6÷2(1+2)=? - <AUTHOR> http://stevenclontz.com/blog/2013/03/17/order-of-operations/

<comment><USER3> According to Google, it's 9

<https://www.google.com/search?q=6%C3%B72(1%2B2)>

</comment><comment><USER4> >> The issue stems from the incorrect (but often subconscious) belief that there exists a Bible of Mathematics somewhere

Well, yes, I thought so. Most mathematical expressions are pretty standard and I'm surprising that there is no a definitive answer to this question.

The way I see it is:

      6/2(1+2)
      6/2(3)
      6/2*3
      3*3
      9

If I wanted to apply 2 _3 first, I'd write: 6/(2_ 3). Maybe I thought like that because that's how all calculators I've used work.

<comment><USER5> I am very surprised that people would evaluate the multiplication via juxtaposition after the division symbol. According to that method, 6 ÷ 2x would be evaluated as 3x, which I find extremely unlikely to be the intention of that expression.

<comment><USER4> Well, 6 ÷ 2x is similar to:

      6
      __
      2x

You've explicitly put spaces around it.

However, if you look at it like:

      6/2*x

Does 3x seems that unlikely?

<comment><USER5> Again, my point is that my interpretation depends on whether it's multiplication via the multiplication symbol, like 6/2*x, or multiplication via juxtaposition, like 6/2x.

</comment></comment></comment></comment><comment><USER6> I don't understand his idea of comparing the independence of the Continuum Hypothesis from the other axioms of set theory, which is a very deep and important result about (in essence) one of the limits of mathematical reasoning, with this little notational difficulty, which frankly is of very little interest, especially to mathematicians (you do run into this when writing parsers, sometimes...) He actually manages to say that this is "as stupid as" asking for a proof of the Continuum Hypothesis. Reminds me of people who get hung up on whether 1 is a prime number. Yes, no, maybe - <USER2> have defined it this way and that, it's a convention you can make without changing anything fundamental about mathematical reasoning.

Different systems of axioms lead to very different mathematical objects (compare Euclidean and non-Euclidean geometries). Different conventions lead to the exact same thing written slightly differently - if we say that clockwise rotation corresponds to positive change in angle (the opposite of current convention), we'll exchange plus and minus signs in a bunch of formulas, and nothing else.

<comment><AUTHOR> My (intended) implication was that answering the question

> What is 6÷2(1+2)?

without establishing the axioms of arithmetic is as impossible as answering

> Does CH hold in ZF?

without establishing some axioms of set theory.

Put another way, asking 6÷2(1+2) on the SAT is as ill-advised as asking an Introduction to Proofs course to tackle the Continuum Hypothesis with just some naive set theory.

<comment><USER6> Again, I think that's a very bad comparison - resolving this difficulty is not "impossible". You can choose whatever convention you like, and all that changes is the notation. Of course it's a bad test question, but it is not "impossible" or even remotely difficult for mathematics - it's just a matter of choosing a notation.

You seem to think that this question has something to do with the "axioms of arithmetic" - no, it doesn't, it's a matter of how you write things by convention. Operator precedence is not and has never been an "axiom". We can define plus to have the highest precedence, and get the exact same arithmetic we have now, written differently.

On the other hand, deciding the Continuum Hypothesis is "impossible" in a very fundamental way - Kurt Godel and Paul Cohen, two of the greatest mathematical logicians in history, proved that the Continuum Hypothesis is undecidable by mathematical reasoning as we can best formulate it, i.e. it is independent of the ZFC axioms. That's not a matter of choosing a notation for it.

<comment><AUTHOR> Whether you consider the properties of arithmetic to be axioms or some other word which describes a fact assumed without proof is a matter of semantics.

The point was that without a precise foundation for mathematics we cannot proceed - anything further is overanalysis for an article I wrote mainly for folks without our mathematical background. :-)

<comment><USER6> There is a fundamental difference between conventions of notation, and properties of the thing being notated, in this case arithmetic. I'm frankly surprised that someone with a mathematical background keeps mixing up the two. There are a dozen people in this thread of comments posting different notations - prefix, postfix, what have you. Do you think these define a different arithmetic? Now of course it's stupid to ask people a question without defining what you mean by your notation - you might as well mumble something and expect them to decipher it. But that is in no way equivalent to asking a question which is undecidable in mathematical logic (which is not necessarily a stupid thing to do). And features of some particular notation do not in any way, shape, or form, or by any stretch of semantics, constitute axioms, or properties, or anything else which belongs to arithmetic itself. Do you really disagree with that?

</comment></comment></comment></comment></comment><comment><USER7> (/ 6 (* 2 (+ 1 2)))

The answer is 1.

(* (/ 6 2) (+ 1 2)) would give nine but c'mon...that multiplication way over on the left came outta nowhere.

<comment><USER8> I prefer 6 2 1 2 + * / and 6 2 / 1 2 + * notation.

</comment></comment><comment><USER9>
      6/2(1+2)=6/2*(1+2)=6/2*3=(6/2)*3=(3)*3=9

This is pretty well defined, I feel:

\- Expand implicit multiplication to explicit multiplication (e.g. 2(1+2) becomes 2*(1+2))

\- Left-to-right precedence for operators of equal-precedence (divide and multiply)

The 2 is no more bound to the parenthesis than it is to the division operator.

Am I missing something?

<comment><USER10> When you have 6/2(3), it is not well define if the correct expansion is 6/(2 _3) or (6/2)_ 3\. In my experience with math, the intuitive answer is that implicit multiplication takes precedence. For example, say instead of 6/2(3), you had 6/2x. Following your convention, that would expand to (6/2)x, not 6/(2x). You might say that the () around the last number make a difference. However that would imply that 6/2x!=6/2(x). Which I find deeply unsettling if true.

Ultimitly, this is why we tend to use notation which uses placement to resolve these issues unambiguasly, without alot of parentheses.

<comment><USER9> I find it interesting you feel this way.

In my experience, it is pretty well defined:

0\. Evaluate (the inside of!) parenthesis, then

1\. Evaluate exponentials, then

2\. Evaluate division and multiplication operators, left to right

      e.g. 1 / 2 * 3 / 4 = (1/2) * 3/4 = ((1/2)*3)/4

3\. Evaluate addition and subtraction operators, left to right

Your issue seems to stem from the left-to-right concept (in order in which operators are encountered as you read, left-to-right).

Your example of 6/2x to me is clearly (6/2)x. What is 1/2x ? In my experience, textbook authors/professors/math teachers tend to be disambiguous and either use the horizontal line for clarity or use parenthesis.

I attended public schools in Ontario, Canada if it makes any difference.

Edit: Oh yeah, also I have never felt that implicit operators would take precedence. Interesting!

</comment></comment></comment><comment><USER11> I have never understood why you would process multiplication and division as separate reduction steps, besides for simplification in elementary-school learning materials. It seems completely arbitrary. Division is just multiplying by an inverse, and subtraction is just adding negative numbers. PEMDAS seems like something that is taught to you, and then never correctly explained.

<comment><USER12> BEDMAS (what I was taught in school) really throws some confusion in there concerning PEMDAS. Heh. We've started using PEMA in NZ to lessen confusion. I assume they go on to explain where division / subtraction went.

</comment></comment><comment><USER13> This is not mathematics, this is symbol manipulation. The author is correct, the answer here is that it is a badly expressed problem - with multiple possible solutions depending on the assumptions the audience makes.

In mathematics allowing your audience to make assumptions is very very bad...people are terrible at making and applying assumptions - just look at any studies into eye witness testimony.

Machines are just as bad, as they are loaded with assumptions of their programmers.

As a Computer Scientist, I absolutely hate coming across badly expressed formulas. Abstraction is key - why are there parentheses around the 1+2, what makes those separate...why not just write 3?? - In fact there are no variables in this problem, it is constant, just give me the constant...or tell me why you have defined it this way.

Implicit operations and ordering may save you a couple of characters but generate essays worth of confusion.

</comment><comment><USER5> Obviously, the author is right that there is no universal objective definition of the order of operations. Still, I find it surprising that anyone with a high school level mathematics education would perform the division via the obelus (÷) before the multiplication via juxtaposition.

<comment><USER14> In high school (and college) I've always been taught that multiplication and division have equal precedence and should be evaluated in the order in which they are encountered.

<comment><USER5> Was multiplication by juxtaposition ever mentioned explicitly? I was taught to give them equal precedence, but that was explicitly for the division symbol and the multiplication symbol (* or x). Juxtaposition, like 2x or 2(2+1), was always considered to have greater precedence than the division and multiplication symbols.

<comment><USER15> Nope, never heard that in my 13 years of school in Germany.

</comment></comment></comment></comment><comment><USER16> > In the real world of mathematics, this is as stupid a question as me asking > "Is there a mathematical size bigger than the amount of integers but less > than the amount of real numbers?" [1] because you can't answer it without > going through a lot of trouble to specify the "axioms" (basic assumed rules > for doing mathematics) you want used on the problem.

I don't think this analogy holds very well--a curious student could reasonably and earnestly ask about the continuum hypothesis, since it's not at all obvious from first principles that the answer depends so heavily on obscure set axioms. On the other hand, the order of operations question seems to have been designed to confuse people and stir up meaningless, unresolvable arguments over PEMDAS.

</comment><comment><USER17> Computers will conclude the answer is 1 as they will prioritise the multiply.

Now us humans will get 9 as they will do the 6/2 and then multiply the result with the (1+2) for 3x3.

Now given the multiply is implied and computers like to have that symbol in many languages and the divide sign as again a form not overly used in programming languages, then it is clearly expressed in a form for human consumption. With that we imply the 6 divided by 2 is in its own bracket and will think it is 9, then we will think again if we know computers and then think 1.

Moral being whilst lots of brackets and braces can look untidy, they do clarify beyond doubt.

<comment><USER18> No, they won't. Computers will compute it as nine because they evaluate the parenthesis, then go left to right.

6 / 2 (1 + 2)

6 / 2 * 3

3 * 3

9

</comment></comment><comment><USER19> I blogged about this nearly two years ago:

<http://www.solipsys.co.uk/new/AMatterOfConvention.html?HN>

<comment><USER20> Nice, i would have said 9 just because that's how C interprets it.

float x = 6 / 2 * (2 + 1); // x == 9

<comment><USER21> Right, but you also had to explicitly add the asterisk for multiplication. I thought the same thing, but the remarks on juxtaposition do have a point. For example, if an integer were callable, you'd do the function call-- 2(2+1)--independantly of the division.

</comment></comment></comment><comment><USER22> The title (on his website) contains the wrong formula. I've skimmed the post a few times, wondering why the correct answer wasn't twelve... Then I saw it :/

</comment><comment><USER23> Is it 1+3 or 1+2? Title does not match content.

<comment><AUTHOR> Thanks for the catch!

</comment></comment><comment><USER24> It's funny because in other interpretations the "%" symbol evaluates to the modulus operator and this brings up another possible result. 6 mod 2(1+2) = 6 mod 6 ~= 0 mod 6

</comment><comment><USER25> Wouldn't it have been easier to just express this question as 6/2*3? The addition part doesn't seem to add anything to the point of the article (no pun intended).

<comment><AUTHOR> The question is taken from a Facebook post making the rounds. The parentheses are important however, as they introduce a new ambiguity: does the implied multiplication from the open parenthesis trump the division symbol on the left?

Put another way, does it fall into the Parentheses section or the Multiplication section of the PEMDAS order of operations? (Or whatever mnemonic your country uses.)

<comment><USER25> Why would the multiplication fall in the parenthesis section when it clearly isn't in a set of parenthesis? 6÷2(1+2) expands to 6÷2*(1+2). The items inside the parenthesis first and there should be no ambiguity about that.

</comment></comment></comment><comment><USER26> [http://www.wolframalpha.com/input/?i=6%C3%B72(1%2B3)&t=c...](http://www.wolframalpha.com/input/?i=6%C3%B72\(1%2B3\)&t=crmtb01)

<comment><USER27> I think you meant: <http://www.wolframalpha.com/input/?i=6%C3%B72%281%2B2%29>

But that's just how WolframAlpha does it. The article is about the ambiguity in the mnemonic we're taught in school. I thought the correct answer was going to be '1'.

</comment></comment><comment><USER28> just as a data point:

as google, wolfram alpha (a mathematica "frontend") interprets it as (6/2)*(1+2).

[https://www.wolframalpha.com/input/?i=6÷2(1+2)&dataset=](https://www.wolframalpha.com/input/?i=6÷2\(1+2\)&dataset=)

(and even with a variable juxtapositioned it's interpreted like that.)

but right, that's no real metric for mathematical use. (i still think the result is 1.)

</comment><comment><USER29> It's one. He himself said parenthesis takes precedence. So:

6 / 2(3) <== Parenthesis still there

6 / 6

1

<comment><USER12> wooosh

\--

It's 9, you've added some invisible brackets in there.

6 / 2 * (1 + 2)

6 / 2 * 3

3 * 3

9

</comment></comment><comment><USER30> When converting it from infix to postfix, it returns 6 2 / 1 2 + * which returns 9. I prefer this point of view.

</comment><comment><USER31> I was taught to handle parenthesis first before multiplication or division so the answer is clear to me to be 1.

<comment><USER18> Well, is the implied multiplication technically part of the parenthesis, though? I've always been taught the stuff _inside_ the parenthesis takes precedence, but outside is irrelevant because it's not technically "part" of the parenthesis statement.

It's like how programming works:

6 / 2 * add(1, 2)

This would obviously evaluate to 9, because the "add" function would simply return a value and the rest of the statement would be evaluated from left to right. In this case, the first 2 is not related to the "add" function in any way.

</comment></comment><comment><USER32> That "divide-by" symbol can suck my left nut.

</comment><comment><USER33> 1

</comment><comment><USER34> The way you know this question is dumb? It was written by someone who either doesn't understand how to write math to be readable, or was written by a troll. The use of that division sign, ironically, doesn't make it any easier to determine, although there's surely a subset of FB idiots (the same that would waste time on this in the first place) that wouldn't understand it written as 6/2(1+2).

<comment><USER4> You wasted time on _this_ by writing this comment.. not sure why you're discriminating others as idiots.

<comment><USER34> I'm 96% sure you missed the point of my post.</comment></comment></comment>


Arizona State Students from China Detained at LAX, Denied Entry to US - <AUTHOR> https://www.usatoday.com/story/news/nation/2019/08/30/arizona-state-students-from-china-detained-denied-admission-to-us/2171189001 <comment><USER2> "The Chinese students were deemed inadmissible to the United States based on information discovered during the CBP inspection," the CBP statement said.

Look. The Feds don't always have bad reasons for doing things. I know we have a lot of problems and the social media and computer searches aren't something I find myself condoning, but before we jump to any conclusions we should at least wait to see why exactly they were denied entry. It could be BS, or they could be targeting Hong Kong supporters amongst Chinese students currently studying in the US or Canada or elsewhere. It seems odd to me that the Feds would target these specific 9 students so I think it's worth the time to wait until we hear more.

<comment><USER3> > before we jump to any conclusions we should at least wait to see why exactly > they were denied entry

I understand it's not as easy, but we should at least try for "innocent until proven guilty" when it comes to the government denying privileges. I'm all for the government denying entry, but it should be clear what the offense was.

<comment><USER4> >we should at least try for "innocent until proven guilty"

This method of justice is reserved for our court system inside the US and most likley not work for our borders due to the fact agents must make educated or gut decisions.

>I'm all for the government denying entry, but it should be clear what the offense was.

This seens to be a contradiction to your other thought.

<comment><USER5> > This method of justice is reserved for our court system inside the US and > most likley not work for our borders due to the fact agents must make > educated or gut decisions.

You mean there are two standards in USA one at the borders another in the country.

So all countries denying reporters, human rights workers or dissidents or protestors to enter their borders are doing it correct, because the rule of law is inside borders not outside.

So your thought justify very much the border agents analysing your phones and electronic media before entering, like the way in recent memories happening in Hong Kong borders due to protests.

You might, but personally I cannot agree with such a notion of dual standards of law. I understand entry to a country and visa is a privilege not a right. But if a country believes in rule is law and on foundations of " _Innocent until proven guilty_ ", then it should abide by it.

<comment><USER4> >You mean there are two standards in USA one at the borders another in the country.

Yes. Also there are seperate policies and rules for citizens and non- citizens at the border.

>So all countries denying reporters, human rights workers or dissidents or protestors to enter their borders are doing it correct, because the rule of law is inside borders not outside.

This discussion pertains to entry into the US.

<comment><USER6> _This discussion pertains to entry into the US_

Most of the students will have been in the US before, they are continuing their degree and just went home for the summer. If the FBI or whoever has something on them they can apply for a warrant and have them arrested. But the government instead chose not to admit them at the border.

It goes the opposite way as well, if the student chooses not to leave the government has to find something of substance and convince a judge, just saying "I want you out" doesn't cover it. Nothing of this makes sense, and as far as national security goes, I find it hard to believe that students are permitted near classified data.

</comment></comment></comment></comment></comment></comment><comment><USER7> A few days ago a Palestinian Harvard student was denied entry into the US after the CBP searched her phone for social media content and found anti- American posts made by her friends that she had no control over.

[https://www.thecrimson.com/article/2019/8/27/incoming- freshm...](https://www.thecrimson.com/article/2019/8/27/incoming-freshman- deported/)

<comment><USER8> Was covered in TFA:

> Earlier this week, the Harvard Crimson reported a Palestinian student was > detained by Customs and Border Protection and sent home to Lebanon. In that > instance, the student claims customs officials found posts from people that > included political views that opposed the U.S. on his friends' list.

</comment></comment><comment><USER9> Maybe I'm just dense - but it seems much more sensible to grant or deny permission to enter from a flight's originating airport.

<comment><USER10> _it seems much more sensible to grant or deny permission to enter from a flight 's originating airport._

It's a thing that happens in every country. That's how people occasionally end up living at airports or days, weeks, or months. They can't enter the country, and they can't go home for various reasons. (There was a movie made about this a while back, I don't remember if it was about a real person.)

Back during the first bird flu scare (90's, I think), one of my family members was denied entry into Hong Kong from Macau because she was scanned with a high temperature. No country is going to say, "Hey, you're undesirable. How about you stay here with us?"

<comment><USER11> The movie is The Terminal. Supposedly based on this person

[https://en.wikipedia.org/wiki/Mehran_Karimi_Nasseri](https://en.wikipedia.org/wiki/Mehran_Karimi_Nasseri)

Interestingly, there's also

[https://en.wikipedia.org/wiki/List_of_people_who_have_lived_...](https://en.wikipedia.org/wiki/List_of_people_who_have_lived_at_airports)

</comment></comment></comment><comment><USER12> It's unclear when it happened. 12 hours ago or 12 days ago?

If CBP is concealing information for a long time - this will certainly cause lots of negative grief amplified by press.

</comment><comment><USER13> Meanwhile the Chinese visa process is extremely strict and a Chinese citizen has to account for you and explain why you are there. They are finally getting reciprocity in the actions the Chinese government takes against everyone else.

<comment><USER14> A Chinese visa is _way_ easier to obtain for an American than vice versa.

<comment><USER8> Is that across the board or for certain types of visas?

<comment><USER15> For normal tourist and business visas it certainly is.

A US citizen applying for a Chinese visa has little concern about being denied so long as they do not in any way resemble a reporter. A young adult Chinese citizen applying for a US visa is probably going to be turned down and everyone will have to travel to a consulate for an interview. Despite a pile of Chinese visas I have never so much as laid eyes on a Chinese consulate.</comment></comment></comment></comment>


A gentle introduction to HDBSCAN and density-based clustering - <AUTHOR> https://towardsdatascience.com/a-gentle-introduction-to-hdbscan-and-density-based-clustering-5fd79329c1e8 <comment><USER2> Good article.

I used HDBSCAN in my master's thesis. It works well with high dimensional data. If you're using it for high dimensional stuff I would recommend working with Uniform Manifold Approximation and Projection (UMAP) to visualise. I think it is made by the same author as HDBSCAN.

I wish they also talked about Density-Based Clustering Validation (DBCV) which can be used to calculate the mathematical stability of the clusters (for hyper parameters), apart from just looking at hierarchies.

<comment><USER3> This is sorta true, but not quite. Leland McInnes and John Healy (the creators of UMAP), do in-fact have an amazing paper on HDBSCAN, but it's not inventing it. In their paper, [https://arxiv.org/pdf/1705.07321.pdf](https://arxiv.org/pdf/1705.07321.pdf), they introduce AHDBSCAN which is a great extension of HDBSCAN to dramatically improve it's performance.

Their work is great but just wanted to save people a google in case they were interested.

<comment><USER4> Never heard of AHDBSCAN, thank you for sharing!

</comment></comment></comment><comment><USER5> Is there a difference between HDBSCAN and DBSCAN (commonly used for point cloud processing). The idea seems the same but I guess I never heard it called HDBSCAN.

<comment><USER6> HDBSCAN == Hierarchical DBSCAN, an extension of DBSCAN that produces hierarchical clusters.

</comment></comment><comment> bra-ket any article on clustering should mention ANN benchmarks and state of the art [http://ann-benchmarks.com/](http://ann-benchmarks.com/)

<comment><USER7> Uhh, why? They're not really related to each other...

<comment><USER8> ANN is the building block of density estimation. If I recall correctly that's the bottleneck for density-based clustering as its various algorithms then take advantage of faster yet algorithms (sort, union-find, spanning-trees..). While very interesting I am not sure this gentle introduction is the best place to discuss ANN.</comment></comment></comment>


Hiring for startups: You're doing it wrong - <AUTHOR> http://blog.zumper.com/2014/04/kissing-goodbye-to-the-ohare-test/

<comment><USER2> And if you are a prospective employee joining a company that is planning to have "oh shit" moments, just make sure you are being compensated with a lot of equity. There basically is no worse deal than joining a risky company at the stage where they already have some funding and employees.

Assuming you are the resilient type who is capable of founding a startup, you'd get a much better deal either founding your own company or just joining a runaway success startup and get experience and build your network while saving up dough.

<comment><USER3> I greatly second this. I'm doing a job search now and have already had to turn down three offers from early stage startups, because the compensation is delusionally low. I'm talking 40-60k below market rate, with pitiful stock options to make up for it. I often wonder who would even let themselves be taken advantage of so strongly? Why would any halfway decent engineer take 65-80k with 0.25-0.5% equity?

Either be a founding member, or join a larger already successful company who will give you market compensation. Don't get caught in the middle soup of being taken advantage of and often being part of a very poorly run companies.

<comment><USER4> _I 'm talking 40-60k below market rate, with pitiful stock options to make up for it. I often wonder who would even let themselves be taken advantage of so strongly? Why would any halfway decent engineer take 65-80k with 0.25-0.5% equity?_

        see news about $100M exits ==> 0.5% == $500k
        heard mention of a 10% success rate ==> $50k expected value
        $50k == (market_rate - salary) ==> sounds about right

Which of course misses that (1) the utility of large amounts of money isn't linear (expected value doesn't work that way on single occurrences); (2) future money should be discounted by some rate; and (3) your equity will get diluted.

And that the slaray difference is _per year_ , and the equity is a one-time thing. And whatever else I missed.

<comment><USER3> Yeah, though this is napkin calculations, 10% chance of $100M exit is wayyyy too high. I would love for someone to cite a real figure, but I would guess it's less than 0.5%.

Having been through a $50M acquisition with some options, it's really not worth the risk at all. I keep with the opinion: anyone who sacrifices salary for options is a fool. I also suspect the people getting ripped off here tend to be younger people who don't really know what they're worth, don't know just how much money they're giving up.

</comment></comment></comment></comment><comment><USER5> The article seems to subtly suggest that if you do not have an advanced degree [1], you do not have "brains." As someone who has "brains" but has chosen not to pursue and advanced degree, if I were working for the author, my reaction would be to question this person's judgment on several levels: 1) Implicitly putting down those who work with him who don't have advanced degrees. 2) Susceptibility to autobiographically-based irrationality, aka too much Koolaid.

Why is this an irrational viewpoint? Sure, someone who has an advanced degree is unlikely to be dumb. But as any remotely educated person should know, it does not follow that someone who does not have an advanced degree is not smart.

I think the obsession with advanced degrees is fascinating though. Do people _really_ believe that getting an advanced degree will make one a more productive web developer? Are the years spent getting that advanced degree remotely comparable to years of meaningful industry experience? Or comparable to using the countless online resources to educate oneself in topics that are directly applicable to web development?? Hint: no.

[1] "Brains don't matter as much as resilience in your first couple of years as a startup. I borrowed a lot of money to put myself through one undergraduate and two masters programs so, yes, it hurts to write that."

</comment><comment><USER6> Hire who's right for _your_ startup, not who someone (who may have really only written this blogspam as a way to get eyeballs on job postings) tells you to hire.

These "how to hire" posts are getting so tired. Not because its a bad subject but because they are completely empty.

<comment><USER7> I agree. At the end of the day, it always comes back to personality types and drives. Each startup needs different things in different phases. Maybe a really smart coder is exactly what a non-technical co-founder might need, whilst a resilient hustler is what a well groomed hacker needs. In general, universal quantification over statements that are not law-like are doomed to fail. (<\- yes there is an embedded pun there).

</comment></comment><comment><USER8> I like this concept, you're right that brains and resilience aren't always the same. Some really smart people need stability and can't handle rapid change.

However, I do think culture-fit (which is way more important than personality) is as important of a criteria, even more so for early stage start-ups. When you're building an organization, you have a vision not only for what you want that org to achieve, but what you want it to look like. In an early stage company, even one person that goes against that culture could represent 25% of the company. Their mere presence serves to undermine what you want to build, and as they say... the one rotten apple rots the rest.

I'm not saying these are bad people, a culture-mismatch at one org is a culture-fit at another org, but this is an important criteria. I recognize also that this really drags down the recruiting process. There are some ways to get around it (e.g., trial work weeks, part-time contractor positions), but these have been discussed on HN before and are not immediately relevant.

Just more food for thought.

</comment><comment><USER9> Paul Graham talks about hiring people who aren't hapless: [http://www.paulgraham.com/relres.html](http://www.paulgraham.com/relres.html) (2009)

Which I agree with. I've worked with people who started crying at the first sign of trouble. I've worked with people who wanted to make every single encounter into a fight. Both of these are completely toxic to a start-up.

I really worry, though, about these hiring practices that are just psychological tests designed by non-psychologists, like this:

 _Hire people who emailed you a dozen times before you had a chance to reply_

I usually stop emailing after 3 or 4 times, figuring that that 4th email already made me look desperate.

I've said it before and I'll say it again: a lot of these "how to find good employees" are as rigorous as dating advice in the latest issue of _Cosmo_.

<comment><USER10> Coming from an investment management background, it has been hilarious to see people espousing all manner of foolish nostrums about tech hiring, showcasing biases that have proper names in the investment community,

My favorites are of the "never hire Xs" variety, as a manifestation of the snake bite effect. Woah... what happened between you and someone with a dual CS/Art History major?

</comment></comment><comment><USER10> I would reframe the suggestion as two ideas. 1) "hire for your culture" and 2) conditioning on a cultural expectation of individuals putting up with lots of problems on their own, "make sure new hires can cope."

The latter is an important point, but the idea that all startups have this attitude towards employees and crisis management is not accurate.

How important is it for potential candidates to know if the culture at a startup they are considering working for has these values? I'm guessing a blog like this turns off a lot of people, but to the author's point, not anyone they would hire. Effective :D

FD: back end dev at Mighty Spring, we do startup hiring. (mightyspring.com)

</comment><comment><USER11> Though one could argue if you higher smarter people you might have less "oh shit" days?

<comment><USER12> Not everything is about code and servers, a lot of the "oh shit" stuff comes from external factors that even a intelligent person would not be able to foresee or avoid. I think the point is to hire smart resilient people, not just smart people.

<comment><USER13> I agree with this comment as well as the overall theme of the article. Smart people may be able to foresee potential "oh shit" moments, but realize that multiple factors which contribute to those moments are outside of their control. Therefore, smart and resilient people will be able to take the hits and adapt as they dig themselves out of the lows.</comment></comment></comment>