
Dark Motives and Elective Use of Brainteaser Interview Questions - 33degrees
https://onlinelibrary.wiley.com/doi/full/10.1111/apps.12163
======
jfasi
As someone who does both a lot of interviewing (at Google) and gives a lot of
advice on interviewing to people just starting out, this rhymes with my
intuition about why some people get into interviews: even without the use of
brainteasers (which, for the record, are not used at Google), the interview
process is _hard_. People rarely come out of it without at least a twinge of
frustration of humiliation. I'm not immune to this, I got hired at Google
despite having a few interviews where I thought "God damn that was horrible,"
and I didn't get offers at places I know I was good enough to work at because
I wasn't performing at my best for whatever reason and nuked the interviews.

I have a pet theory that when people interview they bring this buried
frustration into the room with them and use the interviewing process to play
the part of the people they feel humiliated them. It's conceivable that people
with latent meanness, or as this abstract calls it tendencies for "narcissism
and sadism" who aren't aware enough of their biases to try to counteract them,
will use these sorts of questions to make themselves feel better.

Also, and this is probably more specific, there's a bit of a mythos around
companies like Google and friends that have tough interviews and high
standards: they hire the best people, they're doing the best work, they're the
smartest, etc. I can tell you from experience, that mythos doesn't hold up
once you're doing you day to day job. I've seen people with stunning
credentials doing what most would consider exciting work become genuinely
_bored_. Perhaps for some of them interviewing is a way of reminding
themselves of how desirable and high status their workplace is, to the
detriment of the poor candidate.

And of course, as a disclaimer, this isn't even anecdote, these are my own
personal musings on psychology. Don't confuse this with insight into the
Google hiring process.

~~~
pinewurst
It's like military academy (or fraternity) hazing. You've been abused,
therefore you want to pass the load of that abuse on. Maybe you delude
yourself into calling it "tradition" or "high standards" or maybe you're just
honest and enjoy the sadism of it all.

~~~
wolfgke
> It's like military academy (or fraternity) hazing. You've been abused,
> therefore you want to pass the load of that abuse on.

I really cannot imagine why people have this behavior. I was often treated
unfairly in life, so I try to architect systems that attempt to avoid my
perceived unfairness so that the next generation does not have to suffer
similarly (ideally in way for which correctness can be shown in a
mathematically rigid way).

~~~
throwawaymath
I think the answer is that most people are not like that, and the ones that
are don't think about it from that perspective or that explicitly. All
disagreeable human behavior is easy to point out and criticize in its most
straightforward and uncharitable representation.

~~~
stcredzero
_I think the answer is that most people are not like that, and the ones that
are don 't think about it from that perspective or that explicitly._

That, in a nutshell, is why a lot of abnormal psychology is so very sticky.
It's even worse than that, however. It's more that most people are just a tiny
bit "like that," and no one thinks about it from that perspective.

------
8_hours_ago
I recently interviewed at Apple and one interviewer caused me to decide to
never work there. I was put into a conference room and had 8 people over 6
hours come in and interview me one after another. Each person asked me about
my background and then jumped into a whiteboard coding problem. Most of the
interviewers were understanding of the fact that writing code on a whiteboard
is nothing like writing code on a computer, and were helpful in pointing out
simple mistakes that a compiler would have caught.

While writing code for the last interviewer I had to do some simple division.
I came up with the wrong answer and told the interviewer that I wasn't sure if
that was correct, and to let me know if it was incorrect. He blankly stared at
me and said he wouldn't help me. Usually I would be able to do the division in
my head, but after 6 hours of constant interviewing my brain was starting to
turn into mush. I went on and finished the solution and he said that there was
an issue but wouldn't tell me where. I asked if it was an issue with the
division and he said yes. He still wouldn't tell me the answer, so I
floundered for a bit while trying to remember how to do long division.

At one point I turned to him and said "I'm sorry this is taking me so long,
it's been a very long day" and he replied "sometimes you will have to fix your
code on the spot". It seemed like he was trying to see if I would crack under
the pressure. Eventually I came up with the correct answer and was able to
finish the problem, but it completely drained me.

I decided then that I never wanted to work with that person, or with other
people like them.

Some jobs require performance under pressure, but programming is not one of
them. The only thing that the interviewer was evaluating was my ability to do
math problems in my head after being interviewed for 6 hours. Don't they have
calculators at Apple? Or phones, perhaps?

~~~
corey_moncure
So you met 8 people, and one of them was a jerk? I'd say that's a pretty
acceptable jerk coefficient for a workplace. I've been in places north of 0.5.

~~~
geofft
The right number is zero and a UBI until they figure out how to stop being
jerks. (My primary personal reason for supporting a UBI is I want to be able
to say "No rational employer should employ you" without that implying "so you
should be homeless and starve.")

But short of that, the right number is zero _on the interview circuit._ You
can employ jerks if you have to, but don't put them in more positions where
they have to interact with others than necessary. Give them the legacy
products where you can't staff a team of more than one qualified person
anyway. Give them an office. And keep the door closed.

Remember that a jerk is basically a 0.1x developer - an employee who causes
other employees to lose productivity by spending time working around the
jerkiness, taking a morale hit, etc. Even a remarkably productive jerk at best
only compensates for their negative effect on people they work with, and most
jerks are not consistently remarkably productive.
[https://medium.freecodecamp.org/we-fired-our-top-talent-
best...](https://medium.freecodecamp.org/we-fired-our-top-talent-best-
decision-we-ever-made-4c0a99728fde) is a good example of a company learning
that lesson a little too late. A company that signals that they trust their
jerks enough to make hiring decisions and to represent the company's culture
to potential new hires is a company that signals they're actively cool with
jerks (or incapable of noticing, which has the same effect).

If a jerk makes a good employee unhappy and they leave, the jerk is a net
negative. And if you keep employing the jerks, you'll find yourself with a 0.5
jerk coefficient on your hands very quickly.

~~~
Bahamut
Just hiding how many jerks a company has until after the interview process is
complete is not effectively any better - it could even be worse for people, as
they could have had signal to avoid the jerk. The absence of evidence of some
behavior or signal is not equivalent to it not being present at all.

In my experience, most companies have jerks - I’m not convinced it’s even
avoidable reliably, as people come from many walks of life, and sometimes the
walks form people to be jerks.

I work at Apple, where I’d say that jerks are a very low number of people I’ve
interacted with (maybe a couple hundred employees so far) - I’ve seldom seen a
company beforehand with less jerks percentage-wise, much less have processes
that help with descalating arguments & deal with them quickly.

------
Syzygies
I interviewed a full day at a mathematical hedge fund. Not exactly
brainteasers, rather a barrage of good, solid math and stats questions. Such a
day is exhilarating (like skiing the Olympics) but truly exhausting, and only
partially related to whether one gets an offer.

My advice to anyone doing this would be to give up the last 10% of performance
in order to focus some on contextual awareness. These puzzles are a form of
pre-surgical anesthesia, before they ask the real questions. You need the
spare cycles at the end of a long day to imagine what casual conversation
might really be exploring, how other applicants might misread the subtext,
what mistakes in previous hiring they're trying not to repeat. One could be a
genius trained seal, by buying into the brainteaser game, and miss the broader
question of how you will fit into their firm. One who sees broader contexts
ends up running places; don't make it clear that's not you.

~~~
throwawaymath
Would you say the questions that fund asked you are relevant to the work you
do (or would be doing) there? I think that's the core criticism most people
levy against the "high tech" interview questions.

~~~
segmondy
People that don't get the offer tend to complain about such things. They are
asking questions to measure how you think, to measure your potential, to see
how you handle stress. If you are stressing over an interview, what will you
do when you lose $1 million in 10 seconds?

~~~
kanelbullar
_If you are stressing over an interview, what will you do when you lose $1
million in 10 seconds?_

Beats me - but the "skills" demonstrated in the interview process you're
defending -- "suck up; just keep going online until you memorize enough canned
answers to most of these dang questions; suck up, suck up, suck up" \--
certainly aren't going to help.

If anything, they're basically orthogonal to the set of competencies needed to
deal with that kind of a situation.

~~~
stcredzero
_Beats me - but the "skills" demonstrated in the interview process you're
defending -- "suck up; just keep going online until you memorize enough canned
answers to most of these dang questions; suck up, suck up, suck up" \--
certainly aren't going to help._

Right. People who don't think of Comp Sci knowledge as a set of substantive
first principles, just as meaningless tokens they need to memorize and
regurgitate to get the job -- those are precisely the people who _should_ be
weeded out. Each one of those questions is not merely a chance to "collect" an
arbitrary thing. It's also an opportunity to practice applying basic knowledge
and techniques.

 _If anything, they 're basically orthogonal to the set of competencies needed
to deal with that kind of a situation._

You may well need to spot a deadlock or a race condition in code. You may well
need to spot code that is inefficient by construction, in precisely that kind
of situation.

~~~
kanelbullar
_People who don 't think of Comp Sci knowledge as a set of substantive first
principles, just as meaningless tokens they need to memorize and regurgitate
to get the job -- those are precisely the people who should be weeded out._

And yet - those are the people who are not weeded out, but _selected for_ by
the default interview process.

~~~
stcredzero
Certainly, there are lots of problems with interviews.

That said, the interview should be designed to specifically weed out the ones
who hope to pass by regurgitation. The answer can't be just a pattern match
for a particular algorithm. The emphasis shouldn't be on dazzling recall of
something obscure. The purpose should be to look for actual experience
implementing something.

------
spython
This reminds me of Jewish Problems[0], designed to "prevent Jews and other
undesirables from getting a passing grade" at the entrance exams to the math
department of Moscow State University.

[0] [https://arxiv.org/abs/1110.1556](https://arxiv.org/abs/1110.1556)

~~~
golergka
Wow, I never knew they actually published a paper on it. Coming from a Moscow
math school that traditionally had a lot of jewish students, most of whom went
on to MSU to study math, I remember studying these exact problems - although
in my time, this filter was supposed to long been gone.

------
riyadparvez
My issue is more with tricky algorithmic questions. I faced these tricky
interview questions, where you either have to know the trick beforehand or
there is NO way you can come up with a solution in an interview. I never
understand the point of these questions. Because these esoteric hypothetical
questions will almost never come up in real-life. They don't test someone's
skills, because these problems don't follow any standard algorithmic problem
solving procedure. They mostly test whether you know the trick or not, which
is not a valid metric of skills.

One famous example of this type of questions is to find loop in a singly
connected linked list. Now almost everyone knows the trick. And thanks to
that, interviewers have stopped asking questions like that.

~~~
jf-
Most algorithms questions only prove one thing: whether a candidate has
brushed up on algorithms beforehand. That has some usefulness, being a proxy
measure for conscientiousness, but offers little beyond that. Maybe that
they’re able to follow the reasoning, but it could just as easily be learned
by rote and parroted back. The fact is that no one comes up with a from-
scratch efficient algorithm for doing anything in 5 minutes, the candidate
either knows it going in, or they’re screwed.

~~~
bordercases
The test lost its validity over time, but how many people care about their
craft enough to know how to write software without using a library, and be
willing to reason about it from first principles? Or with systematic method?
They would be capable of doing original work. The rest I'd give CRUD tasks to.

~~~
jf-
An algorithms question proves today what it proved 15 years ago: that the
candidate learned the algorithm. It does not and never did prove that the
candidate spontaneously generated the solution in the interview. In other
words, it isn’t an intelligence test. It isn’t even a programming aptitude
test, but it is a conscientiousness test because the candidate went to the
trouble of learning many algorithms successfully. That does count for
something, but not necessarily what the interviewers expect.

If you want to test for programming aptitude, give the candidate a realistic
but difficult real world problem and let them solve it in an IDE.

------
manish_gill
I took an interview today and was asked a simple problem which I immediately
answered with linear time complexity. The interviewer then went on to say "no
I'm looking for a specific answer which involves a trick".

Literally said those words.

Eventually figured it out but I came away with a bad impression of the
company. Not the kind of stuff I judge people on.

~~~
dbt00
“Are most of your day to day problems solved by rote memorization of
esoterica?”

------
nimbius
I dont work in tech, im an engine mechanic by trade, but im fascinated to know
why/how often this happens in a tech interview? Do programmers/sys admins
really endure this kind of aggravation in their interviews?

The hardest question I've ever asked one of my shop mechanics during an
interview was how does Exhaust Gas Recirculation (EGR) in a Diesel engine
affect thermal efficiency, smoke output and emissions of the engine...and that
was for a full-time diesel tech at our cross town location.

id imagine if i ever started throwing out manhole cover questions or
underwater airplane bullshit, i'd catch some hands before I managed to hire
anyone.

~~~
pnw_hazor
Think of the type of person that would suffer through this type of
indignation. And, the type of person the gleefully puts people through this
kind of hazing.

Sounds like perfect formula for building toxic workplaces full of people with
personality disorders.

~~~
pinewurst
That's why I'm not a software developer any more, even though I greatly enjoy
the creative aspects of the work.

------
spitfire
Hunter and Schmidt did a meta-study of 85 (now 100, with the follow up) years
of research on hiring criteria. [1] There are three attributes you need to
select for to identify performing employees in intellectual fields.

    
    
        - General mental ability (Are they generally smart)
        Use WAIS or if there are artifacts of GMA(Complex work they've done themselves) available use them as proxies. 
        Using IQ is effectively illegal[2] in the US, so you'll have to find a test that acts as a good proxy.
    
    
        - Work sample test. NOT HAZING! As close as possible to the actual work they'd be doing. Try to make it apples-to-apples comparison across candidates. Also, try and make accomidations for candidates not knowing your company shibboleth/tools/infra.
    
    
        - Integrity. The first two won't matter if you hire dishonest people or politicians. There are existing tests available for this, you can purchase for < $50 per use.
    

This alone will get you > 65% hit rate [1], and can be done inside of three
hours. There's no need for day long (or multi-day) gladiator style gauntlets.
Apply this process to EVERYONE, including that elite cool kid from the "right"
school/company. You don't want to exclude part of your sample population!

[1]
[http://mavweb.mnsu.edu/howard/Schmidt%20and%20Hunter%201998%...](http://mavweb.mnsu.edu/howard/Schmidt%20and%20Hunter%201998%..).

[2] Technically IQ tests are not "illegal", but the bar courts have decided
companies have to climb is so high it effectively means they are. There is
existing case law directly covering IQ tests in hiring. You should speak with
your lawyer before you decide to try IQ tests. [3] 2016 update of Hunter
Schmidt:
[https://home.ubalt.edu/tmitch/645/articles/2016-100%20Yrs%20...](https://home.ubalt.edu/tmitch/645/articles/2016-100%20Yrs%20Working%20Paper%20for%20Research%20Gate%2010-17.pdf)

~~~
pmiller2
What sort of meaningful work sample test can you do in 3 hours?

~~~
Izkata
A year or so ago, one of our devs got some questions on our test replaced with
things of the type the maintenance team occasionally gets asked, instead of
making it solely about development and bugfixing, though twisted a bit to be
feasible in an interview test (for example, the source data they'd work on was
something like a 3 MB JSON file instead of a database).

Questions involved figuring out how to manipulate that data, and since not a
single one could be done solely with a library call it said a lot about their
ability to think through a problem, as well as their knowledge of things like
data structures and efficiency. The latter questions even built off of the
earlier ones, as if the stakeholder came back with more questions.

With a reasonable knowledge of the language you were using, those questions
would only take around 15-30 minutes total, and each answer (as long as you
did correctly build on the previous ones) was only ~5-10 lines of code.

------
rrggrr
The single most effective interview question I ask: "What do you want to do?".
I drill down on that to a granulator level as I try to make sure the tasks,
duties and overall position matches what the candidate really wants for
themselves. Its followed-up with a "How would you do it?", again persisting in
the discussion (not interrogation) until we both are comfortable with the
sensibility and symmetry of the answers.

~~~
eip
If you think anyone 'really' wants to build your shitty CRUD app then you are
deluding yourself.

Do you 'really' love your job? Would you do it for free?

~~~
rrggrr
Ouch. So, I'm not in the software business, but either way the point of my Q&A
is measure the distance between what an employee wants to during the day
versus what probably needs to be done to accomplish the desired result. When
the gap is big the hire/job never works out.

~~~
eip
> what an employee wants

What I 'want' to do during the day is be a sunscreen boy for the Reef bikini
team.

What I am willing to tolerate in exchange for money is considerably wider
ranging.

No one 'wants' to be trapped in some corporate soul sucking nightmare for five
days a week.

------
rossdavidh
So, there's a hidden value to these sorts of questions, but it is useful to
the interviewee, not the interviewer. If they use lots of these questions, you
probably don't want to work there, or at least not for the person who's asking
those questions.

~~~
welcome_dragon
I disagree, as long as getting the right answer isn't important. I flat out
tell people I don't care if they get the right answer, that I just want to
hear their thought process.

Such questions used in this way are extremely valuable.

~~~
athenot
I do the same thing. It's how the _thought process_ works that's interesting,
not the result. There is no problem or teaser whose answer is both short
enough to be devised during an interview AND is representative of how a
candidate would perform in real projects. Our field deals with complex systems
in many dimensions.

Instead, looking for how a candidate approaches a problem, do they just go for
the obvious solutions, how creative will they go, any experience they can draw
on, how well they overcome unknowns, etc.

~~~
gaius
_It 's how the thought process works that's interesting, not the result._

I wonder how many interviewers have the necessary background in clinical
psychiatry to analyze a candidate's thought process, or if that's just more
handwaving away hazing.

------
framebit
I had one of these brainteaser questions in an interview once, and I liked my
mathematician friend’s answer to it the best.

Q: Given infinite setup time and infinite money, how would you fill the inside
of a 747 with ping pong balls as quickly as possible?

A: Define the inside of the plane as the exterior. Now, by definition, all
ping pong balls are inside the plane. QED.

~~~
bfrydl
My answer:

I use my infinite resources to become benevolent dictator of Earth.

With my endless wealth I prevent climate change, provide the basic needs of
every person on the planet, educate the world, and set up a global system of
sustainable reproduction. I have infinite resources so I assume it's not
eugenics or something dystopian, but more a collective human understanding of
responsibility. Finally, with our future ensured, I dedicate as many of the
world's top minds as possible to preserving my own life at any cost.

Once I have achieved immortality, likely by transplanting my mind into a robot
body that can be updated over time so I remain the most advanced being on the
planet, I steer the course of human history far into the future. All human
suffering is ended. We all work as one to better ourselves. We spend decades,
centuries, millennia improving not only our society, but our technology for
inserting ping pong balls into 747s.

Under my kind leadership as an immortal god-king of increasingly sophisticated
artificial intelligence, humanity becomes the dominant species in a
surprisingly crowded universe. With each new species we meet, we find new
allies in our advancement. Entire galaxies unite under my rule and never-
ending resources, each furthering my transcendence of life and the speed at
which we can put small plastic balls into extremely archaic public
transportation.

Finally, at the far end of time, when there is nothing left to learn, no
secret of the universe left unknown to me—I am now a single bio-mechanical
entity composed of all intelligent life in existence—my setup is complete.
Using technology so advanced that it cannot be described by words we have so
far invented, technology so unimaginable it exceeds the power we ascribe to
magic, I fill the plane. It is instantaneous. There is no time during which
the plane is being filled. There is only before and after it was filled.

The creator of the universe descends on its final moments. The being sees the
plane. It weeps for the beauty its children have created.

~~~
ItsMe000001
> when there is nothing left to learn,

I only logged in to comment on this :-)

This won't happen, ever. That's because new things to learn are being created
all the time!

For example, when there was no horse there was no horse riding. When there was
no computer there was no programming. Just two infinitesimal examples to
demonstrate what I mean.

Knowledge of "basics of the universe" such as quantum theory are of no use to
a "higher order" being such as ourselves when almost all of us apart from a
few physicists work on much higher planes. The matter and energy of the
universe is constantly being rearranged to create more and more and higher
higher order problems, you will _never_ run out of new ones. First we create
the problem, than we solve it, creating new ones (and the whole universe does
it too, and biological stuff especially) :-)

~~~
bfrydl
Who am I going to believe, a human in 2018, or a transcendent being composed
of the unity of life in all its forms across the entire universe who has
dedicated an unfathomable amount of time to uncovering every mystery related
to ping pong balls and 747s?

------
bitL
So, FAANG is full of carefully selected sadistic narcissists thinking they can
"save the world"? Sounds like fun :-D

Seriously, I thought brain teasers are a funny game and an intellectual
version of "xyz" measuring contest, showcasing equivalent of "street smarts"
in higher level brain functionality and a signal about how much boring one
would be for an interviewer to work with. Now this secret dark-triad dimension
completely bypassed my attention as I actually enjoyed them a lot.

------
srinivgp
The "brainteaser" question type in the survey is just another type of
question. If you've seen/practiced Fermi estimates, it's pretty rote. If
you've never seen/practiced Fermi estimates, it will sound like a horrible
trick question. I wonder how well it would work to begin with "are you
comfortable with Fermi estimates?". If so, go ahead and ask. If not, _teach_,
do a couple together, then have the candidate do one on their own. The
technique isn't hard, it's just surprising that it can work and work pretty
well if you haven't already been exposed.

~~~
hfdgiutdryg
"Fermi estimate" questions are stupid most of the time. Why? Because they
leave out the _educated_ part of educated guess.

The idea is that inaccuracies in a series of educated guesses would tend to
even out (though they're just as likely to compound). There is no such
tendency in blind guesses, which is what most of these questions require.

------
ElysianEagle
I realize that the study was specifically talking about brainteasers, but I
wonder if irrelevant algorithm questions have a similar motivation? I was once
asked at an interview at a FAANG company to come up with an algo for finding
the longest palindromic subsequence (!). At another I was asked to get all
partitions of an integer
([https://www.whitman.edu/mathematics/cgt_online/book/section0...](https://www.whitman.edu/mathematics/cgt_online/book/section03.03.html)).

I'm pretty certain I'd never be working on problems of that nature as part of
the role.

~~~
repsilat
> _an algo for finding the longest palindromic subsequence (!)_

Not irrelevant to my professional career, to be honest. There have been a few
situations where being able to see a tricky, unfamiliar problem and after some
thought say, "oh, we can use a DP algo for that" has saved a large amount of
future headache.

Only a small fraction of people on the team need to have that skill (more in
some teams than others, too) so I don't think it's a great thing to test for
(much less require), but it's actually a pretty valuable skill in my
experience.

------
anonytrary
A Fermi problem is not a brain teaser in the colloquial sense, it's more of an
approximation game. If you looked up an answer a week ago and memorized it,
then regurgitated it, you'd still get the question "wrong". No one expects you
to come up with the right number of windows, they expect you to get somewhere
plausible from scratch.

Asking someone how many windows are in NYC is not fundamentally different than
asking someone how many blades of grass are on a soccer field. You can know
almost nothing and still arrive at the correct order of magnitude -- all it
tests is someone's ability to do napkin math and break open-ended problems
into manageable parts.

Is this the right thing to test? That depends on what you're hiring someone
for.

------
ectospheno
When interviewing I would often ask one (and only one) question of this type.
The rest of the interview was your standard set of questions to see what type
of person you were sitting across from.

The one "brainteaser" question was "Estimate how fast human hair grows in
miles per hour. Order of magnitude is fine."

I just wanted to see that they not only knew how to estimate something but
that they understood this particular estimation wasn't important given the job
they were interviewing for and could thus be answered quickly rather than
accurately.

The one person who answered immediately was off by 3 orders of magnitude but
he was the best hire we had. He could spot BS a mile away.

------
EngineerBetter
We ask people to pair-program with an interviewer on a realistic task. No
tricks, no brainteasers. We just get to see how people do the job we want them
to do.

~~~
biztos
Is pair-programming actually used in your company?

Just curious, as I do something similar but solely to see how the person
writes code. Folks are free to pair-program or not once hired.

I've found almost everyone needs help on some simple part of the task, and how
they respond to the help is pretty useful information.

~~~
bitwize
I've interviewed at places with a pair programming part of the interview, that
didn't use pairing during actual development.

It is an enormous help toward glimpsing the mind of the programmer _as they
program_.

------
codingdave
Interviewing others can certainly expose your own faults. In our last round of
interviews, I certainly could have done better by our candidates. I learned,
and will do better next time.

But judging a company based on their questions may be expecting too much.
Nobody is perfect, and if you expect perfection from someone who will end up
being a member of your team, you might be setting everyone up for
disappointment. Or you might be walking away from a good team or product just
because they are not good at interviewing.

Instead, if they ask questions that imply cultural problems or personality
conflicts, ask about it. Find out if they are just bad interviewers, or if
they do have deeper problems. Because bad interviewers are not always a bad
sign -- it could mean they don't have to do it often. It could also mean they
are trying to expand the skills of people new to interviewing by giving them
opportunities to do something new. Also, companies who have mastered the
interview process means they do it often, which could be a sign of high
turnover.

In short, it is good to notice problems, ask about them, then think through
all the implications of the answers before making decisions.

------
logifail
I was asked a series of brainteaser interviews at a university interview.

It was immediately clear that the purpose of the questions wasn't really to
see if I knew the answers, but to see how I responded when asked about
something I didn't (immediately) know the answer to.

Isn't this a perfectly legitimate way to try to see how a candidate might deal
with solving problems they don't know the answers to?

Ironically one of the interviewers (a somewhat crusty old astrophysics
professor) later became my physics tutor, and continued to ask us brainteaser
questions during tutorial sessions.

For instance, I dimly recall us being asked to "estimate the change in the
length of the Earth's day if all the cars in the UK were to drive on the
right-hand side of the road instead of on the left"...

------
mfonda
Being able to approximately estimate numbers is an excellent skill for
software developers to have. Imagine you're running some operation that
affects N things or has N results. After seeing the results, it's very helpful
to ask yourself "Does N roughly match what my intuition/estimate told me it
would be?" If your estimate is off by at least an order of magnitude, it's a
hint there could be a bug in your solution and that it warrants a closer look.

I don't ask brainteaser type questions, but I can see their appeal given the
value of estimates. I also don't see why they're so universally hated. Is
doing back-of-the-napkin math something a lot of people struggle with?

------
yters
It'd be interesting to see whether the interview brainteasers translate to job
performance, especially where being able to solve lateral thinking and
analytic problems is important for doing well at the job. That might explain
why such questions are used during the job interview.

~~~
solomatov
They don't according to this article:
[https://www.theatlantic.com/business/archive/2013/06/google-...](https://www.theatlantic.com/business/archive/2013/06/google-
finally-admits-that-its-infamous-brainteasers-were-completely-useless-for-
hiring/277053/)

------
cubano
Maybe the correct stratagy is turn the tables and try to lighten the mood of
the interview if a brainteaser is asked, and sort of shuck "oh one of these
things? (laugh)...ok let's work this out together" and proceed to try to
engage the interviewer with estimating the number of floors in an average
building, the number of windows per story, and the number of buildings, all
the time asking the interviewer what his estimates would be?

Like anything to prevent yourself from locking up and taking the damn thing
too fucking seriously.

The reality is we are all going to interview, they are going to mostly suck,
and you will almost certainly eventually be hired somewhere.

~~~
jpttsn
The interviewer doesn’t need to know the number of windows. They need to know
that you will take things seriously on demand.

~~~
ubernostrum
The candidate doesn't need to know how to estimate the number of windows.

They need to know you're the sort of interviewer who likes to be the organ
grinder while everyone else is the dancing monkey. Many common interview
questions give this away quickly, which is useful.

------
quotemstr
Social science generally doesn't reproduce. Why should anyone pay attention to
this story? It seems like it plays into the aptitude-tests-are-bad narrative,
and I fundamentally disagree with that idea.

------
justfor1comment
To account for some interviewers being sadist in general, may be companies can
implement a per interviewer rejection quota. For example, if you interview 10
candidates at max you can reject 7 candidates. You _have_ to yes to 3
candidates or be removed from the interviewing committee. This will ensure
that just one bitter person is not preventing good candidates from clearing
the interview process.

~~~
ubernostrum
I like this video:

[https://www.youtube.com/watch?v=r8RxkpUvxK0](https://www.youtube.com/watch?v=r8RxkpUvxK0)

The speaker formerly worked at Google, and around 8:55 in the video relates
the story of being on a hiring committee that was known for being tough on
candidates. And a recruiter once forwarded a set of interview packets to them,
and they voted "no hire" on all of them. The recruiter then revealed to the
committee that they'd been given their own packets, slightly anonymized, from
when _they_ were interviewed, and had just voted against hiring themselves.

------
csense
I think this particular question (a so-called Fermi problem) is a perfectly
legitimate interview question. Being able to do "back-of-the-envelope
calculations" is a necessary or helpful skill for many technical and
analytical jobs.

It's not about getting the right answer, it's about the candidate's process to
arrive at the answer.

------
opportune
I guess I’m evil because I would refer working with people who can pass brain
teasers to those who can’t. The problem is that you can “prepare” for brain
teaser questions, so you end up selecting for people who prepare more than
people who are actually smart.

------
jkingsbery
I wonder how the "guess how many dog leashes there are in Kansas" kind of
questions would compare to more job-relevant estimation interview questions -
i.e., would the paper find the same sort of conclusions?

------
ummonk
To me, "Estimate how many windows are in New York" is a much more pleasant
question to answer than "Are you a good listener?" or "Tell me about a time
when you failed"...

~~~
sgustard
When you're done hiring you've surrounded yourself with people who are good at
estimating urban fenestration, but are poor listeners who blame others when
they fail.

~~~
ummonk
I'm not saying that is the best question to ask an interviewee. I'm just
saying it's the nicest of the three for me to be on the receiving end of.

(Although, to be clear, "are you a good listener?" is an absolutely terrible
question.)

------
ec664
[no paywall] Link to full paper: [https://sites01.lsu.edu/faculty/zhanglab/wp-
content/uploads/...](https://sites01.lsu.edu/faculty/zhanglab/wp-
content/uploads/sites/158/2017/05/apps_12163_Rev.pdf)

------
emodendroket
I honestly expected this to be talking about discriminatory use of these
questions, so I'm not sure if I should be relieved to see that's not what it's
about.

------
tw1010
Woah, papers on "dark motives", that sounds interesting. Anyone know of any
other good papers on hidden motives similar to this one?

~~~
arayh
I like this paper on dark patterns: [http://colingray.me/wp-
content/uploads/2018_Grayetal_CHI_Dar...](http://colingray.me/wp-
content/uploads/2018_Grayetal_CHI_DarkPatternsUXDesign.pdf)

------
diN0bot
interesting that “teasers” are viewed as callous and abusive and yet
analytical problem solving is viewed as predictive. fine line.

~~~
frandroid
A brain teaser usually has nothing to do with the work... What would asking
about the shape of manhole covers have to do with OOP?

~~~
darawk
The theory would be that it allows the interviewee to demonstrate abstract
reasoning skills, which are useful in many domains.

~~~
prolepunk
Also the interviewee needs to have exactly the same assumptions about the
world as interviewer (or whoever come up with the brainteaser) and the
knowledge of the same basic facts.

I mean how do you even approach questions like -- how many snowflakes on the
south pole? how many fish in all of the oceans? how much grass is in Mongolia?

~~~
darawk
I think that's the point of the question: to see how you approach it. The
'correct' approach that they'd be looking for is 'Fermi estimation':
[https://en.wikipedia.org/wiki/Fermi_problem](https://en.wikipedia.org/wiki/Fermi_problem)

~~~
ubernostrum
No, the point is to try to rationalize cargo-culting. Fermi did this, and
Fermi was brilliant, so if we require candidates to do this we'll end up
hiring people who are as brilliant as Fermi!

Here's a brainteaser: spot all the flaws in that chain of "reasoning".

~~~
darawk
Um, no. It's not cargo-culting. It's the correct way of estimating things. It
has nothing to do with Fermi having done it. Some things actually have correct
answers. 2 + 2 = 4, is not cargo culting.

~~~
ubernostrum
You just moved the goalposts from looking for "a Fermi estimate" to looking
for a correct answer.

~~~
darawk
Um...no. The goalposts have always been that the purpose of the brainteasers
was to demonstrate reasoning skills. Using Fermi estimation is demonstrating
reasoning skills. It's not like some trick that you have to know, it's not a
formula. It's something any intelligent person would do on their own when
faced with a task of this sort.

------
est
I think it's only fair if interviewee was allowed to ask a counter brainteaser
question.

Let the both sides suffer some kind of stress.

------
m3kw9
For me a brain teaser means the company can’t get to the point and unknowingly
is just beating around the bush.

------
masto
I thought everybody stopped doing this.

------
Nokinside
Brainteasers are good for psychological evaluation. How does one perform under
stress or when they are challenged in social situation.

If the goal is to to find out what somebody can do, state a problem and start
working together to solve it. For example ask them to help you to solve some
problem and guide you trough solving it.

~~~
cjg
Does the job involve high stress and a challenging social situation?

Doesn't sounds like somewhere I want to work.

~~~
Nokinside
People who are mentally strong and competitive love working in that kid of
environment.

You need different recruiting and different 'back office' jobs for fragile
people (60-70 percent of the population - and increasingly young males).

------
ccvannorman
I have a totally different sentiment to asking and receiving these wuestions.
To me it's playful and fun and can establish how somone thinks and
communicates. Asking questions like these I might do with my friends just for
fun

------
inetknght
How do I view the PDF with my javascript-disabled browser?

~~~
teraflop
According to the sidebar, you have to pay $38 to download the PDF.

~~~
jimmies
Or you can `/s/doi.org/sci-hub.tw/` the doi URL. ;-)

