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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

#131

Post by ozim »

enneff wrote: post #123
ozim wrote: 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.

It’s been a long long time since I was interviewed for a job, but I have conducted a lot of interviews since then and any signal that the candidate has engaged with the question and has interesting thoughts about it is a huge plus. FWIW I would never ask these kinds of gotcha questions. I just give simple programming problems and talk through solutions with the candidates, and then throw in complications to the quest…

Good for you, as you look for someone to work with, not someone to cut down their offer.

I am basically doing the same as I also interview people - but I also check the market from time to time as I am not company owner.

But I basically don't care about the offer if company pays guy much or not it is not my money and I only win if I get a smart, nice person who knows his job to work with.

Re: Steve Ballmer's incorrect binary search interview question

#132

Post by tcgv »

dustincoates wrote: post #108
tcgv wrote: post #62

Earlier quoted context omitted.

> 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 clai…

My response was directed specifically at the OP's second question, about the "opposite" of impostor syndrome, and not the first one.

The dunning krugger effect is widely regarded as the polar opposite of it:

- "If the Dunning-Kruger effect is being overconfident in one's knowledge or performance, its polar opposite is imposter syndrome or the feeling that one is undeserving of success. People who have imposter syndrome are plagued by self-doubts and constantly feel like frauds who will be unmasked any second." [1]

- "This is the opposite to the Dunning-Kruger effect. The Imposter Syndrome is a cognitive bias where someone is unable to acknowledge their own competence. Even when they may have multiple successes they struggle to attribute their success to internal factors." [2]

- "The opposite of the Peter Principle and Dunning-Kruger effect is the imposter syndrome. This is when smart, capable people underestimate their (...)" [3]

[1] https://www.psychologytoday.com/intl/basics/dunning-kruger-e....

[2] https://www.leedsforlearning.co.uk/Pages/Download/28541a2c-3....

[3] https://www.forbes.com/sites/jackkelly/2022/07/12/what-the-p...

Re: Steve Ballmer's incorrect binary search interview question

#133

Post by Someone »

kibwen wrote: 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…

> I'd be interested to see someone do the analysis of what the optimal random-offset-selection algorithm would be to counter trivial adversarial choice

If you know your opponent picks a number uniformly from all numbers that lead to a maximum of guesses, the optimum strategy is a binary search between those numbers, making sure to pick one of those numbers at each turn.

The problem stays completely symmetric under this condition, so there would be two (maybe four due to edge conditions) optimal first guesses summing to 101.

In general, I think the trick still is a binary search where each guess splits the range of options in halves of equal expected/min/max cost (depending on whether you want to optimize for expected/min/max cost).

Re: Steve Ballmer's incorrect binary search interview question

#134

Post by kgla »

AmericanChopper wrote: post #128
throwaway_1more wrote: post #124

I 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…

They don't know what the interviewer wants to hear. There are places where every admission of not knowing something is held against you.

Re: Steve Ballmer's incorrect binary search interview question

#135

Post by potamic »

throwaway_1more wrote: post #124

I 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…

> they threw an obnoxious senior manager that kept interrupting me as I calmly answered the questions

This is a red flag. To me this signals that a company not only has a toxic culture, but embraces it. Such places attract personalities who love conflict and once there are enough people, they set the culture.

What doesn't get said often is that conflict is a failure of leadership. Often all it takes to resolve conflict is for one very senior leader to snap their fingers and say, "Guys, I want you two to make this happen". But what happens is that leadership is either far too disconnected from the ground to align their teams, or they constitutionally advocate conflict within their teams in the name of competitiveness. Either way, such places can be hell to work in.

Re: Steve Ballmer's incorrect binary search interview question

#136

Post by shepherdjerred »

thaumasiotes wrote: post #106
__coaxialcabal wrote: post #36

Earlier quoted context omitted.

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?

https://en.wikipedia.org/wiki/Gifted_education

Re: Steve Ballmer's incorrect binary search interview question

#137

Post by auselen »

kibwen wrote: 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…

Genuinely asking - not directly to OP of course, wasn’t this how people were playing the game when you were kids? Not as rigorous, but you intuitively try offsets to get lucky and find the number in fewer tries?

Re: Steve Ballmer's incorrect binary search interview question

#138

Post by greenavocado »

justusthane wrote: post #59

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?

Main character syndrome

Narcissistic Personality Disorder

Sociopathy

Re: Steve Ballmer's incorrect binary search interview question

#139

Post by gweinberg »

kibwen wrote: 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…

No it doesn't, it's quite clear that Ballmer can be choosing adversarially. The point is that even if Ballmer chooses randomly and the interviewee plays optimally given this, the game still has a negative expectation value, and that is enough to be sure the game is a loser for the interviewee.

The post never answers the question "so what is the real expectation value", which is a more difficult question. But I think if the interviewee chooses a number randomly from 40-60 as the first guess and does a binary search from there, Ballmer can't really improve on choosing his initial number randomly.

Re: Steve Ballmer's incorrect binary search interview question

#140

Post by a_wild_dandan »

caster_cp wrote: post #89
justusthane wrote: post #59

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?

Fundamental attribution error https://en.wikipedia.org/wiki/Fundamental_attribution_error

Let’s start calling these stories FAErytales.
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