skysight-inc/HackerNews huggingface dataset:
Here's what I personally did when I had an idea for a startup:

1. Decide where it's going to be most useful & get a lot of traction: desktop, web, or mobile. I had no second thoughts about going mobile since the problem I was trying to solve was mobile-related.

2. Design the screens. It doesn't have to be pretty, and don't take too much time doing it because whatever you write down will 1: most likely change during the dev process, and 2: most likely change upon testing it with your users and receiving feedback. Just use it as a guide. Then, code.

3. I don't think investors would be willing to give you some seed fund for a product that doesn't even exist yet. So definitely get started with at least a working prototype, would be great if you have some data to back that up (what did your users say, how many downloads have you had, how much money did you make from it, etc etc).
"Lawnchair" Larry Walters
I agree with your underlying point, but due to a weird quirk of Wikipedia history, Catholicism in particular was for quite some time way over-represented; in the initial land-rush to populate Wikipedia with content, they grabbed a number of out-of-copyright encyclopaedias whose text were already in digital form, and one of these was an old edition of the Catholic Encyclopedia from 1913. With the strange result that the very most obscure topics in Catholicism were actually pretty well-covered, though often with information that was a century out of date! Even now you can find articles that have been barely tweaked from their 1913 form.
I think that GitHub merely shifts the "dark matter" problem. I think your assertion about "rockstars" applies to GitHub just as well - for every person with an impressive GitHub account, there are tens of people who are better, toiling in obscurity.

The point is that you can't just look for people who are famous or prolific on blogs or twitter or GitHub or whatever else.
Linux Group Tests - Part 1 - Linux Links - The Linux Portal Site
What is the goal? If it's to test the mathematical ability of someone who you want to hire to code it might make sense to ask some probability questions.
I'm not sure what you mean by the second point. Three numbers whose product is prime? Did you mean sum?

Edit: Nevermind - I just figured these out. Makes me feel a bit dumb now. That's what I get for not doing math for a few years. I really liked the last one - got me thinking.
This one is just too much geek knowledge I think.
E.g. I have read about it a bunch of times and I completely suck at math.

Something less "cool" would be more apt imo (fizzbuzz itself is rather uninteresting).
You can now transfer Google+ connections between accounts
> The total number of people who signed up for a free trial dropped, but that's only because there are a bunch of people who aren't a good fit for the service

This is the real benefit of free/no signup. If you can weed out your customers that aren't a complete fit your support costs drop dramatically.
In order to have a chance at fighting Craigslist, these services need to start hyperlocal first. There's nothing worse than going to one of these sites, entering your zip code and finding there's no listings.

It's much easier to market to a small geographic area first. One great tip I heard in a Mixergy podcast came from the founder of GrubWithUs. To get started, they printed 10,000 flyers and went around stuffing them into the free daily papers in their hometown.

Once you get going in a small area, then you can expand out. This is the only way to win against craigslist.
Reduce friction whenever possible. Allow the user to place an order before the confirmation, but limit the account until the user does. Also show an alert after a successful order that an email confirmation is being sent out and an option to resend it.
Yeah, the point of fizzbuzz is that it's an extremely simple test that demonstrates basic competence, nothing more.

I have a CS degree and took a bunch of math courses and did lots of proofs, but now (several years later) I'd struggle to write any of the suggested proofs.
My suggestion: Prove the infinitude of prime numbers.
The Monty Hall problem? Like other suggestions, too many people might be able to recreate it from memory.
> * Find three whole numbers in arithmetic progression whose product is a prime.

I don't think there's an agreed upon definition of what a "whole number" is. Then again, if you're just looking for how someone reacts to such a question, I suppose it's fine, if a bit silly.
I liked that point. Didn't really think about how much the article handled stuff as "girls things" and "boys things" until this comment.
Hungarian Olympic Online blog - watch London 2012
I have been using this when interviewing people with math degrees:

Two players play a game with a single six-sided die. The player that starts can only win by rolling a 1. If he or she doesn't win, the other player gets to roll; he or she can only win by rolling a 6. The game continues until one player wins. What's the probability the first player wins (eventually)?
Seriously, honestly, the majority of women could not be stuffed about celebrity wedding dresses. Sure, more women are into it than men, I won't argue about that. But I'll be damned if 'caring about celebrity wedding dresses' is classed as a 'women's issue', because, frankly, it's not. No more than 'caring about racing cars' are a 'men's issue', and most men get through life not thinking about them much, and just as many find them boring as interesting. If I was forbidden to talk about racing at work, I wouldn't go around yawping about how my boss had problems with "men's issues". It's not a women's issue, it's a fashion issue.

Note that I'm talking about real, actual men and women here; not the stereotypes that folks have in their head, but the actual people they want to do editorial work.

A better example: What about guns? The gender balance when it comes to vocal, visible people who like guns is heavily skewed towards males, but people don't call out gun control advocates as causing trouble for 'men's issues', or 'trying to silence men'.

The issue here is less 'geeks hate women, and so women's articles suffer in wikipedia', and more 'geeks care less about subjects outside their bailiwick, like fashion, and so those articles suffer in wikipedia'. The question is really 'how do we loosen the reins of the geeks a little', not 'there's not enough Genital Type V amongst our editors'.
You can get a iPhone app subscription to Britannica for a few $/mo. I have found Britannica to be excruciatingly better written and more comprehensive on their in-depth articles than Wikipedia. Things that aren't in the nerd enclave are covered, and well. I would never donate to Wikipedia as it is today: I happily send money to Britannica.

There are too many structural problems with Wikipedia - documented over the last few years by various angry bloggers - for me to feel OK with Wikipedia. Some of the content - good. The community & rules - blech. c2 is a better wiki. :-)
I understand that notability is not a simple rule but the result of countless debates and arbitrations that resemble a system of common law. Still, I think it is very unfortunate that a new contributor often needs to win an argument with a deletionist as soon as he writes a new article for the first time. That's like requiring every new business to win a nasty lawsuit (or jump through similarly onerous hoops) before they can actually sell anything. The result of the former is a precipitous drop in the number of new contributors and the further consolidation of editorial power in the hands of existing contributors. The result of the latter, which we often see in markets with government-approved quasi-monopolies like health-care supplies and payment processing, is stifled innovation.

> Maybe we should just opt for a simpler system and resign to the fact that the end result will be worse.

How do you know that the result will be worse? What do you even mean by worse? One of the symptoms of an unhealthy monopoly is that the established powers refuse to experiment, lest they lose their dominant position. Attempts to depart from the status quo are met with alarmism and doomsday scenarios, and existing rules and procedures get romanticized to absurd ends. When a community is ailing, its cherished processes should be the first to be questioned. Deletionists might have had a noble purpose when they began their crusade a few years ago, but now that they wield an enormous amount of power over other contributors, I cannot think of them except as part of a self-perpetuating unhealthy monopoly over editorial power.

Rules like "Thou shalt not put up ads here" and "Thou shalt use proper citations", even if no less complicated to apply in the real world, at least articulate clear ideals that people can understand, and provide concrete guidelines that new contributors can follow. The less abstract the rules are, the less room there is for abuse.
It's a new currency, it would be illogical to assume that the price of bitcoins will be wildly irratic as it catches on. The one thing I know about bitcoins is that I don't know what they'll do. The volatility makes bitcoin trading attractive to me, also, you can only lose what you put in, the trading costs are ridiculously low, and I started my account with $100 bucks. Initially I lost value but I just waited it out and turned $100 into $130. That's a huge return in less than a year. Obviously this is more of an exercise, I wouldn't get stupid with how much I put into bitcoins, the whole thing could collapse tomorrow.
To take as much from FizzBuzz as possible - how about "What is the sum of all integers between 1 and 1000 that are divisble by 3 or 5?"

It's simple to figure out with pen and paper but the goal is to just confirm a basic level of competence.
Most likely your Ubuntu uses PAE, and Windows does not. NT kernel certainly supports PAE, but likely MS has disabled it in client systems for some reason.
That's my guts feeling as well.

IMO it splits the difficulty into two steps (starting to use the tool, then sign-up up / paying).

For a product that is easy to get started, it seems to make sense.

Thanks for your feedback!
Impressive return - thanks!
Oh my gosh! there must have been highly trained agents pretending to be managers at my old Fortune 100 job! (I always knew it was impossible they where that incompetent!)
jk jk :)
You are the reason apple gets away with this stuff. They have brainwashed people into thinking apple and nothing else will compete. Thats when apple has fallin off a cliff since steve left anyways.
Crockford on Coffeescript
Ah, ok, that makes more sense. I guess I assumed that they only showed the students holding the items after trying, not their actual effort. Now I'm a bit depressed.
What’s the best way to manage a team of remote software engineers?
Actually, it's been known for quite awhile that there's a factor of 2 to 3 times in productivity. That's not really marginal. Talent far outstrips that, though.
In what sense are they to be equivalent?

In any case I'm going to suggest this:

Q. Give two different proofs of the fundamental theorem of algebra.
thanks! for this post...really a nice insight.
That's exactly my point. In the case of our app (https://www.wisecashhq.com/), it would be totally doable, but would still require a bit of work to create two sub-apps based on the same core features, and handle the scaling differently (I don't want the demo traffic to interfere with my actual, paying customers).

Thanks for you link as well!
Productivity is productivity, just like "Power is power."

http://www.youtube.com/watch?v=ifaRhL95HUM

http://www.giantitp.com/forums/showthread.php?p=13003072
Ask HN: Should we (the community) build an HN alternative? 
There are tons of interesting feature requests as well as incredibly needed bug fixes listed in the "features you'd like" thread at http://news.ycombinator.com/item?id=363. IMHO and with all due respect, by now it's pretty clear that PG is not willing/able to address them, even the most glaring ones (cough unknown or expired link).

Having a community built, opensource alternative to HN would allow us to implement the features we want and could be a pretty fun experiment.

I know HN is itself opensource, but it's written in an obscure language and, as far as I know, does not accept 3rd party contributions, so it pretty much negates the main advantages of an opensource project.

This new project would be based on these principles, which (IMHO) HN fails to address:

- Opensource code, built using a mainstream language/framework, so contributing is not just easy, but actually encouraged.

- Community transparency: Everything is public, including upvotes and downvotes to stories and comments.

- Moderation transparency: Having moderators which modify the titles, etc… is fine and sometimes a must. You just have to show a log somewhere attached to the story where users can see which changes were made and by whom.

- Have a nice and complete REST API, so 3rd parties and mobile/desktop applications can properly interact with the site without resorting to hacks or scrapping.

I would gladly spend a week writing the MVP and opensourcing it, to kickstart the process. So, what does the HN community think about it?
Using this as a justification not to have good tools ("What's wrong with you? Suffering worked great last time") is bogus logic; there's no reason not to have good tools. The other side of the coin, NOT doing something because you don't have good tools yet, is equally poisonous.

This middle ground approach is probably best.

PG writes about tools and their importance in "Beating the Averages": http://paulgraham.com/avg.html .
> the total number of people that paid at the end of the trial period went up significantly.

That's what I would have suspected as well. Weeding out the users that are not a good fit is very interesting indeed!

I suspect too that asking for CC info straight after the demo would be less of a repellent, once the visitor has actually tried the app (and it will probably lead to less chargeback, too).
Interesting - can you give me two possible plausible definitions of "whole number"?
Or apply Bayes' theorem to a real world problem http://yudkowsky.net/rational/bayes/
Introducing Programming to Preschoolers
Exactly. Github (and every other flavor of the time) is an example of the problem. Not the solution.
Explain and demonstrate the use of Taylor series. Quite a bit easier than many of the other suggestions below, and will weed out total idiots. Kind of like asking a supposed programmer to explain a "for" loop.
Perhaps it shouldn't be solving one problem, but maybe explaining a base concept in a field most mathematicians know, and how it's important - since there's no one right answer, it would also show their experience and so forth - most people probably know what they are, but the more experienced will be able to talk for quite a while. iono, Cauchy sequences, maybe. or groups
Pattern Matching: Flow Control Made Beautiful
That really cool stuff nestled deep in a propiratary binary, Odds are its not really that neat or cool.

Well, cool could be defined to include popularity. A lot of ideas were great before they were cool. There are a lot of great ideas out there now that aren't cool.
Scarcely requires math, seems only to require arithmetic.
A side note, how do you go through a reference and lift all the information from it while avoiding simply paraphrasing it? Or are you using it as a starting point then finding more sources on these mayors?
Given how I have architectured the app (modular enough) and thanks to DotCloud (for scaling up the demo without much setup), that's definitely something I could deploy in a week. Thanks!
I accept that smart people are using C++, Perl, and even PHP, to produce amazing, finely crafted software.

I do not accept that they are making it any easier on themselves by this choice of language.
Prove that the inverse of any element in a group G is unique.

Edit: If this is too easy, prove that g in G, g -> g^2 is a homomorphism iff G is abelian.

Note: I am not a mathematician.
Anyone else thinking about Diaspora as soon as he mentioned Kickstarter?

Grandiose vision, but going to war with Twitter today is as foolish as trying to take on Facebook.

You're not going to attract a mainstream audience and gain serious critical mass just because you're an open platform and developer-friendly. In the case of SourceForge/GitHub, it was different because the demographic is entirely developers. Not so with social networks or media companies of any kind, the audience is mainstream, that means college students, celebrities, high school girls, etc.

"Every battle is won before it is ever fought" (Sun Tzu) -- learn from Diaspora's failure, don't repeat it.
Sounds like free advertising for Samsung. If the products are good enough that Apple is playing dirty tricks to remove them to the market, maybe I need to reconsider buying a new iPhone when my contract runs out this fall.
Hacker News, 4chan(No, really.), and some good subreddits.
Working with/for someone isn't programming, it's business relations, and thinking otherwise hurts both parties. It is a nuanced difference, though.
New Social Network? Find what your local people are doing? It's a BETA site.
Or the "original communicators." When you start to read the masters of every field, you realize they are in some sort of a conversation that spans centuries and you get to participate. One problem with this approach is these are dead teachers so no question & answer session for you, and usually the material is hard to comprehend at first. That is exactly what you need it, a material that elevates you, something that pushes you from understanding less to understanding more. Lastly, during this exercise you will find amazingly that there are really only a few original teachers and that most of what we read today are simply digest of what was originally written and discovered by a handful of experts. So it is probably in your best interest to take it straight from the horse's mouth.

Yes, I am repeating Adler's How To Read.
Hmm. Did you see that I already mentioned that in the question?
I think the 'problem' was that you need two wires to close the circuit.
Don't rewrite, refactor!
It's the same almost all of the time, but some searches with colons will be run through the URL path instead because it thinks you meant http://
The only way to know for sure is split testing.

On the one hand, you build a bigger mailing list + extra friction.

On the other, smaller mailing list, but more users get to try your service.

I recommend a split test.
> Something told me to stop the car and go in.

I am a rationalist and have no truck in telepathy, crystals, or other such related craziness. Coincidence and the law of large numbers explains everything.

...but once in a blue moon I hear a story like this and do have a niggling thought: maybe the universe is much deeper and weirder than we think. And/or the grad students who are running the simulation we all exist in like to play tricks on us from time to time. ;-)
XBMC For Android
This is a great question. Why don't you set up an A/B test?

Yes, I know, you're hoping someone else will know the answer. But if you don't develop the habit of testing, you won't be in the habit of testing, and you won't be testing things that are unique to your business.

This is what patio11 keeps on complaining about. When there is a discussion of A/B testing, everyone says how great it is. But over 90% of you simply aren't doing it. And in a thread like this you can see that people really aren't doing it.
When you create an MVP you shouldn't be thinking about the products success in terms of it's sales. An MVP is basically an experiment, you should be looking at feedback you're getting from it and how that feedback can be used to improve the product.

Do people like the product's goal but not a certain aspect of it? Great! Now go change that aspect and see what they think now. Repeat and repeat until the product is financial success.

If you're not getting sales that's fine, focus on just getting people more people to try a free account. Maybe change the homepage around one day, see how that affects the rate of sign ups. Keep experimenting and improving.
This question comes almost at the time for me. A few weeks ago, i was wondering the same question for my first startup, an online task manager, namely eekip. In the end i thought, there are so many task management software out there, and each single person likes it different way, so I'd better give people a look inside to see if this is suitable for them. And hell, it wouldn't be that much of a pain to code it up anyway. I ended up spending about 3 days straight to get it done. What happens is users can try the demo account with only 1 click, and once logged in the demo acc, i tried to present the best stuff to the user, just so that user wouldnt be walking away and say : "Move along, nothing to see. Just another dumb task management software!". If you're curious, you can see how i pulled it together at http://eekip.com (still in alpha)
Do you really imagine that someone trying to set up mandatory EU-wide health insurance in the EU would be considered "conservative" in Europe? Notwithstanding that "conservative" means very different things, depending on which part of Europe you are in.

The idea that there is an objective left-right scale, and that the US is skewed far right compared to the rest of the world is a myth.

Personally, I tend to the definitions: left - pretends to be caring; right - pretends to be competent.
These Spinning GIFs Are Just Great
Do you mean like how erlang, haskell and ocaml can be run on bare Xen slices?

http://corp.galois.com/blog/2010/11/30/galois-releases-the-h...

http://halvm.org/wiki/

http://anil.recoil.org/papers/2010-hotcloud-lamp.pdf

http://erlangonxen.org/
My macbook bricked while I was on vacation, allowing me to actually read a bunch of the books I always bring along but never get around to...
Maybe I'm just a sucker for group theory but that strikes me as too trivial for any mathematician.

In that same vein, I'd suggest proving that a group G is abelian if and only if (ab)^2 = a^2.b^2, where a, b are in G.

It's not as straightforward as your question in the sense that proving it requires a little idea that you have to come up with.
I'm not sure they lack such understanding. Isn't this what psychologists call cognitive bias, or something like that? I believe there was a thread here on HK about it, a study showing that people often do irrational things because they assume they know everything. You know? People just think "geez, that is easy..." and rush to answear the first thing that comes to mind, just to discover that they missed the details and feel really stupid :P
This is a great data point.

Did you run it as an A/B test to be sure that the eventual rise in people paying wasn't because of some other change that you made which you're not thinking about?
I'm confused. Coffeescript compiles to JavaScript which usually runs in a vm with a jit.
Uhh.. Microsoft security essentials?
As a mathematician I'll be interested in knowing why you ask that question to people with math degrees.

What information does that give to you as an interviewer?
I believe there are opportunities for many Githubs For {insert_industry}
Did you A/B test? Could there have been another reason that traffic tripled?
Apple should focus on competing on the quality of THEIR product.

The other day, I stuck a spare SIM into a 1st gen iPhone 8GB running iOS 3.1.2. Even on EDGE, the thing smokes my iPhone 3GS on iOS 5.1.1 bringing up the Maps program using 3G at the same location. It's positively slick, responsive, and just beautiful.

Undoubtedly, there is a lot of bloat in both iOS and OS X now. My Macbook Pro running Lion is way slower than when it was running Snow Leopard, and the thing has an SSD! I've even disabled noatime and swap. That makes my machine faster, but it's still slower than it was.