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

Wacky interview questions

geekwire.com

Post reply on HN
Print view View original

41–50 of 60 posts

Re: Wacky interview questions

#41

Post by fishtoaster »

MattRogish wrote: post #14

These aren't just wacky, they are stupid. "How many ping-pong balls can fit in a VW bus" is just about the worst question I've ever gotten. Little or no relation to software development. Here's what we do. Interested in feedback, please! Via the phone: * A few background questions (why are you looking for a job, what sounds interesting about what we are doing) (20-30 minutes) * A bunch of topgrading questions http://…

I see a little value in "Fermi problems" like ping pongs in a VW bus. I use one like it on a candidate's second call (first call with an engineer; takes place after our on-site recruiter has screened tehem). The point is to see how they handle a relatively intractable problem. The only real wrong answer is either a refusal to come up with an answer or an off-the-cuff guess with no explanation. If they at least try to extrapolate an answer from reasonable assumptions, that's fine.

To your process, my thoughts:

- Open-book challenges like you describe (in which you can use stack overflow and whatnot) are awesome. However, why do you have them do stuff they're not expected to know? From what I've read, the only thing hiring studies seem to agree on is that the questions which best predict a candidate's long-term success are those that simulate what the candidate will actually be working on. Getting them to learn outside their comfort zone is good, but maybe you'd be better off doing that by finding problems you've actually had in the course of your work that are outside of their comfort zone.

- Short-term contracts are tricky. On one hand, I think they're the best way to test how well a candidate will work out. On the other hand, switching jobs is a lot of work and stress. If I had a choice between two pretty good companies, one of which was a 1-month contract and one of which was a normal job, I'd definitely take the latter. If I had to move to get your job, it'd make rejecting such a proposal even more of a no-brainer. If it works out for you, that's great, but I'd be really worried about losing excellent candidates.

- It seems like your remote screening is lighter than what I'm used to. At my current gig, we send candidates a challenge to be completed in their own time (3-9 hours of work)- we've found it's a great prelude to the phone screen with an engineer. It's pretty much a code sample for which we have an excellent reference (all the previous submissions). We've found it improves the quality of candidates that get to our on-site.

Re: Wacky interview questions

#42

Post by Domenic_S »

orangethirty wrote: post #34
crntaylor wrote: post #33

Earlier quoted context omitted.

AM or PM? It doesn't matter.

Of course it matters. The ask to make the calculation when its 11:50. I need to know if I'm free to be able to go and calculate it at exactly 11:50. I would not want to do the calculation at 11:49 or 11:51, because then I could be missing another calculation appointment. Using when implies that I do the calculation at the exact point in space-time, and not calculate the angle of the clock pointers at the moment the c…

You must be a blast at parties.

Re: Wacky interview questions

#43

Post by doktrin »

orangethirty wrote: post #32

M$: 1.Define diaper. As in adult, children, paper, cloth, etc. 2.So it doesnt fall down the hole it is covering. Amazon: Depends on how much PHP I have to write. Google: Define cow. Does it only apply to the common animal or does it also apply to the slang used to refer to overweight people? Zillow: Define success. Expedia: Which language version for the T9 keypad? In what language do the words have to be found? “If…

>“Estimate how many windows are in New York.”

>Are we refering to regular windows or computing devices running the operating system Windows? Plus, define Window. Is it an opening in a wall? Does it need to have a glass plane?

>“How would you direct someone else on how to cook an omelet?”

>Are they disabled in any way?

>“If we came to your house for dinner, what would you prepare for us?”

>Are you allergic to any type of food?

>“My wife and I are going on vacation, where would you recommend?”

>Are you going together?

I actually quite liked these answers, and I would think positively of a candidate who asked them (assuming I would ask the questions in the first place, which is unlikely).

While "Define this that and the other ad nauseum" is probably overly pedantic, the above do illustrate an ability and propensity both for analysis as well as even perhaps empathy - both, IMO, meaningful skills when developing a product.

Re: Wacky interview questions

#44

Post by crntaylor »

thinkstoomuch wrote: post #35
crntaylor wrote: post #24

Earlier quoted context omitted.

The minute hand is at 300 degrees and the hour hand is at 354 degrees, so the correct answer is 54 degrees (subject to me not having messed up the arithmetic).

Interesting, I come out to 55 degrees this way: 30 degrees between hours. 10 is at 300 degrees, 11 is 330 degrees. 50 minutes into the hour is 5/6 of 30 or 25. 330+25 == 355.

You're totally right, of course. I originally wrote 55 degrees (using exactly your argument) then looked at an actual clock and edited my post. Overthinking...

Re: Wacky interview questions

#45

Post by columbo »

IvyMike wrote: post #39
MattRogish wrote: post #14

These aren't just wacky, they are stupid. "How many ping-pong balls can fit in a VW bus" is just about the worst question I've ever gotten. Little or no relation to software development. Here's what we do. Interested in feedback, please! Via the phone: * A few background questions (why are you looking for a job, what sounds interesting about what we are doing) (20-30 minutes) * A bunch of topgrading questions http://…

> "How many ping-pong balls can fit in a VW bus" is just about the worst question I've ever gotten. The point of questions like this is "Does this guy have any common sense?" Some of my least favorite hires were people who were whip-sharp at the details of their chosen programming language, but then when hired, would go off and do crazy and impractical stuff with it. Whether or not the question accomplishes a good ev…

> The point of questions like this is "Does this guy have any common sense?"

GROOOOOAAAAN

Maybe twenty years ago, and maybe if you were the individual to think up the question.

Honestly I'm so goddamned bored with these unoriginal blither-blather questions I consider them a strike against the interviewer and the company.

Re: Wacky interview questions

#46

Post by crntaylor »

dalke wrote: post #40
crntaylor wrote: post #19

Earlier quoted context omitted.

I once interviewed at a place that had an interesting spin. They gave me three fermi questions, which I had 5 minutes total to estimate: 1. Mass of the earth in kg 2. US GDP 3. Number of carriages on the London Underground I then had to give a 95% confidence interval for each one (i.e. an interval that I was 95% sure the true answer lay in) and then asked, for each estimate, which bet I wanted to take: 1. Bet that th…

Which would be more impressive: that I long ago memorized that the Earth's mass is about ~5.98E24 kg or that I could estimate it knowing Kepler's third law (T-squared = C * R-cubed) and orbital information about the Moon(28d@250,000miles), Earth (365d@1AU), and Mercury (88d@0.4AU), where 1AU=93million miles. Or that I could cross-check it by knowing the circumference of 25,000 miles to get the approximate volume, and…

Almost all of the interesting stuff comes after you've made your estimates (although the process of getting to the estimates is not completely uninformative).

If the candidate performs well on this question, then they have shown:

1. They have the ability to reason about problems in a potentially new domain.

2. They have the ability to pare down a problem to what is important and what can be neglected.

3. They can make good order-of-magnitude estimates (very important for an equities trader).

4. They are aware of the typical size of their errors, or can estimate them.

5. The are aware of the typical sources of error.

6. They understand the notion of a confidence interval and can apply it to real-world situations.

7. They can reason about bets with different characteristics (e.g. different expected value, different skew characteristics) and choose a good portfolio of bets.

I think that knowing how GDP is calculated is useful information for someone working in finance. Especially someone who is going to have to trade through economic announcements. Would you hire a trader who didn't follow economic news?

PS re "shows you've visited London" - the interview was in London. I assume if it had been in New York, they would have asked about the New York metro.

Re: Wacky interview questions

#47

Post by IvyMike »

columbo wrote: post #45
IvyMike wrote: post #39

Earlier quoted context omitted.

> "How many ping-pong balls can fit in a VW bus" is just about the worst question I've ever gotten. The point of questions like this is "Does this guy have any common sense?" Some of my least favorite hires were people who were whip-sharp at the details of their chosen programming language, but then when hired, would go off and do crazy and impractical stuff with it. Whether or not the question accomplishes a good ev…

> The point of questions like this is "Does this guy have any common sense?" GROOOOOAAAAN Maybe twenty years ago, and maybe if you were the individual to think up the question. Honestly I'm so goddamned bored with these unoriginal blither-blather questions I consider them a strike against the interviewer and the company.

I actually have never asked an estimation question, but I understand the motivation for asking this kind of question.

I'm curious--what do you ask in interviews to get at a candidate's common sense? It's not very easy to do.

Or do you think you don't need to assess common sense at all? Maybe it's not, but like I said, a lot of the hires I later regretted came down to something like that.

Re: Wacky interview questions

#48

Post by orangethirty »

Domenic_S wrote: post #42
orangethirty wrote: post #34

Earlier quoted context omitted.

Of course it matters. The ask to make the calculation when its 11:50. I need to know if I'm free to be able to go and calculate it at exactly 11:50. I would not want to do the calculation at 11:49 or 11:51, because then I could be missing another calculation appointment. Using when implies that I do the calculation at the exact point in space-time, and not calculate the angle of the clock pointers at the moment the c…

You must be a blast at parties.

Define party. Political party? Social Gathering?

Re: Wacky interview questions

#49

Post by orangethirty »

doktrin wrote: post #43
orangethirty wrote: post #32

M$: 1.Define diaper. As in adult, children, paper, cloth, etc. 2.So it doesnt fall down the hole it is covering. Amazon: Depends on how much PHP I have to write. Google: Define cow. Does it only apply to the common animal or does it also apply to the slang used to refer to overweight people? Zillow: Define success. Expedia: Which language version for the T9 keypad? In what language do the words have to be found? “If…

>“Estimate how many windows are in New York.” >Are we refering to regular windows or computing devices running the operating system Windows? Plus, define Window. Is it an opening in a wall? Does it need to have a glass plane? >“How would you direct someone else on how to cook an omelet?” >Are they disabled in any way? >“If we came to your house for dinner, what would you prepare for us?” >Are you allergic to any type…

Its all in good humor, but it shows that I've been involved in product development/marketing for a while. I'm particularly proud of the "my wife and I are going on vacation" answer, because I was actually asked that one in real life by a friend. I replied the same way. His response was to laugh histerically. :)

Re: Wacky interview questions

#50

Post by orangethirty »

IvyMike wrote: post #36
orangethirty wrote: post #32

M$: 1.Define diaper. As in adult, children, paper, cloth, etc. 2.So it doesnt fall down the hole it is covering. Amazon: Depends on how much PHP I have to write. Google: Define cow. Does it only apply to the common animal or does it also apply to the slang used to refer to overweight people? Zillow: Define success. Expedia: Which language version for the T9 keypad? In what language do the words have to be found? “If…

"Candidate is contrarian for the sake of being contrarian, and avoided answering all questions." I know you're joking, and there is value to getting the interviewer to clarify the question and confirm assumptions. But some of your responses ("define be") are nitpicky to the point of "this guy wouldn't be any fun to work with".

"this guy wouldn't be any fun to work with".

But I always show up for the weekly lets sing happy birthday to those who had their birthday this week. And sometimes I'm the one who brings the cake. That's the definition of fun[1].

[1] In corporate America.

Post reply on HN