Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

news.ycombinator.com

Post reply on HN
Print view View original

1–10 of 363 posts

Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#1

Post by ColinWright »

I was recently chatting with friends and the question came up: When hiring a programmer, FizzBuzz is sometimes (and controversially) used as an initial filter. What's an equivalent filter for mathematicians?

I know that HN is filled with people who have specializations outside of programming, so I ask:

    What is your specialization, and
    what is your "FizzBuzz" equivalent?
Added in edit: Fascinating answers - thank you. I'd love to respond to many of them but that would probably trip the HN flame-war detector, penalise the item, and I'd get no more replies! If you want a reply, email me, or make sure your email is in your profile. And thanks again to all.

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#2

Post by wengzilla »

I was an electrical engineer before I was a computer programmer and people liked asking questions about Ohm's law and calculating total resistance of resistors in series and parallel.

EDIT: I should clarify... They weren't asking about the theory behind Ohm's law but rather to apply it to various circuits.

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#3

Post by ColinWright »

wengzilla wrote: post #2

I was an electrical engineer before I was a computer programmer and people liked asking questions about Ohm's law and calculating total resistance of resistors in series and parallel. EDIT: I should clarify... They weren't asking about the theory behind Ohm's law but rather to apply it to various circuits.

Interesting - thanks. I was hoping for more results, but with this falling rapidly off the "newest" page, and with only one upvote, I guess we won't get (m)any more insights.

Edit: Last minute surge and we're on the front page! Amazing - thanks to those who voted - I'm waiting to see if we get any more answers ...

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#4

Post by ColinWright »

I'm a mathematician, and sometimes I need to assess the level at which I'll pitch an explanation. Although I don't do this in a setting where it's possible to set a test, as such, I do ask this question:

    An equivalence relation is reflexive, symmetric, and
    transitive.  If E is an equivalence relation, and we
    know E(x,y) but we know !E(y,z), what do we know
    about E(x,z), and why?
It seems a great filter for people who can think and reason formally, as opposed to using intuition based on their understanding of the words.

Edited in response to lmm's perfectly reasonable question. In context I would see if they just assumed they knew what I meant, or asked for clarification. If they assumed they knew what I meant, it would be interesting to see what interpretation they used. This is like FizzBuzz - it shouldn't stop with the first draft of the code - it's an opening for discussion.

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#5

Post by PaulKeeble »

wengzilla wrote: post #2

I was an electrical engineer before I was a computer programmer and people liked asking questions about Ohm's law and calculating total resistance of resistors in series and parallel. EDIT: I should clarify... They weren't asking about the theory behind Ohm's law but rather to apply it to various circuits.

That feels more like asking the difference between a class and object. Its not really asking someone to solve nearly the simplest problem to prove they can can code.

Would the equivalent not be making a basic circuit to do something specific and hence a specific example that has one or two potential obvious issues?

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#7

Post by austenallred »

I'm a marketer, and have yet to find a way to judge a marketer's competence better than:

"Here's this app, here's what it does. How would you increase downloads?"

A quick brainstorm session shows you how they approach the situation, what tricks they have in their bag, and what methods they feel confident using (or if they're just BSing).

Interestingly enough, 50% of the time people answer "SEO," which is among the worst answers you could possibly give. The best answers often involve the person playing with the app and figuring out something you could actually build into the app itself.

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#8

Post by walshemj »

wengzilla wrote: post #2

I was an electrical engineer before I was a computer programmer and people liked asking questions about Ohm's law and calculating total resistance of resistors in series and parallel. EDIT: I should clarify... They weren't asking about the theory behind Ohm's law but rather to apply it to various circuits.

Engineer roles or Technician?

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#9

Post by er35826 »

I'm an electrical engineer who has pared my skill list down to 'troubleshooting.' For my equivalent of a fizzbuzz, the exercise is to present someone with a potential failure (the light in the room is off) and ask them how they'd go about investigating the problem.

I like to see all kinds of answers, but particularly more theories are better, especially when justified at least loosely. Things like "change the light bulb", "flick the switch", and "check the circuit breakers" are evidence that they have the right mind for breaking a situation out into many different causes.

edit: I absolutely loathe 'out of the box' as a meme, but I love hearing responses like "is anything else in the room turned on?" as it shows a simpler, more direct way of assessment.

Re: Ask HN: What's your speciality, and what's your "FizzBuzz" equivalent?

#10

Post by lmm »

ColinWright wrote: post #4

I'm a mathematician, and sometimes I need to assess the level at which I'll pitch an explanation. Although I don't do this in a setting where it's possible to set a test, as such, I do ask this question: An equivalence relation is reflexive, symmetric, and transitive. If E is an equivalence relation, and we know E(x,y) but we know !E(y,z), what do we know about E(x,z), and why? It seems a great filter for people who…

"we know not" seems like an unfairly trapped way of phrasing that question; it's not entirely clear that you mean "we know !E(y,z)" rather than "we don't know anything about E(y,z)".
Post reply on HN