The 2-second "Rule" - <AUTHOR> https://medium.com/design-startups/e7982d68de8c

<comment><USER3> > 2\. Social - the visitor has clicked a link, typically with accompanying > context from those in their network

And often the context is "That's cool", or "Foobaz widget upgraded!". And I click and have absolutely no idea what the website even does.

It happens more often than you might expect - especially with deep links. I'll go to the home page or a faq page first when that happens. And you'll be surprised how often neither of those give even the slightest clue what the site does.

<SARCASTIC>After all it's totally obvious to those who made the site! I mean how could anyone not know what this site does? I spend hours on it every day.</SARCASTIC>

There are an astonishing number of people who have no "Theory of mind" - <USER2> simply are unable to put themself in the position of someone else and try to understand what the other person doesn't know.

<comment><USER4> This is a huge complaint of mine about emails I get from various startups: 'Hey, check it out, we just launched version 2 of our awesome product, X!'

Me: 'I don't remember what product X does, so I'm just going to delete this email.'

I wish more emails would begin with: "Foo is the world's best way to Bar and Baz. You're receiving this email because you joined our service, Foo, in March 2013."

It doesn't matter if _you_ know what your service does. Assume I have _absolutely no idea_ what your service does, even though I signed up for it. Because I don't have any idea what it does.

<comment><USER5> Except that if someone claims to be the best in something I'll also trash spam the email. There are many other ways to spin a tagline.

</comment></comment></comment><comment><USER6> _Are most of your site's visitors arriving with zero context of who you are and what you do? How is that even possible?_

Because it was linked from HN, and the title got set to the page's title, and all I know is that there is a new version of some tool, but I don't know

1\. what this tool does,

2\. why I want what this tool does,

3\. similar tools that are out there (if you don't know what these are, you are making me look them up), and

4\. the differences you have from the things in group 3 that say this is the right tool for some particular circumstance.

</comment><comment><USER7> Attempting to define a "rule" in this is what the title should imply is the failure, but it doesn't seem to take that to heart.

What you should be avoiding is having users reach your home page and saying to themselves, "Where am I?" Even if they are random hits -- which happens, and often -- your root page, the one people come in on who aren't going anywhere specific, should make it clear what you do or are, or at least avoid making it unclear.

<comment><USER8> > What you should be avoiding is having users reach your home page and saying > to themselves, "Where am I?"

Strongly agree.

The article itself is an interesting example. "Where am I?" I asked. Apparently on the blog of one Patrick Woods. Personal blog or company blog? Dunno. Eventually, I made it to the Medium homepage. Never heard of Medium. What is it? Time passes ... and I determine that it's sort of a cross between a group blog, Twitter without the character limit, and Reddit.

That took me a couple of minutes. Yes, I know, I could have simply gone to the homepage through the "M" menu, and then clicked on the little "Learn more" link in the lower-left-hand corner, but _I didn't know I was supposed to do that_.

There is a lesson here. FTA:

> Are most of your site's visitors arriving with zero context of who you are > and what you do? How is that even possible?

Most? Maybe, maybe not. But _some_ certainly. I arrived on Medium through a process entirely orthogonal to the purpose of the site: reading an article relevant to startups, chosen from a list of links of interest to hackers.

</comment></comment><comment><USER9> Studies show that it takes less than a second for visitors to determine - based on appearances - whether or not your site will bring them value. The Nielson Norman Group says that in addition to this, you only have ten seconds to provide written-proof of that value:

> the first 10 seconds of the page visit are critical for users' decision to > stay or leave. The probability of leaving is very high during these first > few seconds because users are extremely skeptical, having suffered countless > poorly designed Web pages in the past. People know that most Web pages are > useless, and they behave accordingly to avoid wasting more time than > absolutely necessary on bad pages.

> To gain several minutes of user attention, you must clearly communicate your > value proposition within 10 seconds.

> [http://www.nngroup.com/articles/how-long-do-users-stay-on- > we...](http://www.nngroup.com/articles/how-long-do-users-stay-on-web-pages/)

The author is assuming a few things: (a) that most visitors to your site are there because they intended to be and don't need their hand held to get to the next step, (b) that there is only one 'next step' to send them to, and (c) that your short description is a list of bullet-points as opposed to a sentence or two.

For one, I don't think we can assume the intent and understanding of most users. I visit more sites daily that I don't have a clue about than those that I do, but maybe I'm a small percentage. Secondly, depending on the product, I think bullet points can be just as effective as a short blurb (especially if you have a tagline that does a good job summing things up). Pinboard (<http://pinboard.in/>) is a great example of this.

</comment><comment><USER5> He's got a point here. You shouldn't have a "we do this and that" tagline displayed in 30pt orange on your home page.

However the HN has a point too, but a part is missing: I should be able to tell what you do in less than 2s _if I need to know_.

So the tagline needs to be explicit but it can be a small font incrustation beside the logo.

</comment><comment><USER10> It's true that as a visitor of a website I will often already have an idea of what it is. But when I visit it, the first thing I want to know is whether that was correct.

Yes, all those in-channels imply context - but that context is often very different from place to place. We approach links we found on google differently than ads or links we found on social media and the information that's already given will differ. A simple description, or more broadly, _anything_ that quickly makes clear what you do, isn't primarily for informing random visitors who had no idea, but for quickly getting everyone on the same page no matter where they come from.

I'm all for explaining what you do in such a way that it is also helpful in taking people that already know to the next step - but please, don't skip it entirely.

</comment><comment><USER11> Same is true for sales-type emails, I'd say. All too often, the mistake is to "sell" the reader in the initial email. That only works if you're selling something incredibly compelling and easy to understand. Most startups don't have that. The goal, then, is more to pique interest; to make the reader want to learn more.

I've learned this lesson first hand more than once, unfortunately. If you make the entire sales argument in an initial email, then you have no chance to drive the conversation. You're giving the reader an opportunity to make a 0 or 1 decision before you even have the chance to explain a bit of the gray areas. Don't do that, if you can help it.

<comment><USER12> It's analogous to job ads that spend the first 500 words describing what the company is trying to do and how much foosball and dinners yadda yadda, the actual job details being haphazardly compiled at the bottom. Narcissistic business model syndrome.

</comment></comment><comment><USER13> I was searching for a tool for specific task so I googled some terms that I hoped would be relevant. I clicked on the first 10 links that looked promising into 10 new tabs. Then I looked through these tabs and rapidly closed the ones that at a quick glance didn't give any indication that they might be helpful in solving my problem.

It shouldn't be hard to tell me what problem you are trying to help me to solve, and how you do it differently than everyone else, using a sentence or screenshot or two.

If you can't do that, I suspect that your business model has some more serious problems.

</comment><comment><USER14> I clicked on the link expecting to see something about food dropped on the ground...

Then I noticed that the site doesn't scroll in my browser when using my keyboard.

That's when I hit Ctrl + w and posted this.

<comment><USER15> Fixed html element use (or abuse depending on one's prerogative) for the page background is the cause. Disabling them on the page with user css fixes it. I think they're mostly an anti-pattern and poor UX, but a lot of designers and developers love to use them these days, unfortunately.

Using this <http://pastie.org/7942978> with user css will disable them for you on any sites you encouter.

</comment></comment><comment><USER16> Why do sites like this deliberately break things? Even when the window has focus <SPACE> doesn't page down, breaking the way I work. Is there a reason? Or are they just out-of-touch with (some of) their readers?

</comment><comment><USER17> OT: great typography and design on this page.</comment>


What the Real Estate Pundit is doing next - <AUTHOR> http://www.realpundit.com/home/2014/what-real-estate-pundit-did-next-getagent

<comment><USER2> Would love any thoughts or comments on the notion of ranking real estate agents. Or what other data would be cool to include.

</comment><comment><USER3> Are you still in mourning or is it afternoon yet?</comment>


MapPLZ: Geo package for Go, Node, and Ruby - <AUTHOR> http://www.mapplz.com

<comment><USER2>
      mapstore.Add_Lat_Lng(40, -70)
      mapstore.Add_Lng_Lat(-70, 40)
      mapstore.Add_LatLng( []float64{ 40, -70 } )

Few minor gripes for the Go code; don't use underscores and don't provide method signatures for all arrangements of values, all you need is mapstore.AddLatLng(x, y)

<comment><AUTHOR> How can I differentiate the functions for adding {40, -70} and two parameters 40, -70? Both would be AddLatLng.

I've asked the Go community about this before, and the suggestion was to create a Location object with latitude and longitude. This is the type of specialized API that I am trying to avoid. A developer should be able to chuck their existing data at MapPLZ and get back a geo point.

<comment><USER2> User's responsibility:

mapstore.AddLatLng(ll[0], ll[1])

Or:

mapstore.Add([]float64) / mapstore.AddLatLngPair([]float64) // or some variation of

A lat/lon struct would also be good, removes validation of the float slice etc.</comment></comment></comment>


DeepDive – System that enables developers to analyze data on a deeper level - <AUTHOR> http://deepdive.stanford.edu/

<comment><USER2> This could be a huge value-add to the groups that have invested heavily in human-directed knowledge graph construction (e.g. Project Halo/Aristo at the Allen Institute for AI).

</comment><comment><USER3> kllj

</comment><comment><USER4> It's also being used to aid paleontology research: [http://fusion.net/story/30751/paleo-deep-dive-machine- learni...](http://fusion.net/story/30751/paleo-deep-dive-machine-learning/)

</comment><comment><USER5> I'm mostly interested in how much does it differ from what IBM Watson does. Does IBM only rely on probabilistic inference or does it do other data mining as well?

<comment><USER6> It's (very) roughly comparable to parts of it.

Firstly: IBM is increasingly using the Watson brand for things that don't appear directly related to the Jeopardy winning system (eg, Watson Analytics). When I talk about Watson here I mean the Question Answering (QA) system.

At a very high level DeepDive consists of a Knowledge Graph construction tool, and a probabilistic querying tool. Compared to Watson it is missing a natural language question parsing tool, and any way of dealing with questions that aren't in the KG.

Watson has (very strong) natural language understanding for multi-claused questions, and the Jeopardy version can do things like understand puns. Deepdive doesn't have anything comparable. In the open source space, the closest thing I'm aware of is SEMPRE[1][2].

Watson also has a evidence scoring module, and my understanding is that this can work against unstructured data. Deepdive doesn't have this, and instead relies on probabilistic inference. This is an excellent approach, but relies on doing content extraction first (ie, extract entities and relationships from text and/or other sources). The Microsoft Probase[3] group has published lots in this area.

[1] [http://www- nlp.stanford.edu/joberant/homepage_files/publicat...](http://www- nlp.stanford.edu/joberant/homepage_files/publications/ACL14.pdf)

[2] [https://github.com/percyliang/sempre](https://github.com/percyliang/sempre)

[3] [http://research.microsoft.com/en- us/projects/probase/](http://research.microsoft.com/en-us/projects/probase/)

</comment></comment><comment><USER7> I am wondering what a ballpark figure would be how long it would take to set up an instance of this for a given scientific field for example. Days? Months? Years? I fear it is probably the latter.

<comment><USER8> I've sat in on Chris' class at Stanford.

I think the answer is probably closer to weeks to months if working with field experts, depending on how deep you want to go.

The core of it is open source.

I think the most exciting thing about it is it brings more sophisticated computation to the more qualitative sciences.

<comment><USER9> What about for just a smallish single machine corpus of document (1000)?

<comment><USER6> The size of the corpus isn't the issue (apart from processing time of course).

The key issue in estimating how big a job it is is how complex your entity extraction and inference rulesets are.

</comment></comment></comment></comment><comment><USER6> It does probabilistic inference![1]

So many open source "Knowledge Graph"-y type projects concentrate on building them like databases, with a query language that assumes the data in them is correct. You see this in things like Freebase, DBPedia and Wikidata, where they typically end up in a triple store and you query using SPARQL.

This isn't how the real world works, and there isn't a lot of publicly available software that takes this into account. There aren't even than many papers about it (the Microsoft Probase paper is one, and there is work from Florida University(?) about using Markov chains to reason while taking probabilities into about).

I'm excited to take a look at this.

[1] [http://deepdive.stanford.edu/doc/general/inference.html](http://deepdive.stanford.edu/doc/general/inference.html)

<comment><USER10> Aside from the work on probabilistic inference, there is also many papers on "probabilistic databases" in the last 10 years (Chris did his PhD on that topic). That work has looked at SQL-style query processing over "uncertain"/"probabilistic" data.

These were some of the major projects: [https://homes.cs.washington.edu/~suciu/project- mystiq.html](https://homes.cs.washington.edu/~suciu/project-mystiq.html), [http://maybms.sourceforge.net/](http://maybms.sourceforge.net/), [http://infolab.stanford.edu/trio/](http://infolab.stanford.edu/trio/), [http://www.cs.umd.edu/~amol/PrDB/](http://www.cs.umd.edu/~amol/PrDB/), [http://dl.acm.org/citation.cfm?id=1376686](http://dl.acm.org/citation.cfm?id=1376686).

<comment><USER6> This is a fair point. In a similar vein there is also BayesDB [http://probcomp.csail.mit.edu/bayesdb/](http://probcomp.csail.mit.edu/bayesdb/)

<comment><USER11> An HDFS oriented one (with SQL style queries):

[https://www.cs.berkeley.edu/~sameerag/blinkdb_eurosys13.pdf](https://www.cs.berkeley.edu/~sameerag/blinkdb_eurosys13.pdf)

[https://github.com/sameeragarwal/blinkdb](https://github.com/sameeragarwal/blinkdb)

<comment><USER6> Is it?

I thought BlinkDB was data warehousing on hdfs? I dont see any mention of inference-like features in the docs?

<comment><USER10> It's not similar. BlinkDB builds upon the work on sampling-driven approximate SQL query processing (an early project in that space was AQUA@Bell Labs), and extends it to cloud/HDFS setting.

Although some terms come up in both places (e.g., confidence bounds, noise, etc), BlinkDB and probabilistic databases are fundamentally different from each other (I have worked on both topics).</comment></comment></comment></comment></comment></comment>


Release 0.1 of CFFI - <AUTHOR> http://morepypy.blogspot.co.uk/2012/06/release-01-of-cffi.html <comment><USER2> I tried to run the simple example and I get:

      >>> from cffi import FFI
      >>> ffi = FFI()
      >>> ffi.cdef("""
      ...     int printf(const char *format, ...);   // copy- pasted from the man page
      ... """)
      >>> C = ffi.dlopen(None)
      >>> arg = ffi.new("char[]", "world")
      >>> C.printf("hi there, %s!\n", arg);
      17

Python 2.7.3rc2

pycparser 2.07

libffi5/libffi-dev 3.0.10-3

Debian with 3.2.0-2-pae x86

<comment><USER3> Hmmm...

From man 3 printf: "These functions return the number of characters printed (not including the trailing `\0' used to end output to strings) or a negative value if an output error occurs". So the 17 makes sense, but where did the output go?!

</comment></comment><comment><USER4> There is already a C function interface for Common Lisp called CFFI: <http://common-lisp.net/project/cffi/>

<comment><USER5> I had the same thought.

A simple google search would have shown them that the acronym is already taken.

I am still unhappy with Google co-opting the word "Go" from an ancient and very popular Board Game. Atleast they have the excuse that the domains are different (One a board game and the other a programming language).

Two software projects which offer foreign function interface functionality from a higher level language to C with the same acronym? This is irresponsible.</comment></comment>


Hertz files for bankruptcy as the coronavirus pandemic crushes rental industry - <AUTHOR> https://www.businessinsider.com/hertz-filing-for-bankruptcy-as-early-as-this-weekend-report-2020-5 <comment><USER2> Discussion: [https://news.ycombinator.com/item?id=23279327](https://news.ycombinator.com/item?id=23279327)</comment>


Model S Fire - <AUTHOR> http://www.teslamotors.com/blog/model-s-fire <comment><USER2> I agree this isn't as big of a deal as the stockmarket may imply, but this line bothers me:

"That equates to 1 vehicle fire for every 20 million miles driven, compared to 1 fire in over 100 million miles for Tesla. This means you are 5 times more likely to experience a fire in a conventional gasoline car than a Tesla!"

Americans drive an aggregate of 3 _trillion_ miles every year, while Tesla drivers have done 100 million (and they don't cite this number; are they including test drives?). That's well over an order of magnitude difference. Plus, the average Tesla driver is currently probably a superior driver (if for no other reason than they have a brand new expensive car) and has taken better care of their car (since it's within 2-3 years old, tops). In theory, Teslas will eventually become more mainstream over the years -- resold, price drops, lower-end models, etc.

Again, I don't think their conclusion about Teslas being safer overall is wrong. However, their conclusion of the likelihood of a Tesla catching on fire seems off, and the exclamation mark makes this press release seem glib.

<comment><USER3> > _Plus, the average Tesla driver is currently probably a superior driver_

I can play the conjecture game too.

The average Tesla driver is probably a worse driver than the average gas- powered car driver. Why? Because they have the disposable income to purchase a Tesla, which means they're probably less careful with their possessions (as they can presumably afford to replace them), plus the Model S is a sports car so they're probably driving faster and more carefree than your average person.

Not that I really believe this, but come on, your argument is completely made up.

<comment><USER4> I would counter with, "How dare you assume that all Tesla drivers have disposable income to throw around". I happen to be close to buying one and know a few other owners who are average middleish class people who normally would have bought a porsche or a tesla. I work in tech and as a result am paid pretty decent. Do I have disposable money (or my friends) to buy a Tesla Model S? No! However, given where I live and where I want to drive + the recharging stations, Tesla is a good option for me.

Do not assume just because someone is able to get enough money to buy something expensive,that they have tons of money. By that same logic, anyone who is able to buy a home is clearly flush with cash and able to throw it all around. Completely ridiculous.

<comment><USER5> The average yearly income in the US is $43,000. The base price of a Model S is $63,000. There is simply no way to afford a Tesla as an average, middle-class laborer without making massive tradeoffs in quality of life elsewhere. If you can afford a car that costs such an absurd amount of money, you are either living in squalor to afford it or you are not middle class. It's tiring to see people who are obviously the beneficiaries of economic privilege pretend as though they are "average." You are not, and to assert that you are demonstrates a fundamental ignorance about the difficulties that "average" people face.

As for the house argument, you and I both know that the two are totally incomparable. Putting a roof on your head is a much bigger priority than buying an electric supercar. People need to pay for shelter. They generally can't afford to pay a lot for luxury cars. If you argument is true, why isn't everyone buying $63,000 cars? (Not to mention the millions of people who can't even afford homes.)

Your posts demonstrates everything that is wrong with class stratification in America. I don't think you or your friends who elected to choose Teslas over Porches know what it means to be "average."

<comment><USER6> I know a local gardener/landscaper laborer in the SF bay area who makes $25 an hour in cash by working after hours. If a Tesla lease is $600 a month (the website says that, but it's based on some assumptions including where you live), he would have to work about five hours a week extra to afford a Model S.

That means this SF bay area laborer must give up a Saturday or Sunday afternoon every week, but it's hardly impossible "to afford" or a "massive tradeoff in quality of life." On the other hand, it's challenging to haul a few thousand pounds of mulch in a Tesla, I expect.

<comment><USER7> Ok, so if you commit tax evasion in an all-cash business, you too can work just an extra 1/2 week every month to lease a tesla, after factoring in the tax breaks EXCEPT... from my 5 minutes of research, the $7500 tax credit is not a refundable credit so in his all cash business if he's not at least paying $7500 a year in federal income taxes, he won't get the full benefit of that credit.

Oh, and the $600/mo assumes a $7100 down payment, which needless to say is far more than the average down payment on a car and is really more like what the average american puts down on a HOUSE. In other words: c'mon.

Not to mention the opportunity cost of that money. If you're making $25/hr in SF you do not have a high standard of living, especially when compared to your neighbors which, studies have shown, is exactly how we measure our own financial happiness.

<comment><USER6> In this case, the SF bay area fellow I know works five days a week for a landscape/gardening company and pays taxes on that income. ($25/hour cash is additional off-the-books income.) And, contrary to your research, California has a $10,000 incentive.

Though you're right about the down payment, so let's assume it will be a used Tesla and therefore cheaper. And you're right about the relative comparison point. But these were rough numbers, remember, and not intended to be a detailed argument as much as a refutation of the impossible "to afford" claim above.

</comment></comment></comment></comment></comment></comment></comment><comment><USER8> My boat's hull happens to be made of 1/4 inch metal plate (6mm) which is apparently the same as the protected underside of a Tesla. I've hit a concrete block, gone aground a few times and generally have a bit of excperiencing with impacting hard immovable objects with a vehicle protected by a 1/4 inch metal plate.

It takes a LOT of force to pierce 1/4 inch plate. My boat weighs 12 tons, and it hardly has a dent from the collissions I and previous owners have been in.

<comment><USER9> your point being?

<comment><USER8> that if a tesla has a 1/4 inch protective plate seperating the batteries from the road it's a safe vehicle indeed.

I was simply sharing my personal experience with ramming 1/4 inch plated vehicles into hard immovable objects to give some perspective as to what kind of strength we're talking about.

</comment></comment></comment><comment><USER10> Tesla's write-ups on their blog are the most informative reports I've seen written by a company about their own product. It's awesome to see this kind of transparency as opposed just a copy-paste statement like "Tesla is investigating the event."

</comment><comment><USER11> I think the write-up is pretty good.

I would only point that 25 tons of force, isn't really a lot - I mean, the small jack that you use to lift your car can be a 5 or 6 ton device.

You have a vehicle traveling a decent rate of speed, for it to strike or run over anything at all will involve tons of force.

Neat explanation of the sort of math involved, with both SI and US units [http://hyperphysics.phy- astr.gsu.edu/hbase/carcr.html](http://hyperphysics.phy- astr.gsu.edu/hbase/carcr.html) . In the example, a car going 30 mph (50km/h) striking a tree will hit with about 48 tons of force.

<comment><USER12> > I would only point that 25 tons of force, isn't really a lot - I mean, the > small jack that you use to lift your car can be a 5 or 6 ton device.

It's not clear to me why you'd say it's not a lot of force while making the comparison to a jack. Take a jack and use it under the wrong spot on a vehicle and you might get a pretty painful display of vehicle penetration, which is what we're really talking about here.

<comment><USER13> ....yet the jack produces 1/5th the amount of force.

Just to put it into explicit perspective.

</comment></comment></comment><comment><USER14> It looks like they're backing off the claim that the fire was contained to only one cell. It's unclear, but if the fire were contained to only one cell, it's likely they would mention it:

"A fire caused by the impact began in the front battery module – the battery pack has a total of 16 modules – but was contained to the front _section_ of the car by internal firewalls within the pack."

If the fire was able to jump cells, does this make the battery pack "fundamentally unsound", as Elon has described the Boeing battery? Not necessarily. However, merely puncturing the gas tank of a ICE car in this way is not guaranteed to set the gasoline on fire. The ignition temperature of gasoline is over 500 F and the gas tank itself is plastic, most likely. Gasoline vapor is explosive, but the car was traveling fairly rapidly and a there's a fair amount of wind to dispel vapor. The ignition source would have to be heat from the metal of the debris self-striking metal of the debris, or though both layers of plastic to the auto frame itself, and that spark would have to find some gasoline, which is pooled at the bottom of the tank and not near the top. I suppose it's possible. Car crashes do produce burning gasoline, though usually it's a very severe crash that mixes gas vapor with the heat of the engine.

<comment><USER15> _within the pac_

This is worth noting. The fire did not stop and kept reignighting. The FD had to flip the car on its side and physically gain access by cutting the car up, to put the fire out. Under this scenario, it seems dubious that compartmentalization would be sufficient. Thermal conductivity at some stage would overcome the situation.

Also, you are right to highlight that petrol fuel systems are a cause only on a tiny minority of real-life auto accident related fires (~2%). The safety of petrol engines is actually quite high in this regards (counter-intuitive, perhaps). Plastic has the ability to deform rather than crack (flexibil vs brittle) and also the position of the fuel cells is much more protected. Think about the debris from front-tires -- much more likely to hit the undercarriage (where the Tesla battery is) than behind the rear axel (where many tanks are). Debris hit by the rear tires of course exits behidnd the car in either scenario. This setup is obviously not by chance. The Li Ion battery is probably low for COG reasons and fore-aft weight distribution. Li ION is much heavier than petrol.

</comment></comment><comment><USER16> Question: Is it really that unusual to have 25 tons of force applied to a point of the underside of the car in an accident? Does anyone know?

My conjecture: The Model S is a heavy car. Hit something pokey at speed and you've got an awful lot of forces channeled to a point.

I also thought it a bit much that Musk tried to compare this to severing "fuel supply lines" in a gas car. The likelihood of a 3 inch puncture severing a fuel line or entering the gas tank is _vastly_ lower than compromising a battery pack that runs the length of the underside of the car.

The Tesla's underbelly vulnerability zone is vastly larger than fuel tanks and lines.. and a punctured battery doesn't need an ignition source to start a fire, either.

<comment><USER17> Looking At some pictures and diagrams of the Model S battery pack, yes, it does look to be about twice as large as the average fuel tank. HOWEVER, that leaves out some really interesting things to note.

First of all, most automotive gas tanks are made out of ~1/8" HDPE. While it has decent cut and abrasion resistance, it's of virtually no use when trying to combat punctures and is also pretty flimsy, leading to deformation and possible cracking during an accident.

While, yes, a punctured battery pack is guaranteed to ignite while a gas tank is not, that is also the _only_ way for the pack to ignite. An object has to physically pass through the battery pack, while a gas tank could potentially start a fire if it cracks and starts leaking. There's a reason why you're supposed to try to get out your car as quickly as possible in case of a crash: fuel leaks very easily. In comparison, batteries are much more impact resistant due to their more solid state nature.

Also, it seems that whatever struck the car seemed to hit under or very close to where the front passengers sit. Had that armored battery pack not been there, there's a very real possibility that the driver would have been impaled. With that in mind, it should be pretty clear that this was a freak accident and not really representative of the average car crash.

</comment></comment><comment><USER18> Is Elon's claim, "the effective combustion potential is only about 1% that of the fuel in a comparable gasoline sedan", accurate?

AFAIK, all the Lithium Ion Battery electrolytes are flammable (they are pressurized in the battery container too). Depending on the chemistry of the Lithium-ion battery that Model S uses, some (I.E. LFP) are safer than the others, but still, 1% potential?

EVs like Chevy Volt, Fisker Karma and even Boeing 787 Dreamliner and UPS/FedEx freight flights had been caught Lithium fires in air before.

<comment><USER19> It's a 85kWh battery ([http://en.wikipedia.org/wiki/Tesla_Model_S#Specifications](http://en.wikipedia.org/wiki/Tesla_Model_S#Specifications)).

Gasoline is about 12kWh/kg or 9kWh/l ([http://en.wikipedia.org/wiki/Gasoline#Energy_content](http://en.wikipedia.org/wiki/Gasoline#Energy_content))

So, that 85kWh battery, when driving an engine, is equivalent to about 10 liters of gasoline. I guess that's more or less what could get released in a fire (corrections welcome; I don't know what kind of factor that 'effective' could introduce)

If that logic stands, to get at 1%, the typical car would have to have 1000 liters of gasoline on board (for the metric impaired: that's over 250 US gallons/over 200 imperial gallons). That, clearly, is unrealistic.

Elon may have knowledge of the loading state of the battery, but if so, I think he should have mentioned that. Gasoline tanks aren't 100% full all the time, either.

<comment><USER20> > Gasoline tanks aren't 100% full all the time, either.

The less gas a tank has, the more dangerous it could be. It's a common mistake to think a close to empty tank of gasoline is safer than a full one when the reverse may be true because of the fumes.

For example:

[http://www.commerce.wa.gov.au/worksafe/content/safety_topics...](http://www.commerce.wa.gov.au/worksafe/content/safety_topics/hazardous_substances/Additional_resources/Empty_drums_- _potential_bombs.html)

<comment><USER21> I'm not convinced of that. If you are worried about the tank going "pop", then a mostly empty gas tank would indeed be more dangerous. _However_ I think the more typical concern is the tank being punctured, leaking, then the leaking gas burning rather than exploding.

So basically if you want it to explode hollywood style, then you need gas vapors, but if you want a very bad car fire, then you need lots of gas.

<comment><USER22> it isn't much of a data point, but when the fire brigade turn up to a car fire they first thing they ask is about how much fuel is in the tank. The less there is the more worried they are. I've been in the situation twice. Presumably an explosion is more worrying than big flames.

<comment><USER21> Ehh, I mean, they already know there is a fire and that fire getting bigger is something they anticipate one way or the other, but an explosion could take them by surprise.

I _suspect_ that more people are killed by big flames than explosions, but more _fire fighers_ are killed by explosions than big flames.

</comment></comment></comment></comment></comment></comment><comment><USER23> Two things.

1\. I have had my gasoline car catch on fire in my lifetime. (That was the end of the car.) However, it was having a lot of trouble at the time and we had just taken it to the mechanic. (That's right, it caught on fire at the mechanic's shop. We were still waiting to talk to the mechanic before going back home when it caught on fire.) This was not the only on-fire incident among our friends. One had his minivan catch on fire in a gas station.

But both of them were old cars. What is to say that most of the cars that catch on fire aren't much older than the Tesla? What is to say that the Tesla won't have more trouble as it gets older?

Oh yeah. The batteries will have to be replaced before the car is run down as much as our old beaters were. And Tesla owners will have the money to maintain their cars better than we did as teenagers.

So, what I'm saying is that the real test will be in a decade. More fires will probably happen, just like regular cars do.

Either way, it's probably not dangerous enough to be worth avoiding buying a new one.

<comment><USER24> Curious as to your reasoning on saying that the batteries will have to be replaced before the car is as run down as your old cars. So far evidence is pointing towards batteries lasting much longer than originally thought. How old were your cars?

<comment><USER25> They still HAVE to be replace whereas a 30 year old car can continue to run a Teenagers budget

</comment></comment></comment><comment><USER26> I really don't care about "it would be worse if it were a gasoline powered vehicle". That statement is simply trying to redirect attention. Leave statements like that out of the problem diagnoses and simply concentrate on what went right.

Otherwise it looks like making excuses and that is bad.

<comment><USER27> To some extent the comparison needed to be made based on the media reports calling into question the overall safety of EVs based on this incident. The closest equivalent for conventional vehicles is a gas fire so pointing out the (apparent) greater danger makes sense here.

</comment></comment><comment><USER15> _Initial attempts to douse the fire were unsuccessful. "The fire appeared to be extinguished, then reignited underneath the vehicle," the report said. Firefighters had to use a jack to turn the Model S on its side, and then cut a hole in the car to apply water to the burning battery._

He seemed to skip that last bit. (?)

<comment><USER28> I have seen videos of normal gasoline car fires that behave the same way.

<comment><USER15> What did they use to cut the hole in the gas tank with? Just curious.

</comment></comment></comment><comment><USER15> A little closer reading of the report[1,2], shows that only 26,000 automobile fires occur on public highways. That makes Tesla's single datapoint worse than a conventional Auto.

All cars: 1 fire per 116 million vehicle miles/year

Tesla: 1 fire per 113 m vehicle miles/since inception

Obviously, the Model (s) being a newer Tesla model does not have the full historical amount of "Tesla" Miles as the denominator.

[1] [http://www.nfpa.org/~/media/files/research/nfpa%20reports/ve...](http://www.nfpa.org/~/media/files/research/nfpa%20reports/vehicles/osautomobilefires.pdf)

[2] Furthermore, only 2% of non-deliberate fires start in the fuel line or fuel tank of a normal vehicle

</comment><comment><USER29> Wow, first serious Tesla road accident and all they can say is how unlikely it was. It was impossible before, now it's only extremely unlikely. Until next time? There are probably many other ways to destroy the battery in a collision, how likely is it to ignite when damaged?

<comment><USER30> It was never "impossible before". Just two months ago when writing about Model S's safety rating, they stated that it was unlikely to remain the case forever that a Tesla car has never caught fire or caused an occupant fatality.

They've always published First Responder fact sheets for their cars which talk about how firefighters should handle a battery on fire.

[http://www.teslamotors.com/sites/default/files/downloads/201...](http://www.teslamotors.com/sites/default/files/downloads/20130214_ModelS_Emergency_Response_Guide.pdf)

</comment></comment><comment><USER31> As much as I admire the work Tesla and Elon Musk are doing, I can't help but feel that the press releases issued by the company are at times overly defensive.

We all know there is negative rhetoric bouncing around about this incident. It seems to me that, _precisely because of this_ , there really isn't a need to write in such a manner—trying to block all possible avenues of attack as if one is a afraid of what will be written in response.

The tone, to me, betrays insecurity, and this seems something at odds with the bullish, innovative nature of the non-PR aspects of the business.

</comment><comment><USER32> The following statement is wrong at many levels.

"That equates to 1 vehicle fire for every 20 million miles driven, compared to 1 fire in over 100 million miles for Tesla. This means you are 5 times more likely to experience a fire in a conventional gasoline car than a Tesla!"

\- All Tesla cars are new and almost all of them have superior drivers.

\- They drive their cars only on certain roads where as Gasoline cars are almost everywhere.

\- You can not compare 100m sample set with 2 trillion size sample set.

<comment><USER33> And he forgot to mention many gasoline car fires aren't due to gasoline ignition, but electrical failures or material melting (plastic/glue), etc. The only common case of gas ignition is static electricity while filling up, f.ex. re-entering the car while wearing a sweater (you can even smoke a cigarette while filling up, it's the spark that's dangerous). Closed gasoline tanks have been safe for decades and contrary to what we see in movies it's close to impossible to fire them up even in serious car crashes, especially when they're full. There is even a method for extreme freezes (-30-40'c) to light a small fire under the tank to help the fuel flow to start the engine (especially needed for diesels and low quality gasoline) and the only fires due to that are when the stupid owner didn't realize his tank or other parts around are plastic (which's quite a modern day problem).

</comment></comment><comment><USER34> Excellent post-mortem!

And who would have thought a side-effect of disrupting the automotive industry would be training fire-fighters on the correct techniques for battling a lithium fueled fire?

</comment><comment><USER35> I wonder what he means by 1/4" armor plate - AR500? Is it actually rated for armor plating, or just built with material from which you could also build rated plates?

</comment><comment><USER36> Why are people on HN so keen on defending Tesla at all cost?

</comment><comment><USER37> The title is missing word "incident". My first thought was that Tesla has a new model "S Fire".

<comment><USER38> A car called Model S Fire would be like a software package called Microsoft Crash.

</comment></comment><comment><USER39> So a truck driver who couldn't be bothered to secure his fucking load just cost Tesla shareholders $1b+?

<comment><USER40> I haven't seen the debris but it could have been part of the trailer itself. Not that it makes it any better. Things should _not_ be falling off of trucks. Just saying that it might have been a maintenance issue or some kind of freak accident.

That being said, If that part had punctured a gas tank of a petrol vehicle the damage could've been _explosive_ or caused a fire also.

I like how they have calculated how this happened because that most likely means in the next revision they may improve the skid plate or the battery wall to protect it from such things. Or recall them and retrofit, if needed. They aren't being mysterious like I've seen from other auto manufacturers. But then again, not every company dives in $1B in worth after a car has an accident.

<comment><USER41> In liquid form, gasoline isn't all that excited about exploding.

Mythbusters did it:

[http://dsc.discovery.com/tv-shows/mythbusters/mythbusters- da...](http://dsc.discovery.com/tv-shows/mythbusters/mythbusters- database/shooting-gas-tank.htm)

<comment><USER42> Yes, but a car/truck/van will turn into a ferocious little bonfire given the right kind of damage, an ignition source, and time.

<comment><USER15> IRL less than 2% of auto fires involve fuel lines/tanks etc. Your scenario tends to play out better for intentional fires, tho. So, yeah if you molotov cocktail a car it will ignite...but it does not do so under typical use hardly ever.

source: the same one Musk quoted.

</comment></comment></comment></comment></comment><comment><USER43> If Toyota owners got one of these emails every time one of them caught on fire it would be sort of a downer, so I guess you only have a few chances to make it a PR event.

</comment><comment><USER44> I've blogged a fun writeup of the math in the (unimportant and actually against Tesla) formal bias in evaluating a failure rate right after the first failure: [http://www.win-vector.com/blog/2013/10/estimating-rates- from...](http://www.win-vector.com/blog/2013/10/estimating-rates-from-a- single-occurrence-of-a-rare-event/)

</comment><comment><USER45> "Had a conventional gasoline car encountered the same object on the highway, the result could have been far worse."

Diesel-powered car would be much safer, since oil requires something like a wick in it to burn. It's hard to argue with Tesla's statement, since argument is true; but it doesn't include this issue in electric vs ICE vehicle competition.

</comment><comment><USER46> > This means you are 5 times more likely to experience a fire in a > conventional gasoline car than a Tesla!

I LOVE THE COMPANY. I DON'T ENJOY OR APPRECIATE THE LAME MARKETING ATTEMPTS THEY SOMETIMES MAKE. Just like that whole business of jumping through hoops to make it seem like there was some new magical way to finance a Tesla, this is wrong.

Trying to create a safety metric by comparing the number of fires to the number of miles driven per vehicle type is pure nonsense. You have to look at the causes and mechanisms of the fires and dig a lot deeper than that in order to even hope to generate a meaningful metric.

Here's an imperfect analogy (numbers made-up): One million people run marathons every year world wide. 1000 have heart attacks and die. Ten thousand people have run marathons with our shoes and only one had a heart attack and didn't die. You are far less likely to have a heart attack and die if you run marathons with our shoes.

Nonsense. Right?

RIGHT.

Almost anyone would look at that and recognize it as a poor attempt to create a nexus where one does not exist. I think it's bad marketing.

Now, if we started to dive into the statistics and identified location, weather conditions, age, physical conditioning, pre-existing conditions (heart problem they did not know about), etc. we might actually be able to attempt a comparison between people wearing the new shoes vs. the other brands. Even then, the nexus would be tenuous at best.

A similar exercise would be needed to compare car fires between brands and types with any degree of validity. I don't have the time to dive into the stats. It was easy enough to Google [0][1][2][3] and do a quick scan:

It is easy to see that young males are more likely to be involved in a car fire.

There are statistics about different brands having different fatality rates (not necessarily related).

Lots of fires are caused by running equipment. Lots of fires originate in the engine compartment. Mechanical and electrical failures seem to account for over 60% of fires.

The point is simple: Far more extensive and detailed statistical work needs to be undertaken before anyone can conclude absolutely anything on the merits of any particular car or design as it pertains to potential to cause fires.

Elon and his team are very smart. They know this. And this is why some of their marketing of late feels really dirty and beneath them. This is Tesla reacting to news that affected their stock price and, potentially, buyer sentiment, with marketing rather than the truth.

Are Tesla's safer than all gasoline cars? That question is probably not an easy one to answer at all.

There's the potential for a theoretical sort of an answer based on design. For example, there are no fuel lines to rupture. Does that mean it is safer? Hard to say. What do you compare that to? Perhaps you can list all the potential sources of ignition and sort them by probability and MTBF? Not sure.

Of course, then you have the real-life probability. Once you get a million cars on the road with all kinds of people, driving in all conditions, roads and levels of maintenance and neglect things can change dramatically. If I remember correctly Tesla has somewhere in the order of twenty thousand. There's a reason we see major car companies recall hundreds of thousands of cars every so often. Shit happens. Design error are made. And it can take time and a massive installed base to discover them.

THE TRUTH OF THE MATTER is these are the kinds of tests electric cars will have to endure over a period of time in order to reach wide adoption. Despite what's been said here a full tank of gasoline is far safer than a fully charged battery pack with enough energy to go 300 miles.

Before anyone mauls me, consider how many gasoline cars have been driven and, yes, crashed, world-wide since gasoline cars came into mass production. Not last year. Since forever.

There have probably been millions of accidents without fires, even with fuel leaks. There's probably no imaginable way to compare the two at this time. We simply don't have enough data. And, no, linking to a horrible crash video on youtube involving gasoline igniting does absolutley nothing to support arguments on either side.

The one issue with electrics that is not spoken of is the fact that you have a several hundred volt high energy system that could very well electrocute passengers. I fully expect that to happen one day (in general, not necessarily Tesla). If and when that happens you can bet it will set the breaks on electrics for a while and relevant stocks will plummet.

I still believe electric cars are the future. We simply need to go though the evolutionary process that will make them really safe for hundreds of millions of electrics to share the road. What happens when you have a pile-up of ten or twenty electric cars on a fogg-covered highway? A pile of mangled wrecks with 400 Volt high energy systems is unimaginably dangerous. I can think of a few horrific scenarios under those conditions.

At some level part of me thinks that fuel cells are the future, not batteries. Having something relatively benign that can leak out would be a good thing.

A few months ago there was a horrific crash in my neighborhood. This 18 year old kid decided it was OK to go 100 miles per hour on this avenue. He lost control and plowed into a bunch of cars parked by the side of the road. He absolutely destroyed seven of them before coming to a stop. Most of the cars were mangled beyond recognition. He was driving an SUV with a lot of mass. His SUV was nearly cut in half and impaled into one of the cars to a degree that made it difficult to see where one car started and the other ended. Almost like taking two lumps of play-doh and mixing them together.

No fire. Gasoline all over the place but no ignition at all. He hit the first car, fused into it and the "ball" formed by the two cars proceeded to destroy the other six. Absolutely amazing display of how much kinetic energy was dissipated.

Had this been eight fully-charged electric cars I am almost certain there would have been a horrific fire as well as the potential for absolutely impossible to describe electrocution of some of the passengers. And, to make matters worst, it would have taken the rescue crew far longer to remove the victims as they would have to be worries about electrocuting themselves and the victims (at the very least).

Until there are enough electric cars on the road to have a massive pile-up accident [4] where most cars are electric we will not really understand the practical reality of a world where every car on the road is electric. Imagine having to walk out of a one hundred mangled car pile-up where every car has a battery pack storing enough energy to drive 300 to 400 miles and they are wired to produce hundreds of volts. I can't imagine anyone who understands electronics and electricity that would tell me all would be well after looking at the pictures from this accident [4] if all cars were electric. Look at pictures 1, 8 and 11. No fires. Gasoline isn't all that bad in this regard.

[0] [http://www.usfa.fema.gov/downloads/pdf/statistics/v13i11.pdf](http://www.usfa.fema.gov/downloads/pdf/statistics/v13i11.pdf)

[1] [http://www.usfa.fema.gov/statistics/reports/vehicles.shtm](http://www.usfa.fema.gov/statistics/reports/vehicles.shtm)

[2] [http://www.chandlerlawgroup.com/library/national-vehicle- fir...](http://www.chandlerlawgroup.com/library/national-vehicle-fire- statistics.cfm)

[3] [http://www.statisticbrain.com/driver-fatality-stats-by- auto-...](http://www.statisticbrain.com/driver-fatality-stats-by-auto-make/)

[4] [http://www.cnn.com/2013/09/05/world/europe/uk-huge-chain- rea...](http://www.cnn.com/2013/09/05/world/europe/uk-huge-chain-reaction- crash/index.html)

<comment><USER15> _No fire. Gasoline all over the place but no ignition at all. He hit the first car, fused into it and the "ball" formed by the two cars proceeded to destroy the other six. Absolutely amazing display of how much kinetic energy was dissipated._

Fuel tanks/lines and related systems cause only ~2% of Automotive fires in the US (excluding intentional ones).

</comment></comment><comment><USER47> I wrote a blog post on this last night (Tesla model S and the three laws of robotics).

[http://justink.svbtle.com/tesla-model-s-and-the-three- laws-o...](http://justink.svbtle.com/tesla-model-s-and-the-three-laws-of- robotics)

</comment><comment><USER48> Stakes are high, for sure

Elon Musk & Tesla would review its design, would possibly add protection for these type of accidents.

Will any other gasoline car manufacturer be willing to participate in such crash test what model S encountered, I doubt anyone will.

</comment><comment><USER49> wow. reading their report always inspires me to be a better engineer

</comment><comment><USER50> Totally thought this was a name for a new model S model, a la kindle fire.

</comment><comment><USER51> Tesla, recall is coming, that is obvious. You will be forced to put in stronger armor underneath. So drop the price by $10K, or do the recall sooner. Either way that is the reason for the stock hit, people know one or the other or both are coming.

</comment><comment><USER52> > "highway speed"

crafty writing. read it as "high speed"

<comment><USER21> "highway speed" is a fairly common term for the general 55-70mph range. For example, apparently the instructions to have the emissions testing system on my car become "ready" after a battery disconnect involve "at highway speed" for a half an hour or so _(I learned that one last week. Fun times.)_

</comment></comment><comment><USER53> He is just great

<comment><USER53> Downvote me for my opinion you HN haters bring it on

</comment></comment><comment><USER54> Fire happens. Maybe Tesla performs better, maybe not but cars do catch fire. I, however, will not be buying Elon's explanations simply because he seems like a cheesy salesman and a media whore. [http://www.bloomberg.com/news/2013-04-02/tesla-to-begin- mode...](http://www.bloomberg.com/news/2013-04-02/tesla-to-begin-model-s- financing-with-u-s-bancorp-wells-fargo.html)

(Knowing the Elon is the Sun God among many here, I want to say this: I do not particularly care about karma, I'm saying 100% of what I am thinking.)</comment>


Show HN: `loop`, Unix's missing loop commmand - <AUTHOR> https://github.com/Miserlou/Loop <comment><AUTHOR> I have always found writing loops in Bash to be fickle, tedious, and needlessly complicated.

`loop` allows you to write intuitive, powerful looping one liners, with many useful features like breaking on pattern matching, timed loops, and loops for a specific duration.

For instance, to try a thing until it succeeds, every 15 seconds, for a maximum of five times in Bash:

        n=0
        until [ $n -ge 5 ]
        do
           do_thing.sh && break
           n=$[$n+1]
           sleep 15
        done

becomes:

        loop './do_thing.sh' --every 15s --until-success --num 5

This was also my first Rust project, so feedback is welcome!

</comment><comment><USER2> Very useful but nothing UNIX about it</comment>


Ask HN: 5th year masters vs. masters at another school? - <AUTHOR> What do you think about getting a combined 5 year BS/MS in computer science (for example, at UW in Seattle), as opposed to doing an undergrad in CS and then doing a masters in CS elsewhere?<p>This is for someone who isn't very interested in academia research/getting a PhD, but is interested in industry/industry research. <comment><USER2> I think if you are interested in research what matters at the end of the day is that you do something that interests you (with a professor that shares your interest and is willing to take you on).

If your school has a research group where you could potentially envision yourself, then why not? You could even join as a BS student and by the time your program ends, you'll have a bunch of research experience.

Alternatively, changing schools for MS in general I think is a decent idea for some, as the change of environment can be beneficial for productivity.

Good luck!

</comment><comment><USER3> To me, it mostly comes down to whether you want to keep living where you are living or live someplace else and (be forced to)/(have the opportunity to) meet new people. Independent of that, more school in something that is/isn't personally interesting factors out as a common denominator. Keep in mind that the choice isn't binary. Moving is orthogonal to whether or not you even choose to pursue an masters. Good luck.</comment>


Show HN: Better Postgres job scheduling - <AUTHOR> https://github.com/GoSimpleLLC/jpgAgent <comment><USER2> Wow, great project. I worked in a place that uses pgAgent heavily, and this address all major pain point with it, aka, parallel steps and max parallel job.

<comment><AUTHOR> Really appreciate the feedback. Yeah, those were big pain points for me too... I originally wrote v1 over a weekend because I was getting really frustrated with pgAgent crashing on me at random, and jobs would just stop working with no notification or anything. After that I decided to add some of the features I missed from Sql Server Agent, and it kinda evolved from there.

At this point i've got a server that's been running the agent for 6 months with 0 down time, so i'd consider that a success compared to the weekly downtime i'd have at random with pgAgent. Plus the job failure notifications are a life saver for me.

</comment></comment><comment><USER3> It's unclear - What is this supposed to be better than, and what about it is supposed to better?

<comment><USER4> It seems to me it's extremely clear from the first paragraph - it's supposed to be better the pgagent, and the second paragraph lists all the new features that make it better then pgagent.

<comment><USER3> It's unclear because the second paragraph is about why the replacement is compatible with pgAgent, literally, "The reason for..." \- not that it _is_ a replacement.

It could also be a replacement for something else that runs on top of pgAgent, or something else that doesn't, and one of the features is that this _is_ compatible.

Does that make sense?</comment></comment></comment>


Power naps, power snack, power training: power everything - <AUTHOR> http://blog.cozycloud.cc/productivity/2013/09/18/power-naps-power-snack-power-training/ <comment><USER2> I see there is a market for a power bulshitting app which for every time you spew some, I get a dime so you can keep an eye on yourself.

Cramming your life between fleeting moments during work is not healthy however you quantify it. 7/24 working mentality is not a virtue. Only reason I see for advocating such bullshit is if you have a vested interest for hiring lifeless worker drones or in business of giving unwarranted life advice, incidentially which I excel at too.

Please, please, please, don't kill yourself before you had a chance to live. The junk in your pocket neither should decide how you will live your life nor could reward you. What can it give you? XP points so you level up?

</comment><comment><USER3> The few times I had to wear smart trousers in the office I used to refer to them as my Executive Power Slacks.

I wonder if he will write a blog on them.

</comment><comment><USER4> I'm not sure I'd look to the Japanese workforce for balance.

</comment><comment><USER5> Power sleeping, power eating, power lifting... [https://www.youtube.com/watch?v=qRuNxHqwazs](https://www.youtube.com/watch?v=qRuNxHqwazs)

<comment><USER6> This may not be reddit. But you got a point: It is really irritating that this post with this title is seemingly written with a straight face.

On the one hand, there is the burnout discussion regarding managers, and on here of course especially also regarding IT-people and founders. On the other hand, there is a semi-corporate culture treating things like tiredness, exercise and food as something one has to conquer with willpower and buzzwords from quantified self and power everything. Something one has to put a lot of energy into to do properly, all with the aim to be even more productive.

As if it was impossible to simply take the time to eat properly, at least once a day, with your colleagues. Or get home early enough to be able to exercise twice a week. Or don't work night and day so one gets enough sleep.

</comment></comment><comment><USER7> Bro, do you even nap?</comment>


Ask HN: Which JavaScript framework changes the least? - <AUTHOR> Been following NetNinja's Firebase/React/Redux tutorial. Was doing well until I ran into an incompatibility with the current version of react-redux-firestore package and the newest version of react. Not exactly sure what the issue is aside from React moving away from const JSX and react-redux-firestore package recommending I use the v3-alpha in it's place.
I am still new to mastering JS programming so using an alpha doesn't appeal to me. Plus, I have had similar issues with JQuery and Angular in the past-where they just break things.
What is a good JS framework for single page apps that tries not to break things?
It would be nice to watch a tutorial and not fret that because it's 6 months old it is out of date and things may break. <comment><USER2> Hi, I'm a Redux maintainer.

We recently released React-Redux v6 [0]. The major change for this release was how React-Redux internally makes the Redux store state accessible to nested components, by switching from React's old (and broken) context API to using the new context API. I wrote a blog post about the technical details of the change and why we did it [1].

A number of libraries in the ecosystem were accessing the Redux store directly out of legacy context, which was not part of the React-Redux public API. Because of this, those libraries broke when used with v6 (as described in our release notes).

Note that this was not an issue with React or Redux themselves. This was caused by other libraries in the ecosystem relying on non-public implementation details, which are always at risk of breaking no matter what the library or language is.

As you noted, react-redux-firebase is working on updating itself to work correctly with the latest version of React-Redux. (We've also added some docs to React-Redux that describe how libraries can safely access the store directly [2], albeit with the caveat that this is still not directly part of the public API.) You can also stay on React-Redux v5 and the existing version of react-redux-firebase if you'd like. There's nothing specifically wrong with those versions, and they still work together.

Let me know if you've got any questions on this.

[0] [https://github.com/reduxjs/react- redux/releases/tag/v6.0.0](https://github.com/reduxjs/react- redux/releases/tag/v6.0.0)

[1] [https://blog.isquaredsoftware.com/2018/11/react-redux- histor...](https://blog.isquaredsoftware.com/2018/11/react-redux-history- implementation/)

[2] [https://react-redux.js.org/using-react-redux/accessing- store](https://react-redux.js.org/using-react-redux/accessing-store)

<comment><USER3> Disclaimer, I don't use React-Redux. However, I can't help but be puzzled, if the core of this issue is people using private APIs why did you create a new release with another, simply different private API? Why not either keep the private API the same or make a public interface, since it seems a popular necessity?

<comment><USER2> Link [1] in my comment describes why and how we changed from using the legacy context API to the new `createContext` API.

</comment></comment></comment><comment><USER3> I would suggest using Vue.js[1]. It's the most popular library following React[2] and one of the strong original pioneers in the field.

One of the strongest sides of Vue is that it's opinionated and very easy to get started with; if you've used React before you'll feel right at home. While the library obviously keeps evolving over time, most of the knowledge applicable from version 1 from years ago is still relevant today — the core API is very stable.

Most of all, however, I would like to highlight that keeping up to the bleeding edge of any ecosystem in the modern frontend world will be a pain. You don't have to use the latest release of everything, use a good stable build and you'll run into a lot less headaches.

[1] [https://vuejs.org/](https://vuejs.org/)

[2] [https://2018.stateofjs.com/front-end- frameworks/overview/](https://2018.stateofjs.com/front-end- frameworks/overview/)

<comment><AUTHOR> I like your post. Been considering Vue for a while.

> You don't have to use the latest release of everything, use a good stable > build and you'll run into a lot less headaches.

In the above case, there was a security vulnerability with React with the older version that still worked with v2 of the firebase library.

I asked this question because I wasn't happy seeing React just make breaking changes and cut support off like that.

<comment><USER2> What "security vulnerability" are you talking about?

None of React's recent releases have had anything to do with security vulnerabilities. And, as I described in my other comment, the changes were in _React-Redux_ , not React, and the changes that broke other libraries were not considered part of our public API.</comment></comment></comment>


Does CSS performance is a thing? - <AUTHOR> How do we calculate it? Using a framework like twitter-bootstrap is too slow or starting from zero worth the hustle. <comment><USER2> CSS performance is a thing, both the transfer of the CSS and the actual performance of it.

Transferring unused CSS is a common problem, and adds weight to the page or more resources to download before rendering (rendering is blocked until all CSS has been retrieved and parsed).

CSS selectors have different performance, though it's negligible on most users devices today. One common misunderstanding is the way CSS selector are processed. They are processed from right to left, so a "#mystuff div" will actually lookup all div's in the page and check if it's a child of #mystuff.

I never use any frameworks, they are not worth the hassle. Just start from zero (expecting you actually know enough CSS). Typically, when I write CSS from the ground up, it's just a few kilobytes without any unnecessary code. Using more targeted CSS (I try and keep everything referring to ID's or specific classes) you will also end up with less HTML (no "button button-big button-blue button-shadow" classes all over the place).</comment>


Switching Jobs - <AUTHOR> https://flowingdata.com/2017/11/16/switching-jobs/ <comment><USER2> The top jobs that computer programmers switched to are all other computer related jobs, some nearly identical depending on how you treat the term programmer, vs developer.

Kind of depressing that once you become a computer programmer, you can't really escape computer work. Id like to hear more about people that go on to do something totally different successfully, like baking. Maybe its too uncommon. Also interesting, the top non computer jobs are lawyers and judges, and then accountants.

<comment><USER3> > Kind of depressing that once you become a computer programmer, you can't > really escape computer work

Can't, or not rational to?

The monetary returns to being a dev vs. other lines of work are high and have been growing for the last 2 decades.

One can do much worse than golden handcuffs.

<comment><USER4> > I see young men, my townsmen, whose misfortune it is to have inherited > farms, houses, barns, cattle, and farming tools; for these are more easily > acquired than got rid of. Better if they had been born in the open pasture > and suckled by a wolf, that they might have seen with clearer eyes what > field they were called to labor in. Who made them serfs of the soil? Why > should they eat their sixty acres, when man is condemned to eat only his > peck of dirt? Why should they begin digging their graves as soon as they are > born?

</comment></comment></comment><comment><USER5> Is there any way to view the inverse, "Which professions were most likely to switch to X?" I'd be interested to see where most developers are coming _from_ , instead of where they're switching _to_. I couldn't figure out how to see that information from the page.

<comment><USER6> As one data point, I was a furniture upholsterer before I switched to development.

<comment><USER7> How did you make the switch? Did you have practical experience beforehand? Or did you take courses?

<comment><USER6> I spent some time messing around with QBasic and Microsoft FrontPage when I was a kid, but that was about the extent of it. I was able to get a grant from the government (thanks Obama!) for college and got a CS degree at the local state university.

Overall, I'd say it was an excellent investment on the government's part. They spent a few thousand on grant money and will be getting hundreds of thousands of dollars in tax revenue over my lifetime from increased earnings.

</comment></comment></comment></comment><comment><USER8> There are some interesting quirks in the data if you click through the 'see a random occupation' button enough times. I wonder if they're artifacts of the sample size, or of the way certain professions are classified. Of people in the following professions who left their jobs -

Power plant operators, distributors, and dispatchers:

* 33% became Food batchmakers

* 11% became Bakers

Veterinarians:

* 46% became Actuaries

* 36% became Software developers, applications and systems software

Fish and game wardens:

* 87% became Detectives and criminal investigators

Psychologists:

* 25% became Urban and regional planners

<comment><USER9> With the game wardens, I wonder if it's common to transition into the state or county police

<comment><USER10> Not sure about game wardens, but all state and county park rangers in California where I am at are also law enforcement officers so I assume that makes it a relatively easy transition.

</comment></comment></comment><comment><USER11> It seems ... unlikely that physicians switch to become pharmacists, optometrists, or physicians assistants.

[https://imgur.com/a/AKEus](https://imgur.com/a/AKEus)

<comment><USER12> Interesting. I wonder if that's a data cleanliness issue?

eg; one year a Dentist says they're a Physician (maybe they didn't see the "Dentist" category) and the next year they say they're a Dentist.

</comment></comment><comment><USER13> I don't have a ton to say about the content of the article other than a super boring, "that was interesting." One thing that was cool is the chart labeled "Switching Rate for Different Jobs." I've never seen that style of chart before and found it really effective for sharing the data. Does anyone know what that is called?

<comment><USER14> It's a clustered bubble chart that's been ordered. Clever.

<comment><USER15> It also doesn't render in desktop Safari.

</comment></comment></comment><comment><USER16> There was nothing truly surprising about the findings themselves but I will say that they were presented very well and intuitively. That was the real value in this article and something other similar articles can learn from.

</comment><comment><USER17> This is such a rich dataset and I'm sure there are some very interesting insights. But I was very disappointed with most of the data visualization; the primary question of the article is addressed in a set of bar charts for a single occupation. There's no way at all to gain any complex understanding of the systems at play here with such a keyhole view of the world.

I'd like to see the career switching dataset in different forms to see what insights we could derive: network diagrams, heatmaps, and so forth -- visualizations that show the complex interconnectedness of this rich data.

</comment><comment><USER18> Masterful data visualization. Simple and informative. Thank you!</comment>


M0n0wall 1.8.1 released - <AUTHOR> http://m0n0.ch/wall/downloads.php

<comment><USER2> Minimum hardware requirements: "This version (any platform) requires at least 128 MB RAM and a disk/CF size of 32 MB or more."

It's a shame this isn't portable to ARM systems, where $50-100 buys you much more than that. Buying a small, low power x86 system in quantity 1 raises the overall price significantly.

<comment><USER3> Damn.. this is one of the best firewalls available that I haven't used because it won't work on the embedded hardware I have. I'd (figuratively) kill for this on a Pi.

<comment><USER4> It's primarily a GUI on existing OS tools - you could create a version that uses Linux commands instead of FreeBSD.

</comment></comment></comment><comment><USER5> Every once and a while I get lost in the vortex that is the gallery of user submitted M0n0 devices:

[http://m0n0.ch/wall/gallery.php](http://m0n0.ch/wall/gallery.php)

</comment><comment><USER6> I remember the first time I installed m0n0wall on a p3 500Mhz in high school and being stunned how beautiful everything worked. Nowadays I mostly use PFSense or Vyatta.

</comment><comment><USER7> Went to PFSense and never looked back.

</comment><comment><USER8> I was a long-time m0n0wall user on the Soekris platform but switched to pfSense running in a VM under ESXi last year because the little Soekris just couldn't keep up with modern home internet speeds. In the end, it was a very positive change and I wrote a blog entry on the somewhat peculiar hardware setup that I chose to replace the little Soekris:

[http://output.chrissnell.com/post/39550480075/the-jack-of- al...](http://output.chrissnell.com/post/39550480075/the-jack-of-all-trades- home-server)

</comment><comment><USER9> Is there an API for making changes? That's the single biggest annoyance with my current solution in that space, pfSense. Automating changes is _terrible_.

I didn't see it in the feature list, but that doesn't mean it doesn't exist.

</comment><comment><USER10> Interesting fact:

m0n0wall is made by the same guys that make Threema: [https://threema.ch/de/](https://threema.ch/de/)</comment>


Unix Toolbox - <AUTHOR> http://cb.vu/unixtoolbox.xhtml <comment><AUTHOR> > This document is a collection of Unix/Linux/BSD commands and tasks which are > useful for IT work or for advanced users. This is a practical guide with > concise explanations, however the reader is supposed to know what s/he is > doing.

Something I bookmarked back in June 2010 :-)

</comment><comment><USER2> Most recent previous submit, 490+ points:

[https://news.ycombinator.com/item?id=10022729](https://news.ycombinator.com/item?id=10022729)</comment>


Android Growing Faster Than All Other Mobile Platforms (In the US) - <AUTHOR> http://phandroid.com/2010/03/10/android-growing-ridiculously-faster-than-all-other-mobile-platforms-in-the-us/

<comment><USER2> Obviously Android is growing, but this rhetorical trick to make the growth look RIDICULOUS is... ridiculous.

I'm not sure why this analysis stopped in October 2009. Why not go back to October 2008? Then the stats would look something like this:

      all other phones:
        sales in October 2008: finite
        sales in Jan 2010: larger
        percentage increase: big

      Android phones:
        sales in October 2008: zero
        sales in Jan 2010: large
        percentage increase: INFINITY!!!

In other words, I assert that one big reason why Android has grown so fast since "the three month period ending in October 2009" is that before then there was only one or two Android phones, they were all from HTC, as I remember they were rather poorly marketed, and as a result they sold modestly but not spectacularly. When you're down that far, there's a lot of upside potential.

Take a look at this chart:

<http://en.wikipedia.org/wiki/List_of_Android_devices>

What you will see is that the bulk of Android-powered devices, including the ones with the big popularity and big press from Motorola and (of course) Google itself, all came out after October 2009.

Cherry-picking certain parts of the sales growth curve and then extrapolating them to infinity does not add additional information. Take the data for what it is: The newest Android-powered devices are selling much, much better than the old; Apple's three-year-old iPhone platform has reached a marketshare plateau (not astonishing: three years is a long time in the phone market; unlike Android the iPhone OS is only available on a few types of device from one vendor; and in many markets the iPhone is chained firmly to specific telecom vendors, as Bay Area AT&T customers know all too well). Meanwhile, it sure is nice to be RIM, Microsoft's marketshare is doing about what everyone expected, and, well, it's really too bad about Palm.

EDIT: Oh, wait, these are _smartphone subscriber_ stats. As such they probably don't include Apple's iPod Touch or other non-phone devices. (e.g. Does the Nook count?) When judging the installed base of the _software platforms_ , rather than the size of various markets for cellphone minutes, this is a big omission, since Apple is known to do a huge iPod Touch business.

<comment><USER3> To be fair, Android also had the largest total increase in market share by increasing 4.3%, whereas the next highest total increase was 1.7%. That is pretty significant.

</comment></comment><comment><USER4> As the newest mobile OS on the market, I would be very surprised if Android's growth stats weren't large compared with the mature platforms.

<comment><USER5> Except Android is older than WebOS.

</comment></comment><comment><USER6> As Timthorn mentioned, a high growth rate from a small base isn't really impressive. Last year, it was on one U.S. carrier, and T-Mobile at that. Now, everyone but AT&T has it.

Aside from that, however, Android's tackling a range of devices from the high end tier to what the industry terms "feature phones," devices that hope to tackle one area and tackle it really well (i.e., photos, texting, social media). These are lower margin but higher gross, and for now, completely uninteresting to Apple but Android provides a perfect platform for crafty manufacturers to quickly churn them out.

<comment><USER7> The Nexus One is a better phone than the iPhone for the technologically adept. Apple is not uninterested; its recent lawsuit against HTC is testament to its fear.

<comment><USER8> Maybe it is, but it does give a very unfinished feeling when just about everything scrolls at like 10-15Hz instead of silky smooth as iPhone does.

<comment><USER7> For sure, and e.g. the media player is quite clunky, and the SD card has no standard layout. But the ability to have e.g. my todo list, or my calendar items, or a twitter feed etc. as widgets on my home screen is more tangible. And application association mechanism is useful too - I can replace the various media players, browser etc. and actions from different applications respect my wishes, rather than following some one true way. And I can get notifications and alerts from background apps - works really well for me monitoring various remote services.

</comment></comment></comment></comment><comment><USER9> The growth is quite good, i am happy for that. But it is not RIDICULOUSLY faster. This interpretation of statistics is just too much.

It's probably why i stopped reading phandroid. My suggestion for android news: <http://www.planetandroid.com/>

</comment><comment><USER10> I don't really understand all the comments saying "of course it's growing extremely fast, it's a new platform". The point is that a year ago it wasn't at all obvious whether Android will become one of the major mobile platforms - now it's practically certain.

Yes, there's hyperbole in the article (what do you expect from a site called "Android Phone Fans"), but I really don't understand the attitude that, since it's a new platform, its growth is somehow self-evident. Many (most?) new platforms never take off - how's Palm doing, for example?

See:

<http://metrics.admob.com/2010/01/metrics-update-android/>

and tell me that's not a curve most platforms can only dream of.

</comment><comment><USER11> It is growing fast. It has more than doubled its market share. I don't care how small the actual starting number was, it is still good progress. If you don't think so, go ask Palm!

On a similar note, the rapid Android evolution, I think, might actually be harmful. I have been without a contract for over a year now. I have been wanting an Android phone. However, each time I settle for one, a new and better one rises over the horizon. So I wait. By the time that one comes to market, the pattern is repeated.

Another real interesting story, from this data, is that the iPhone growth has become stagnate. Looks like Apple hit the ceiling! Unless of course they add in iPad sales numbers next year.

<comment><USER12> _I have been without a contract for over a year now. I have been wanting an Android phone. I have been wanting an Android phone. However, each time I settle for one, a new and better one rises over the horizon. So I wait._

Contract-free Nexus One plus month-by-month with T-Mobile. There's nothing significantly better due out for several months, and if you want to upgrade in a year or so you won't have a problem selling it.

</comment></comment><comment><USER13> I know I should not expect too much from "Phandroid.com", but the only thing ridiculous here is the way this guy cooks the numbers. If RIM saw twice the growth as Android they would score 20.8% on his chart. The percent change in percents is not a meaningful number.

</comment><comment><USER14> RIM grew three times faster than Apple during this period.

</comment><comment><USER15> I mean realistically, a huge number of people already have an iphone/blackberry, and the android phones are just starting to be good enough to buy.

</comment><comment><USER16> It will be interesting to see what happens in the US now that all 4 major carriers have TV ads featuring Android phones.

</comment><comment><USER17> Fast growth is pretty easy when it's growth from zero.</comment>


Lisp Flavored Erlang (LFE) Quick Start guide - <AUTHOR> http://lfe.github.com/quick-start/1.html <comment><USER2> This is a great awesomeness.

It provides all access to rock solid erlang vm/otp/library with lisp nice syntax. If you look at the source code, you will see that it is quite small, meaning you can expect reliability. All this implemented by one of the Erlang creators with 30 years experience in designing and implementing great platforms.

I am just amazed by the potential.

</comment><comment><USER3> The main "docs" page [1] and the previous HN discussion [2] are a bit more useful than the install instructions linked to this submission. Also on the "docs" page is a video from 2011, but I haven't watched it yet (still downloading).

[1] <http://lfe.github.com/docs.html>

[2] <http://news.ycombinator.com/item?id=286288>

<comment><USER4> Yeah, the quick start is just intended to get folks going. The "Docs" page definitely has a lot more useful stuff there!</comment></comment>


Show HN: A coding style proposal for JavaScript ES6 - <AUTHOR> http://lucidogen.github.io/jessy/ <comment><USER2> I think the "Single line commit changes" is a worthy goal. But I don't think these changes make this more possible.

<comment><AUTHOR> It is true. It only improves this aspect when adding elements to the end of objects.

But the real advantage I felt was punctuation confusion reduction when having mixed object definitions and callbacks.

</comment></comment><comment><USER3> The proposed format kills the readability of nested objects IMO.

<comment><AUTHOR> I have been using this format with deeply nested objects and found readability to be improved. How does it kill readability ? Could you provide an example ?</comment></comment>


Apple: Can it stop the Android menace? - <AUTHOR> http://www.nakedcapitalism.com/2009/11/apple-can-it-stop-the-android-menace.html

<comment><USER2> I don't think that Android is actually a menace. Just a competitor. And really different (yeah, maybe Apple will lose a % of market share, but they still have a very well-profiled group of potential users)

</comment><comment><AUTHOR> I don't mean to brag about it, but I wrote a strikingly similar analysis _on the day that Android was announced._ It's in portuguese and the piece even got published by a larger portal in Brazil. I feel like I should translate that.</comment>


Making Text Mining Accessible to Any Developer & Non-Expert - <AUTHOR> http://blog.recursivity.com/post/13108173847/making-text-mining-accessible-to-any-developer

<comment><USER2> I have a good amount of experience in natural language processing and machine learning, and I don't think offering an API that provides easy access to the algorithms is the right solution. The major algorithms in text classification aren't that complex to implement, and can be done in a few hundred lines. Moreover, all of the most widely used, widely tested, and reliable algorithms have public implementations that are readily adaptable to your needs. And that's the problem: _understanding your needs_.

Understanding your needs (or your company's needs) is where people with PhDs make their money. Machine learning isn't a panacea, and we won't be seeing a one-size-fits-all approach for awhile. Even though data has become more accessible, it might be noisy, incomplete, streaming, partially labeled, etc. This is why understanding exactly what you're trying to model with these algorithms is crucial and why "just applying" them is impractical at best and misleading at worst.

<comment><USER3> Well. Here's my take.

There are a number of text analysis SaaS offerings such as OpenCalais, AlchemyAPI, Zemanta, and OpenAmplify. They've all got impressive science under the hood, but none of them are accurate enough to be useful.

I spend most of my time these days thinking about why that is and what to do about it.

For systems to do better, they'll need to incorporate world knowledge; they'll need to test different interpretations of a text and select the ones that "make sense". This is likely to be a form of statistical inference rather than Cyc style logic.

Based on some systems I've worked with, I'd estimate that a space optimized "background" knowledge base that can estimate satisfiability in the common sense domain is on the order of 10-100 GB. It will puff out to at least an order of magnitude beyond that in the process of creating it.

Few users will have the ability to create a KB of that type, and it would be a serious thing to download and install.

Hosting the services of that kind of system in a SaaS manner makes a lot of sense.

<comment><USER4> Without looking under the hood I'd say there could be at least four reasons why they fail (based on what most of the NLP literature is lacking):

\- did not remove contradicting information from the training sets (two very similar vectors having contradicting labels)

\- did not try enough feature selection algorithms

\- did not estimate ALL learner parameters using the training sets with internal CV

\- did not include domain knowledge

The last one refers to Paul Houle comment. Just, beside using tools like OpenCyc, WordNet, UMLS, there many other ways to embed domain expertise in an automated classification process. Injecting semantically related features into a vector representation of a document is extremely difficult. Forward feature selection doesn't work well for sparse and noisy data.

<comment><USER3> the curse of dimensionality is the worst problem that affects machine learning

customers don't want to create training sets large enough to train text classifiers; often the number of documents they need to sort into a category is too small to fit in a category.

As for semantic indexing, it was hard to do in 2005. In 2011 it's easy. DBpedia and Freebase are a chromosome map for the human memome. With large amounts of instance information, it's possible to do things that a big rulebox can't.

These tools are aiming for the market segment that Cyc aimed for, but will use very different methodologies.

</comment></comment></comment></comment><comment><USER5> Text mining is one of my specialties and I have had similar ideas for a business. One thing that has stopped me is the awesome (and free for about 50K API calls a day) Open Calais service that does entity extraction and identifies some relationships between entities in input text.

For document clustering there are many good open source tools that people and companies can use. The commercial Ling Pipe product does a good job at sentiment analysis.

Obtaining, scrubbing, and generally curating the data is a pain point that users of this system may still need to worry about.

I wish this new business good luck, but there are definitely some real problems to work around. Perhaps we should go into business together :-)

<comment><AUTHOR> True, but problems are there to be solved. :) We've done a lot of work around data normalization/scrubbing from a multitude of sources as part of a sister project, so I'm fairly confident about this aspect. Curation and classification is another issue, but we have a few ideas.

As for business, you never know, just let me try to get off this Ramen based diet first. ;)

</comment></comment><comment><USER4> Text mining: most of the time is spent on gathering the data, curating the data, and working with your annotators (domain experts). After that, you try _a dozen or more_ ways to covert documents into a matrix format. Then, you try _a dozen or more_ feature selection algorithms. Finally, the icing on the cake: you get to try _a dozen or more_ machine learning algorithms, each having _a dozen or more parameters_ to be estimated.

Yep, it would be very nice to have an API that would do all that for you. But that would require a group of at least 10 ML experts + 10 NLP experts + 20 domain experts. Still, I think it's doable and one should make small efforts to make it happen.

Marginal thoughts: _decision trees_ are very bad for large p >> n problems - random forest might work, though. If TextMinr doesn't have radial SVM with auto-tuning then it will not cope with more difficult problems.

<comment><AUTHOR> Appreciate your comment. And you're right about decision trees, though they can be useful for simpler problems, such as classifying documents into categories, whereby you have "sub categories" and the parent categories are mutually exclusive.

Decision trees are really only useful for problems where there is mutual exclusion between the different options, so they are definitely no silver bullet.

<comment><USER2> Fully grown decision trees are notorious for their risk of overfitting your training set. If you're uncomfortable fully growing the trees, you then have to consider whether you want to grow them out completely and then prune them, stop growing after a specific depth, train the trees using a random subset of features in the feature space (and then how many do you select? Do you use the square root? Logarithm?), etc. Even then, what are you using to choose when a node splits? Information gain? Information gain ratio? Gini index? What about when you have a feature like credit card numbers, which are unique?

These are all choices that the user has to make. For something as seemingly simple as a decision tree, you can see why _some_ knowledge is required before embarking on any machine learning mission.

</comment></comment></comment><comment><USER6> Great! I was just investigating AlchemyAPI and OpenCalais this weekend. I look forward to trying TextMinr.

TextMinr seems like a combination of those services along with the idea of 80legs.com? Is that correct?

<comment><AUTHOR> I'm not familiar with 80legs, but the main idea is to "democratise" access to this technology and make it easily accessible to anyone who wants to build something on it.

The initial few beta releases will probably be aimed at people aiming to build applications themselves by providing them with API's, but hopefully we'll build out the analytics side of things soon enough so it becomes accessible to non-techies as well.

</comment></comment><comment><USER7> I'm really happy to see more people moving into this space.

I've used a number of different systems (openCalais, AlchemyAPI, Zemanta...) in a variety of projects (Sentiment analysis, document classification...), and what I've found thus far is that while each system works extremely well within some restricted application classes, none come close to being general purpose APIs for the myriad applications developers try to throw at them.

A couple of pain points I've encountered are requiring a larger than expected corpus to generate meaningful data based on overly broad scope of the platform's analysis, or the lack of ability to apply negative signals from external sources. I find there tends to remain a large quantity of logic sitting rather redundantly on the application end to post-filter what's generated.

I don't pretend to understand the level of complexity involved or what's being worked on currently (not an NLP guy), but I do think there's a huge space to create publicly available text mining which can more effectively be applied to narrow domains.

</comment><comment><USER8> Machine learning seems to be a meme on the rise right now. What kind of startups are possible in that domain?

<comment><USER9> self driving cars

autonomous helicopters

automated analysis of satellite imagery

search engines

visual search engine (google goggles)

virtual assistant (siri)

speech recognition

document classification (spam detectors)

question answering systems (ibm watson)

ad placement (google adsense)

computer guided surgery

high throughput imaging (chemo/bioinformatics)

product recommendation (amazon/netflix)

acturial science

industrial automation (inspection systems)

intelligent video surveillance

<comment><USER10> I got most of these right away, but could you expand on what you mean by "high throughput imaging (chemo/bioinformatics)"?

<comment><USER11> The high throughput imaging that I'm familiar with is in regards to cell imaging. Cells are cultured in high-density plates (96-well or 384-well dishes), each well is given a different experimental condition (drugs, RNAi, etc) and then imaged on an automated microscope.

As you can imagine, this generates tons of data. Our lab did a highthrouput screen of genetic mutants in neurons, and then used software to quantify basic morphology such as neurite length , arborization, and cell death.

Crystallographers will use a similar system to bathe their protein in billions of compounds to find the right combination for crystallizing. Automated cameras will capture images and try to identify which ones have crystallized so the researcher doesn't have to do it by hand.

</comment></comment></comment></comment><comment><USER12> This would really be useful on many, many levels. Why has this access to such data been so roped-off?

</comment><comment><USER13> I've found in my data-mining experience that the most interesting data (at least on the Web) is not particularly easy to parse, even if you write something that automates a form's POST submissions. The second difficult part is normalizing it, as much web/text data is formatted for _display_ to humans, which is quite different than data in easily analyzable form.

So given that, it's just worth learning enough program to do loops, conditionals, and regexes to get what you want.

<comment> St-Clock This is so true. I've been mining mailing lists and framework documentation for my Ph.D. and most of my effort and time was spent normalizing the data. Once that was done, classifying content and linking concepts was relatively easy...

</comment></comment><comment><USER9> This probably won't work, as google found out with it's prediction api (it hasn't been used much). There's already enough open source software out there that's state of the art and easy to use.

There's good business to be had in selling data though which is where these folks should probably divert their effort.

<comment><USER14> I don't know; ML has a lot of applications and the bar for most people to be able to implement it is rather high. Lowering the bar so "mere mortals" can have some serious infrastructure and data that's a mere API call away seems pretty huge.

<comment><USER9> The problem is that if you're not confident enough to get these systems working yourself, you're probably not going to be confident enough in your business to pay by the sip for someone else's api.

</comment></comment></comment><comment><USER15> I honestly don't think this is feasible without regular expressions. There's very many minor details that make data mining work which have to be custom tailored to different solutions.</comment>


Ask HN: Someone liked one of my photos on Facebook. Friends only. but she is not - <AUTHOR>

Someone managed to like a photo I've uploaded. I checked out her profile, but she is not a friend with me or mutual friend of anyone.. Anyway she liked a funny picture I've uploaded as a photo, and now i'm confused. The pic is uploaded with privacy setting "Friends except acquaintances".
Is there any FB exploit roaming around that I'm not aware of or is this some funky bug? Maybe some privacy stuff I am unaware of?
http://i.imgur.com/b8LJmO6.png <comment><AUTHOR> Pic or it didn't happen:

(Obviously I sent out the friend request after I saw it). No friends, no mutual, whole different country..

/edit Second one, where you can see the privacy setting. And for more fun I left the URL unsmudged. So you can now all like my pic(?)

/edit2 woops.. [http://i.imgur.com/b8LJmO6.png](http://i.imgur.com/b8LJmO6.png)

<comment><USER2> Your "pic" also shows us half a dozen of your friend's names (in the right column) and one conversation mini-window (at the bottom, in Dutch) under the Facebook overlay.

I advise you crop/blur those parts.

<comment><AUTHOR> Thanks for the heads-up. I always miss something gah :)

</comment></comment></comment><comment><USER3> That sounds like a worse version of a bug my wife found. She uploaded a vacation bikini pic set to friends only. Her friend liked the pic, and was friends with my wife's coworker. All of her coworkers saw the bikini pic. In your case this person has no connection at all.

<comment><USER4> Could somebody with a better understanding of how Facebook works explain how this happens? Is it unexpectedly difficult to implement some sort of whitelist or something?

<comment><AUTHOR> I've sent an inquiry to FB. (Report problem>privacy ) Not that I expect anything to come out of it.

</comment></comment></comment><comment><USER5> Is it possible for Tanja to have seen the photo in Ticker from a mutual friend who liked your photo? Or does Ticker adhere to the privacy restriction as well?

<comment><AUTHOR> But wouldn't I have a "x mutual friend(s)" displayed on Tanja her profile page, if we would have a mutual friend?

</comment></comment><comment><USER6> Is it possible you had a mutual friend, and either she unfriended them, or she got unfriended?

You can try asking her, maybe she knows how it happened.

</comment><comment><USER7> Maybe one of your friends tagged her in the photo. This would allow her to see it. I think it would allow her to "Like" it as well.

<comment><AUTHOR> But I would see that tag, no?</comment></comment>