Heuristics that almost always work • Hacker News Board

Re: Heuristics that almost always work

#481

Post by NoPie » Wed, Feb 09, 2022, 12:02 PM UTC

ccalloway wrote: post #460

inglor_cz wrote: post #30

This story reminded me of a story written by a Czech biologist who studied animals in Papua-New Guinea and went to a hunt with a group of local tribesmen. The dusk was approaching, they were still in the forest and he proposed that they could sleep under a tree. The hunters were adamant in their refusal: no, this is dangerous, a tree might fall on you in your sleep and kill you . He relented, but silently considered…

It seems like 1:5000 is not an accurate probability, but just a number which he chose in order to convince himself that sleeping under a tree was not a risky activity. But he chose a bad number and later realized that an argument based on that number was not convincing. If the chance was actually 1:5000, the longevity of trees would be similar to that of hunters sleeping under them - or lower, since hunters can somet…

Even if it is, no one suggested that local hunters sleep every night in the forest. If they happen to sleep under the tree once in a year, it won't increase their risk of death significantly.

There could be another reason why sleeping in the forest was dangerous – e.g., poisonous snakes or dangerous animals etc. Also if the temperature drops at night and they didn't have enough clothing, they could get hypothermia and so on.

Re: Heuristics that almost always work

#482

Post by krick » Wed, Feb 09, 2022, 12:13 PM UTC

ccalloway wrote: post #460

inglor_cz wrote: post #30

This story reminded me of a story written by a Czech biologist who studied animals in Papua-New Guinea and went to a hunt with a group of local tribesmen. The dusk was approaching, they were still in the forest and he proposed that they could sleep under a tree. The hunters were adamant in their refusal: no, this is dangerous, a tree might fall on you in your sleep and kill you . He relented, but silently considered…

It seems like 1:5000 is not an accurate probability, but just a number which he chose in order to convince himself that sleeping under a tree was not a risky activity. But he chose a bad number and later realized that an argument based on that number was not convincing. If the chance was actually 1:5000, the longevity of trees would be similar to that of hunters sleeping under them - or lower, since hunters can somet…

How did he even come up with these numbers, anyway?

Re: Heuristics that almost always work

#483

Post by env123 » Wed, Feb 09, 2022, 12:25 PM UTC

99.9%% correct heuristic/0.1% role value is a stretch. The author only gave an arbitrary number to make a point.

Everybody knows 80% correct heuristic/20% role value is more realistic.

- said the contrarian

Re: Heuristics that almost always work

#484

Post by coldtea » Wed, Feb 09, 2022, 12:37 PM UTC

borroka wrote: post #275

I read them as sloppy caricatures that provide little value to the conversation. Let's take the security guard: "The only problem is: he now provides literally no value. He’s excluded by fiat the possibility of ever being useful in any way. He could be losslessly replaced by a rock with the words “THERE ARE NO ROBBERS” on it." That is blatantly not true, the guard provide value since the wanna-be robbers don't know w…

>I read them as sloppy caricatures that provide little value to the conversation.

That about sums up the whole movement AstralCodex is part of.

Re: Heuristics that almost always work

#485

Post by coldtea » Wed, Feb 09, 2022, 12:43 PM UTC

thatjoeoverthr wrote: post #438

borroka wrote: post #370

Earlier quoted context omitted.

"On your doctor take, you do know that the other author of this post is a licensed and practicing Physician, right?" -- Your observation is indeed much more interesting than the whole article, since it shows a reasonable (and not a caricature with zero value) heuristic. You are saying that I (who may or may not be a physician, but for argument's sake let's say I am not) should not have an opinion that is different, w…

In other words, your doctor could have been losslessly replaced with a rock that says “apply a steroid cream”, and that heuristic would have harmed you.

If it had benefited thousands of others, does it matter in the larger view?

The naive alternative is the doctor always spending time to get to more nuanced advice, that will be more often than (every time the rock was as good) a waste of resources (time/money/opportunity cost), and which in a lot of cases would also be more harmful (iatrogenic harm) than the rock advice.

"But, why 'always'? It's enough that the doctor goes for more nuance when he sees a reason to!", you'll say.

Well, that's what doctors actually do. They are not glorified rocks, they are bimodal (rock mode vs looking deeper mode) - and they're most rock because (even if the miss a few 'loop deeper' cases) because it's way more efficient than the alternative (always or mostly non-rock, that is, digging deeper without first seeing strong indications that they should dig deeper).

Re: Heuristics that almost always work

#486

Post by wizzwizz4 » Wed, Feb 09, 2022, 12:45 PM UTC

Someone wrote: post #440

pessimizer wrote: post #108

Earlier quoted context omitted.

If you'll die if a roll of three dice comes up sixes, you're not really in a lot of danger. If you do it every day, you have about 15 months to live.

The expected value will be 6³ = 216 days or about 7 months. Where do you get the factor of two from? Also, “not really in a lot of danger”? Those odds are worse than that of a 100 year old in the USA (they have a life expectancy of over two years) Certainly, as an additional risk, it’s high.

You forget: once you roll three 6s in a row, you're dead, and you don't roll any more. Your expected calculation assumes that people keep rolling after they get 666.

Though I'm not sure where they got their figure from, because there isn't an “expected time to live”; there's a 90% probability to live time, a 5% probability to live time…

Re: Heuristics that almost always work

#487

Post by canadian_castor » Wed, Feb 09, 2022, 1:01 PM UTC

I see this more as intuition than a heuristic. If your are in a field where everything is OK 99.9% of the time, you can't help but have an intuition that there will never be any problems. Correct intuition needs to be fed positive and negative outcomes to be well balanced. If you are in a field where intuition is biaised, dont use it, rely only on data.

Re: Heuristics that almost always work

#488

Post by lelandfe » Wed, Feb 09, 2022, 1:12 PM UTC

ccalloway wrote: post #460

inglor_cz wrote: post #30

This story reminded me of a story written by a Czech biologist who studied animals in Papua-New Guinea and went to a hunt with a group of local tribesmen. The dusk was approaching, they were still in the forest and he proposed that they could sleep under a tree. The hunters were adamant in their refusal: no, this is dangerous, a tree might fall on you in your sleep and kill you . He relented, but silently considered…

It seems like 1:5000 is not an accurate probability, but just a number which he chose in order to convince himself that sleeping under a tree was not a risky activity. But he chose a bad number and later realized that an argument based on that number was not convincing. If the chance was actually 1:5000, the longevity of trees would be similar to that of hunters sleeping under them - or lower, since hunters can somet…

https://pubmed.ncbi.nlm.nih.gov/6502774/

There’s a real dearth of info around coconut fatalities. This 1984 paper examined a 4 year timespan of all trauma-related admissions to one hospital in Papua New Guinea. 9 of them (2.5% overall) stemmed from coconuts. In 3 of the cases, all children, the patients slipped into coma.

From what I’ve read elsewhere (no good links, sorry), coconut injuries worldwide seem to have fallen significantly due to better harvesting practice - the age of a coconut and their chance of falling appear to be linked. While I can’t find a good paper saying this, I do buy it.

So, perhaps not 1:5000, but (at least at one point in time) definitely a risk.

Re: Heuristics that almost always work

#489

Post by necovek » Wed, Feb 09, 2022, 1:18 PM UTC

stavros wrote: post #443

ArcMex wrote: post #416

Earlier quoted context omitted.

I generally take off my jacket before driving for that very reason.

Luckily newer cars won't stop beeping if you forget your seatbelt, so the problem is mitigated. Not so for parachutes, apparently.

To be honest, I never wear a parachute when driving!

Re: Heuristics that almost always work

#490

Post by pugets » Wed, Feb 09, 2022, 1:20 PM UTC

derbOac wrote: post #156

kbuchanan wrote: post #35

Earlier quoted context omitted.

It's a great example. This is the very reason I have scaled back the amount of time I rock climb as I've gotten older -- not because any individual outing is dangerous, but there's an element of Russian roulette wherein the mere act of doing it more often dramatically changes the risk.

"There are bold X, and old X, but no old, bold X." Replace X with any practitioners subject to sufficient risk as a result of their practice. I first heard it in the context of mushroom foraging.

This line is famous in aviation, where X = pilots