A couple of weeks back I mentioned that I was reading ‘How would you move Mount Fuji‘ by William Poundstone. It’s an interesting read but no doubt pretty ‘scary’ in terms of the facts it is trying to convey. Poundstone presents not only the puzzles that are offered in interviews conducted by Human Resource departments of ‘talent-intensive’ firms but also a discussion on whether this methods work to hire people that these companies need. He highlighted that companies thinks bad hires are way too high a risk that they would rather risk losing a good hire than getting a bad one by mistake. As a result the interview processes are all skewed towards rejecting people (more or less) and identifying somewhat extraordinary people.
Poundstone identifies an important question HR people should be asking themselves when posing puzzle questions and that is whether the candidate’s response is going to make an impact on your decision to hire or not. If it doesn’t then there’s no point asking the question, like this particular interesting one. Indeed, from a HR point of view, interview time is precious and missing out on good hires is not a pleasant thing either, so structuring an interview to be efficient is very important. If a puzzle can help to bring out key information then it should be used; otherwise, it might just be an abuse of the interviewer’s position.
Well if you’re not interested in the software industry or the finance industry then the puzzles in the book would be nothing more than just a great past-time. This makes Poundstone’s book more interesting because his section of answers to the puzzles given as examples in the book launches into elaboration discussion of how one should approach the puzzles. He attempts to give us some general guidelines on solving these puzzles. He gives nine steps (mainly for interviewees though):
1) Decide what kind of answer is expected (monologue or dialogue)
2) Whatever you think of first is wrong (that’s why it’s a puzzle)
3) Forget you ever learned calculus
4) Big, complicated questions usually have simple answers
5) Simple questions often demand complicated answers
6) “Perfectly logical beings” are not like you and me
7) When you hit a brick wall, try to list the assumptions you’re making. See what happens when you reject each of these assumptions in succession
8) When crucial information is missing in a logic puzzle, lay out the possible scenarios. You’ll almost always find that you don’t need the missing information to solve the problem.
9) Where possible, give a good answer that the interviewer has never heard before
Overall, Mount Fuji is a good read, but I’m guessing most readers would want to speed past the explanations and go straight to the answers themselves. The best puzzles always have the most counter-intuitive solutions and elegant answers. For more practice, you might like to visit some of Poundstone’s reference sites: here, here and here.