[patrickyeon]

Some commenters, and possibly the author, want this advice to extend to job interviews, but the reason an interviewer is pushing you to answer a question isn't that they want you to be right or wrong. A good interviewer wants to get a look into how you think and how you approach a problem.

An even better interviewer will make that clear, by telling you "there's no trick here", "I don't know the answer myself, let's see what we can figure out", or "there's no one right answer, I just want to know what you can see here". A trick I've employed a fair bit lately to get a reserved interviewee to start working with a question is "What is the worst solution we could provide to attack this problem?" I'll even possibly go as far as offering my own horrible solution, and asking them where we fo to improve on this.

And I do mean worst. I haven't met a candidate yet who can't at least throw out ideas on how to improve my horrible solutions, and at that point the ball is rolling.

[RokStdy]

Asking somebody for the worst possible solution seems like a really clever ice-breaker. I'm stealing that technique! Thanks patrickyeon!

I interviewed some folks a while ago for a simple desktop support position and I had a lot of trouble getting anything out of the candidates. It's possible that they were all just terrible, but I'm guessing it was more probably my approach.

I gave them a very simple test[1], and I was met with sort of deer-in-headlights stares. Hence forth I think I'll start with a problem and an example horrible solution.

[1]Presented the applicant with a screenshot from a desktop computer that couldn't connect to the internet. The screenshot showed several possible indicators (impossible network settings, cable unplugged, etc...).

[notahacker]

Extending it to interviews doesn't work partly because the findings are so unsurprising.

Permitting "I don't know" doesn't actually seem to help candidates get more correct answers in the study (looking at the actual paper, the group discouraged from saying "I don't know" actually got a slightly higher number of questions right at the first time of asking)

It simply means those encouraged to say "I don't know" guess wrongly fewer times - no surprises there - whilst still revealing their ignorance to the interviewer.

Applied to job interviews: interviewing people for a job by asking simple factual questions the interviewer knows the answer to is doing it wrong. If they're indiscriminately negatively marking "wrong" answers that aren't prefaced with an explanation that guessing is inadvisable, they're doing it even more wrong - how candidates answer questions they don't know is valuable decision making heuristic.

A more usual interview will involve many questions where there is no clear "correct" answer, in which case "I don't know" will usually be one of the worst possible answers. Even where the questions are fact-based, a decent interviewer should usually give more credit for how a person guesses than an admission of ignorance, in which case "I don't know" is neutral at best. Sure, some candidates that aren't good at guessing or are especially bad at bullshitting will appear worse than if they're encouraged to say "I don't know", but that's valuable information for the interviewer which lost by encouraging everyone to give a non-answer. Same applies if humility is a key requirement and "I don't know" actually is a decent answer.

TLDR: Since correct answers are unaffected, allowing candidates to say "I don't know" only improves the interview performance of weak candidates.

[jlgreco]

> "And I do mean worst."

I am not convinced that throwing INTERCAL at a candidate is a good way to roll. ;)

But seriously, I think that you are spot-on with this approach. Interviewing, done effectively, is about getting a fleshed out idea of the capabilities of the candidate, not just getting correct answers. Perhaps the best response to give or expect, when the interview gets stuck, is "I don't know, but..." Even on questions that aren't coding questions, these are often good responses: "I don't know, but [this is how I would find out]" or "I don't know, but [this is a topic or problem that I believe is related]" .

[jaggederest]

For what it's worth, my 'worst solutions' always involve a guy with a van driving around hassling people in person. Somehow people never accept my proposed solution, so I haven't been able to test it.

[j_baker]

> A good interviewer wants to get a look into how you think and how you approach a problem.

I consider that a red flag. In this case, the interviewer is almost certainly less concerned with whether or not you can do the job than they are concerned with whether you think like them.

Though I do like your suggestion to try offering a terrible solution to get the conversation started. Usually it's breaking the ice that's difficult.

[yeukhon]

I don't know who downvoted you, but I don't quite get what you are saying (why is that a red flag and what exactly do you mean that's a red flag?) Red flag as in it is theoretical (like "of course that would be nice.....but that's usually not true)? or red flag as in interviewer is tricking the interviewee to do bad job? (making bad impression to interviewer)?

[patrickyeon]

I've been in interviews where the interviewer had me play the guess-what-answer-I'm-thinking-of game, and that may be what j_baker is afraid of. I don't want to do that either when I say "get a look at how you think"; I want to see that you can attack a problem, not necessarily that you'll try the same things I would.

[yeukhon]

Absolutely. I rather have an interviewer questions me why I think my solution is a solution (even if it is a terrible n^3 solution).

[acdha]

That's a great technique and one which I particularly like because it also tends to be more representative of the real job: you almost always want to work with the person who says “Slow down, let's make sure we understand this…” when handed a hasty spec and proposed solution