In my experience, about one in five (20%) people I get to interview can solve basic programming problems on a whiteboard (in their language of choice). It's really depressing.
Ask HN: What % of your job interviewees pass FizzBuzz type questions?
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Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#22About 80%. Perhaps we're more vigorous with resume screening. Over the last 4 years of interviewing, I've become very good at resume screening.
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#23The last time I was a part of this activity in a company (1997-8), using similarly rigorous pre-screening, we had about the same results, only 50% of the people we interviewed could program their way out of an (EDIT) wet paper bag.
How would I go about programming my way out of a paper bag? It creates the weirdest ideas and images in my mind.
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#24I'm curious what candidates are getting stuck on. Is it the testing for divisibility that's tripping them up?
Mostly they just don't know how to start. They can't break down the problem into subproblems. Once a candidate managed to break down the problem to subproblems, they can always do the rest easily (solving the subproblems, composing the solutions to solve the main problem).
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#25I've actually asked this question as a gentle warm up for people, and we achieve around a 90% success rate.
On average it takes people around 5 minutes to do.
We have people do it on a whiteboard to get them standing up and moving.
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#26Earlier quoted context omitted.
Ok fair enough, but I'm still curious where the sticking point is. Can they at least code the loop? I'm wondering if it's just that peoples' math skills are typical pretty rusty and if using another set of conditions would give you better results. Edit: For example, iterate through this string every time you hit an 's' print fizz etc...
For some reason this is the most common mistake I see from students: for i in range(0,n): if i % 3 == 0: print 'fizz' elif i % 5 == 0: print 'buzz' elif (i % 3 == 0) and (i % 5 == 0): print 'fizzbuzz' else print i It's not so much arithmetic that's the problem but reasoning about overlapping boolean conditions.
Hmmm.. I see. Is this done on a whiteboard? If you let them
use an editor and run it and they fixed it right away
would that be acceptable?
I wonder if people are getting such bad results on this because it's always the first question they ask and the candidate isn't comfortable yet.
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#274 candidates, 2 passed FizzBuzz. Oddly, the two that failed had a Masters in CS (albeit no BS in CS).
Of those that passed: one had Masters in Library Science looking to change careers. The other was a fresh out of college CS major from Illinois State.
Next batch, I think we'll add another trivial question: count the number of vowels (a, e, i, o, u) in a string.
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#28Earlier quoted context omitted.
Ok fair enough, but I'm still curious where the sticking point is. Can they at least code the loop? I'm wondering if it's just that peoples' math skills are typical pretty rusty and if using another set of conditions would give you better results. Edit: For example, iterate through this string every time you hit an 's' print fizz etc...
For some reason this is the most common mistake I see from students: for i in range(0,n): if i % 3 == 0: print 'fizz' elif i % 5 == 0: print 'buzz' elif (i % 3 == 0) and (i % 5 == 0): print 'fizzbuzz' else print i It's not so much arithmetic that's the problem but reasoning about overlapping boolean conditions.
Agreed. When we see people trip up it's often becaues of this.
I think the problem is the old adage about not being able to to see the forest for the trees.
They break it down to the simple components and write those fairly easily but the forget about big picture of all 3 conditions working together.
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#29Just curious if you expect perfect code on a sheet of paper or give them an IDE and say go for it. As I remember fizzbuzz (print numbers 1 thru x, then fizz if divisible by 3, buzz if divisible by 5, fizzbuzz if divisible by both) I did it in a text editor in under a minute. Got two errors because I did it without thinking, fixed it, and had a working solution in 90 seconds. It's taking me longer to write this respon…
Back in the days when I did this (1990s) we did the C/C++ reverse a linked list and compute the factorial of a number. And, yeah, people made mistakes on a dry erase board under interview pressure, but it was very clear who has a clue vs. who couldn't program their way out of a wet paper bag.
These sorts of tests are low pass filters, they're not designed to find good or great programmers, just confirm that the person can program at all (as we define it). Since most people who call themselves programmers really aren't, they're highly useful. Anyone who's looking for perfection of this nature in an interview and who fails a candidate for lacking that is doing the latter a favor by not hiring them.
Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?
#30I wish we would run at least some kind of sample problem before hiring people. sigh
Indeed; if you interview at a company that doesn't to this sort of thing if you have any choice you're well advised to avoid them. There's simply going to be little joy working with people who can't program and can either stick around or who have to get fired. And things can get ugly for those who do have a clue, from envy to having to do others work to avoid project or company failure and losing your job.