 or 12, but one candidate answered 35. When we questioned him, he said, “In his world, a cube has 35 sides.” We hired the guy and he ended up being one the most fun, crazy and talented coders around and we still laugh about it today.
[ I've had this post in my queue for a while now. I had to get it out there today after reading Jim Martin's post, You Don't Bury Survivors. Read it. It's fantastic. ]
I’m not surprised so many get that wrong, especially in a stressful situation as a tag-team technical interview. If the interviewee is told to take his/her time, hopefully most will get it right.
But the first answer that pops in people’s head is 4. Because the human brain doesn’t actually handle 3-D all that well. When you think about it, you see in 2-D. Luckily, if both eyes work, you get the stereoscopic effect that makes things “appear” 3-D. But if I’m looking at you, I can’t see the back of your head. It’s still a 2-D image.
Another good question is how many 1-inch sugar cubes would it take to make a 2-inch sugar cube. Again, most people instinctively answer four. I bet even more people would get that one wrong.
[...] Yes, they are sometimes the you-don’t-bury-survivors type questions. And then there’s the cube question which I have written about previously. One of the guys on my team likes to ask “port [...]
personally, I’d answer 2 – inside and outside
)
but, then again, I like the 35 one
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