How you end up hiring a mathematician while looking for a programmer.
How you end up hiring a programmer while looking for a mathematician.
The math in this problem is rather simple, actually.
Steve Ballmer's incorrect binary search interview question
191–200 of 257 posts
Re: Steve Ballmer's incorrect binary search interview question
#192Earlier quoted context omitted.
Interviewing is by no means the perfect way to assess a candidate, but ultimately that’s what the purpose is. If I just tell candidates what I want them to say upfront, then why even bother with it at all? I want to assess what qualities they have that I want/don’t want, and what qualities they don’t have, as best I can. They don’t need to be perfect. Skills can be trained, personality characteristic much less so. Pe…
What you should care is a behavior. You should be open about what is expected. People change behavior all the time depending on the situation/group/company/context.
People can change the behaviour for brief periods. But who they are day in day out is going to be pretty consistent. Telling people how I would want a good candidate to behave during an interview doesn’t help at all with candidate selection. An inclination towards saying things they think people want to hear is a characteristic I’d like to select out of my candidates as well, so perhaps I’ve been killing two birds with one stone here…
Re: Steve Ballmer's incorrect binary search interview question
#193How come their software is so shit if they are so good at coming up with clever interview questions?
Re: Steve Ballmer's incorrect binary search interview question
#194Earlier quoted context omitted.
Is the landfill actually 'in' the city, or in a rural area outside the city limits? I had a similar interview years ago - something like "how many windows are there on houses in our town?". Wasn't quite that, but I asked up front if "houses" meant just physical standalone houses, or if they meant living spaces, including apartments/dorms, etc. I got clarification, gave some estimate with some reasoning, and was then…
Yes, I have used questions like this before for junior roles and the notes for the interview were something like: - Asked/did not ask clarifying questions - Did/did not (or could not, on prompting) verbally walk through their reasoning - Could/could not articulate which assumptions they felt were most important/why Nothing about the actual content of the question itself, or if your answer was approximately correct (I…
Yeah, I think there's a possible pitfall with using this as an interview technique though.
When you're in a real situation with a customer or user, you ask tons of questions. You use a lot of common sense to figure out what they really want, what's actually important, etc.
But often times these interview questions -- like how many vacuum cleaners in a city -- don't need any further questions asked. The idea that you'd count vacuum cleaners in landfills, or dental suction devices, is just silly. In real life, if someone wanted to know about the vacuum cleaners in landfills too, they'd tell you in the first place.
If an interviewer wants to see if someone can ask clarifying questions, they'd better come up with a scenario where it would make sense to ask them in a normal conversation. Scenarios that are genuinely ambiguous to anyone with common sense.
Otherwise interviews become this weird cargo-cult thing where you have to learn that interviewers present common-sense clear questions, but you have to ask silly clarification questions that you wouldn't in real life, just so somebody can check a box that you asked questions.
Re: Steve Ballmer's incorrect binary search interview question
#195Earlier quoted context omitted.
That SME guy sounds like an asshole, but I used to have an interview technique where I’d ask increasingly specific and low level questions about the candidates area of expertise until it got to the point where I’d be pretty confident they wouldn’t know the answer off the top of their head. I wasn’t adversarial or rude about it, I just wanted to find out if they were comfortable saying “I don’t know”, because not know…
I've been on the other side of that table. The interviewer stated in advance that the questions would get harder until I couldn't answer anymore, and that's OK because he wanted to see where my knowledge stopped. That clarity made it much more fun than stressful. I felt alright saying "I think the answer is X, but it could possibly be Y, and here's what the different implications would be". But for the luvagod, pleas…
I do this, but with the goal to find a specific thing they don’t know in an area they do know. Then I want to see them work out what a reasonably possible answer would be
Re: Steve Ballmer's incorrect binary search interview question
#196Earlier quoted context omitted.
I've been on the other side of that table. The interviewer stated in advance that the questions would get harder until I couldn't answer anymore, and that's OK because he wanted to see where my knowledge stopped. That clarity made it much more fun than stressful. I felt alright saying "I think the answer is X, but it could possibly be Y, and here's what the different implications would be". But for the luvagod, pleas…
I like that idea, and I may need to steal it. I have this tendency of asking candidates questions, and if I feel like they’re demonstrating very strong knowledge then I may toss them a few extremely obscure questions for bonus points, but I never expect candidates to get them right. But this up-front approach of setting expectations seems like a better way to go.
Please do. I think you'll get more signal, too. If I were worried that I've forgotten something very basic I'm expected to know, you're not going to learn much about me other than that I don't do my best work during interrogations. Tell my I'm not expected to know a thing, and then there's lots of room to talk about it, and I can show you that maybe I'm at least familiar with the ideas even if I've forgotten the particulars.
Re: Steve Ballmer's incorrect binary search interview question
#197Earlier quoted context omitted.
I've been on the other side of that table. The interviewer stated in advance that the questions would get harder until I couldn't answer anymore, and that's OK because he wanted to see where my knowledge stopped. That clarity made it much more fun than stressful. I felt alright saying "I think the answer is X, but it could possibly be Y, and here's what the different implications would be". But for the luvagod, pleas…
I do this, but with the goal to find a specific thing they don’t know in an area they do know. Then I want to see them work out what a reasonably possible answer would be
I'm 100% fine with that. I had one interview where we ended up talking about the best data structures for a visual editor to store text files in-memory. It wasn't related to my day job at all, but I walked away feeling like I'd learned something, and the interviewer got to watch me reason my way through unknown territory to see how I handle such things. That was fun. I have no idea if I got the "right" answer or not, but it was at least defensible, and I stumbled across some ideas that he seemed to find unexpected and interesting. I ended up getting the job.
What made it enjoyable was me knowing that I wasn't expected to know the gory details of how text editor internals work.
Re: Steve Ballmer's incorrect binary search interview question
#198Earlier quoted context omitted.
They don't know what the interviewer wants to hear. There are places where every admission of not knowing something is held against you.
If the employer would hold that against you, it's not a place I'd want to work. Not sure about you.
Hard agree there. I'm quick to say "I don't know (yet)" because I don't want to waste everyone's time while I stumble through a bunch of made-up answers trying to sound smart. If I were punished for admitting I didn't know the details of something, I'd leave in a heartbeat.
Re: Steve Ballmer's incorrect binary search interview question
#199I recently interviewed for a senior level role for a complex domain (payments), this is an area I have more than a decade of experience. The interviews went flawlessly because I know payments inside out, not just in US but in UK and most EU jurisdictions. The funny bit is that the role being senior, influencing, soft communication skills and managing conflict are even more important than the subject matter expertise…
That SME guy sounds like an asshole, but I used to have an interview technique where I’d ask increasingly specific and low level questions about the candidates area of expertise until it got to the point where I’d be pretty confident they wouldn’t know the answer off the top of their head. I wasn’t adversarial or rude about it, I just wanted to find out if they were comfortable saying “I don’t know”, because not know…
I remember some experiences where an interviewer thinks they are doing a deep reach for something they think should be an "I don't know", but it happens to be something you do know. Sometimes they think you're bullshitting or arrogant for this.
Judging people and getting an accurate read on people is hard. Often people are overconfident in their ability to do it.
Re: Steve Ballmer's incorrect binary search interview question
#200Another stupid gotcha: Ballmer states the question as "I'm thinking of a number between 1 and 100." He does not state that the number is an integer. If he's thinking of anything other than an integer, you're unlikely to be successful in finding it via binary search.
He also didn't state that the number is always in the set {59}, so you will always win 5 dollars.