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Steve Ballmer's incorrect binary search interview question

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Re: Steve Ballmer's incorrect binary search interview question

#102
post #100
post #10

The article implies that the interviewee assumes that the number is being chosen randomly, when Ballmer could actually be choosing adversarially. However, if the interviewee assumes that Ballmer is being adversarial, then you can pick a different value as your initial guess, which causes the probabilities to shift. Even the OP assumes that the interviewee will start guessing with 50, but, because of the way binary se…

If Ballmer is being adversarial, he won’t pick the number at the start, and always win. Of course you can set up the game such that Ballmer has to commit on a number at the start of the game (by sealing it in an envelope or whatever), but that wasn’t specified.

they’re being adversarial within the framed rules of the game, not breaking the rules of the game?

Re: Steve Ballmer's incorrect binary search interview question

#103
post #76
post #52

Earlier quoted context omitted.

What was the last time you were on the interview? I think like 70% of interviews I ever had were like they were there to prove how smart they are and how stupid I am. I suppose most likely to make me feel stupid and accept lowball offer.

One of the worst interviews I ever had was just like that. Often times, the "gotcha" part is just dumb and nonsensical, yet gives the interviewer(s) a sense of misguided (false) superiority, and wastes everyone's time. I would venture to say that 99% of the time it's complete un-indicative of how effective the candidate would be in the role. Referring to my aforementioned bad interview - the question, after all the t…

I had an interview at a major tech company with a similar thing, for a more managerial role.

The question was to estimate how many vacuum cleaners there were in the city we were in.

Fine, I did some estimation of how many vacuum cleaners per household and per office, across how many households and offices. Standard stuff.

Then the guy starts laughing and saying I'd failed because I didn't include discarded vacuum cleaners in landfills. Or the vacuum suction devices they put in your mouth at the dentist's office. And so forth. And then had to spend the next five minutes listening to him "teach me" how not to make assumptions. So I acted all polite and tried to fake "oh gosh thank you so much for enlightening me!"

Shockingly, I got the job, which required unanimous approval from all interviewers. Never met him again, and to this day I still have no idea whether this was supposed to be a test of estimation (which was easy to pass), a test of not making assumptions (which is dumb, but OK fine I failed), or a test of being appropriately professional and smiling in the face of complete bullshit (which I'd say I passed with flying colors).

I mean, in my professional life I've certainly had my fair share of customers and managers and coworkers who spout bullshit and you really do just have to lie with a smile and say "oh my gosh you're so right thank you for explaining that, I appreciate you so much!" Where you need to make them feel smart.

On the other hand, I just don't think he was thinking that far ahead.

Re: Steve Ballmer's incorrect binary search interview question

#104

Earlier quoted context omitted.

Like this one: https://rachelbythebay.com/w/2011/07/27/ohreally/ Yes, that happens, and elsewhere she goes on about culture in tech.

Is the guy's response really that far off? Each router checks its table for the destination, and if it doesn't know it, queries the next upstream router, its default route, the next hop. Each router likely ultimately informs you of the hand-off via a packet of some sort, and your then traceroute sends a ping/ICMP to each hop to learn how far away they are. He maybe could've been pushed to expand on what he did know i…

Is the guy's response really that far off?

When you think about it, the candidate isn't even that wrong. Back then, at university, a certain professor would explain the oral exam to the candidate at the beginning. He would explain that he would incrementally increase the difficulty and skip from area to area. The goal would be to find the limits of the student's knowledge, the student would walk away feeling terrible, and he, the professor, didn't enjoy the experience.

That's how it ought to be, but here? OK, candidate doesn't know ICMP well, next topic, no need to waste time and dig in.

Here's another unfavourable thought: some people with abusive childhoods react very badly to dominance displays, and here is Rachel engaging in just that. One wonders what had happened before.

Re: Steve Ballmer's incorrect binary search interview question

#106
post #2

Didn't Steve Ballmer start off at MSFT essentially in a biz ops role, supporting execs when the company was super small? Interesting how he became technical as the company grew. Pretty rare.

It's surprising the extent to which the tech community overfits towards classifying intelligent individuals as either exclusively technical or nontechnical. Recruiters are especially weak in this regard, e.g., if you've ever been effective at sales or people leadership, you are likely ineffective at swe or data science or vice versa. The most intelligent folks I've worked with are very diverse in their interests and…

> You can see this in an elementary school GT classroom.

GT?

Re: Steve Ballmer's incorrect binary search interview question

#107
post #45

Earlier quoted context omitted.

And then if Ballmer assumes the other party assumes he's being adversarial we get into game theory.

I have not really studied this but maybe choosing the guess randomly when the number of possibilities is even is already enough to counter an adversarial opponent. Note that 50 is not the only 'optimal' guess in the beginning. 51 is just as good.

Any number between 36 and 64 should be as good!

Re: Steve Ballmer's incorrect binary search interview question

#108
post #62

Is there a name for the fallacy where you attribute your success in life to your own intelligence, and thus assume that you are smarter than everyone else, and that you therefor must be right about everything? Sort of an opposite impostor syndrome?

> an opposite impostor syndrome? Dunning–Kruger effect https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect

Just because it's one of my pet peeves, this is not what Dunning Kruger says. What it says is that people who are poorly skilled in a task will overestimate their skill and those highly skilled will underestimate, but not that the poorly skilled estimate themselves to be better than the highly skilled.

From the wikipedia article you link:

> Among laypeople, the Dunning–Kruger effect is often misunderstood as the claim that people with low intelligence are more confident in their knowledge and skills than people with high intelligence.

Re: Steve Ballmer's incorrect binary search interview question

#109
post #10

The article implies that the interviewee assumes that the number is being chosen randomly, when Ballmer could actually be choosing adversarially. However, if the interviewee assumes that Ballmer is being adversarial, then you can pick a different value as your initial guess, which causes the probabilities to shift. Even the OP assumes that the interviewee will start guessing with 50, but, because of the way binary se…

And then if Ballmer assumes the other party assumes he's being adversarial we get into game theory.

Yes, this is a Nash equilibrium question.

Re: Steve Ballmer's incorrect binary search interview question

#110
post #91

Earlier quoted context omitted.

"as you, my interviewer, are a capable SWE I assume you gave me all the context needed to solve the problem". The interviewing game of asking clarification questions is silly and should stop. In the system design portion I can understand it, but not when asked a direct technical question. It's perfectly fine to ask followup questions with added constraints or just directly say that the specification is fuzzy and need…

> but not when asked a direct technical question. This is anything but a direct technical question though. > It's perfectly fine to ask followup questions with added constraints, but having the guessing game to figure out those constraints is nonsense. You say that. I say people being able to ask the right question is one of the most important skills to be a productive developer. So of course as an interviewer I want…

Sure, and there's a way to test the ability to ask questions that isn't some "gotcha" type question. As in interviewer you can just say "the specifications aren't clear, what questions would you might want to ask to clarify them?".

It's not like in the day to day work you go around defining specifications for every tiny function - the default specification are clear from the work environment.

Let's say you had to implement a "find dups in this array" at work, you probably won't go around collecting requirements for that, so asking that in an interview and having the silly dance of "Oh, the interviewee didn't ask if the array fits in memory or not" is silly imo - and doesn't show anything other than whether the candidate memorized the need to ask that or not.

and like I said before, fuzzy specification are more suitable for the system/product design part, and can also be part of the coding part, but they shouldn't appear as some "gotcha".

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