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Heuristics that almost always work

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Re: Heuristics that almost always work

#321

Post by twobitshifter »

jrochkind1 wrote: post #157
twobitshifter wrote: post #136

Earlier quoted context omitted.

True but it would be incorrect to assume that you can safely keep basejumping every day in a year, just because you haven’t died in the last 50 days. Eventually the stats say you will be 87% likely to have an accident when you consider your choice at the beginning of the year. It might be day 20 or day 300, but you won’t know what case you end up in. The chance of your next jump being your last is always the same, bu…

Not exactly. If you've done it 50 days without an accident, your current chances of the accident happening in the remainder of the year are NOW less than 87%. If you've made it Jan 1 to July 1 months without an accident, the chances of you making it to Dec 31 are now better than they were on Jan 1 -- because now they are just the chances of you making it six months, not a year. The chances of flipping 6 heads in a ro…

I meant to say starting a new year after the 50 past days, I see that wasn’t clear though.

Re: Heuristics that almost always work

#322

Post by bluGill »

timClicks wrote: post #211
derbOac wrote: post #156

Earlier quoted context omitted.

"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.

The risks are highest when learners are at a beginner to intermediate stage. They know the basics, and have gained some confidence, but don't know enough to get themselves out of trouble. This is called Stage 1 in the Gordon Model of learning: unconscious incompetence.

No, the risks are greatest when you reach complacency. Beginners, even bold ones, take some care. You mostly see this in things like forklift drivers because it takes years of doing the same thing every day before you really get expert enough to be complacent

Re: Heuristics that almost always work

#323

Post by jancsika »

crent wrote: post #199
dwohnitmok wrote: post #183

The last sentence of the edit the author provides is the key insight of this piece. > the existence of experts using heuristics causes predictable over-updates towards those heuristics. That's the essence of this piece. If you expect that consultation with experts will leave you with a more accurate picture of things than before consultation, you should first be sure that their heuristics are not equivalent to readin…

Which is the rub, right? How can a non-expert reasonably come to a conclusion of whether or not an expert's prediction is baseless or is actually solid/insightful?

By getting a second or third opinion, no?

Re: Heuristics that almost always work

#324

Post by quickthrower2 »

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…

Perhaps sleeping under a tree is the "not putting on your seatbelt" of the jungle.

Re: Heuristics that almost always work

#325

Post by kirrent »

PragmaticPulp wrote: post #281
pards wrote: post #131

The doctor rings true. I had 3 separate doctors on 3 separate occasions diagnose my 21 month old son with an ear infection, instead of the plum-sized malignant brain tumour that it was. From their point of view, pediatric brain tumours are very rare and ear infections are common. Their 99% heuristic almost killed him. That was 2010. He survived and is now a vibrant 13 year old, but only because of one curious intern/…

> The doctor rings true. I had 3 separate doctors on 3 separate occasions diagnose my 21 month old son with an ear infection, instead of the plum-sized malignant brain tumour that it was. This one is difficult. The first doctor with the first diagnosis was likely doing the right thing. Although tragic, it's exceedingly rare for someone that young to present with a brain tumour. If a doctor was ordering CT scans every…

Exactly, the post is a Scott Alexander post so he'd never object to the concept of priors. There's nothing wrong with having a strong prior that the volcano's not going to blow up this year, that it's just the wind not a break-in, or that it's most likely an ear infection with a tumour so unlikely as to not be worth the radiation risk and cost of a CT.

Really, the article is about people who don't bother to monitor the likelihood that updates their prior because the prior is so damn explanatory anyway. But, a doctor treating an ear infection isn't doing this because the act of treatment is also a test. It's not the 'did the volcano erupt' or 'did we get burgled' test with huge downsides because even if there's a serious underlying issue a week or two is unlikely to change too much. If the purported infection doesn't clear up then it's time for the doctor to update their prior and reconsider what investigations or treatment options are now appropriate. Even better than taking your history to your next doctor, keep seeing the same doctor.

Re: Heuristics that almost always work

#326

Post by ska »

epolanski wrote: post #287
vincentmarle wrote: post #152

Earlier quoted context omitted.

This is called ergodic theory, the more you repeat an action that could result in catastrophe, the likelihood of that catastrophe occuring will be close to 100% if the number of events is high enough.

But that doesn't imply any higher probability. Say chance of dying when doing alpinism is one in a thousand. The 1000th time you go climbing the chances of dying are still 1/1000. If you get 100 heads in a row, the 101th time you launch a coin the chance of getting heads is still 50%.

Right, but it's easy to conflate two very things here:

"What are my chances of dying in a climbing accident", and

"What are my chances of dying today if I go climbing".

If you are on a plane, you* have a lower risk of some kinds of cancer than the airline staff do. This has nothing to do with the flight you are both on, and everything to do with accumulated flights

"you*" = for most people, i.e. barring a counteracting risk factor.

Re: Heuristics that almost always work

#327

Post by quickthrower2 »

kadoban wrote: post #87
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…

Is 1:5000 an actually good assessment? I'd suspect it's very much not, especially if you avoid obviously dead trees and maybe move if a storm comes.

Not an expert on this, but I suspect you wouldn't want to move camp during the night if you can avoid. Especially in the rain.

Re: Heuristics that almost always work

#328

Post by TameAntelope »

Symmetry wrote: post #286
TameAntelope wrote: post #215

Oh man, next time I need an illustration of how the "villians/heroes" narrative can completely destroy any complexity in a human being, I now have a very well written example! These people don't exist. Not a single one. Every time you're tempted to think someone fits one of these roles, remember how complex you are, and then think about how complex you likely appear to others. The rift you can see between your intern…

I finished the piece noticing times that "heuristics that almost work" were a genuine temptation for me to adopt and having more empathy for people who end up adopting them. If you really don't feel like you could ever be tempted to become lazy in the way that the piece illustrates then I admire your integrity but there are actually many of us who are tempted to reduce the rigor with which we investigate things when…

The mere fact that you think of using these kinds of heuristics as "lazy" and "acting without integrity" is itself an example of why this article creates a moralistic dichotomy that's both completely untrue and entirely unnecessary.

Don't fall for it. Laziness is a lot rarer than you may believe, even in yourself. People don't just "do bad things" very often for the sake of doing bad things, there are almost always reasons beyond the obvious.

Re: Heuristics that almost always work

#329

Post by kelnos »

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 agree with your take on the doctor heuristic. But there is also the worry that the patient won't call back for longer than they should, and the underlying disease could have a chance to get a lot worse in that time. If a doctor really isn't doing any basic diagnostic work, and is just telling people "take some aspirin, and call back if it doesn't go away after X days", that is still IMO negligent. If I have cancer, I don't want to wait 2 weeks or a month longer than necessary to start treatment. That could be the difference between life and death.

On the security guard, you're right, but I think it's still interesting to think about. If the security guard really does just assume any noise heard is not robbers, then they are effectively not doing anything. Their deterrence value is non-zero, agreed, but maybe it's cheaper and more productive to install motion-activated security cameras at ingress points, and big honkin' signs at the perimeter that say "Security monitoring in effect 24/7". Yes, you have to pay for the monitoring, but that's probably cheaper than paying for a butt-in-seat. And safer, too! Most security guards at most places probably aren't trained for much beyond the basics. I think it's more likely than not that someone will get hurt if robbers do show up and a security guard gets involved. I would much rather some stuff get stolen than people get hurt. (Certainly there are some things that are critical enough that require a well-trained security force. I just think these things are less common than most people would think.)

> Un-nuanced and quite sloppy presentation of heuristics.

I think the lack of nuance is in part the point. We should be examining places in our lives where we go by our gut feeling, or by the common case, when we probably should actually be doing research, diagnosis, or testing. Even if the results aren't as dire as some of the non-nuanced takes, they're still bad enough to warrant some thought.

Re: Heuristics that almost always work

#330

Post by s1artibartfast »

bmc7505 wrote: post #219

"Fifty thousand years ago there were these three guys spread out across the plain and they each heard something rustling in the grass. The first one thought it was a tiger, and he ran like hell, and it was a tiger but the guy got away. The second one thought the rustling was a tiger and he ran like hell, but it was only the wind and his friends all laughed at him for being such a chickenshit. But the third guy though…

Context for the pedants:

This is dialog from a sci-fi novel about aliens and space vampires. It is figurative language to illustrate a concept.

Great novel full of evolutionary psychology trivia:

https://en.wikipedia.org/wiki/Watching-eye_effect

https://www.newscientist.com/article/dn9424-big-brother-eyes...

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