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Heuristics that almost always work

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Re: Heuristics that almost always work

#501

Post by kenjackson »

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%.

This is exactly why people who do high risk think it will never happen to them.

Re: Heuristics that almost always work

#502

Post by mrfusion »

bluGill wrote: post #322
timClicks wrote: post #211

Earlier quoted context omitted.

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

I call that the rattlesnake principle. Treat all dangerous tasks like you’re dealing with a rattlesnake.

Re: Heuristics that almost always work

#504

Post by Steltek »

fastball wrote: post #390
dragontamer wrote: post #332

Earlier quoted context omitted.

The Hydroxychloroquine discussion is pretty bad as well. We were confidently against Hydroxychloroquine because it was well tested in the RECOVERY trial in June 2020 [1]. The time to be optimistic was during the trial-phase of the test. Once that time passed, everything beyond that point was unnecessary and unhelpful hype. ------ What's amazing to me, is that the RECOVERY trials showed that Dexamethasone cut the deat…

I think you missed the point. The idea here is that there were people that said before any results were in that hydroxychloroquine was not gonna work, operating with a heuristic that almost always works. And in this case they were correct, which the article doesn't seem to disagree with. The point is that at some point the heuristic will fail, not that it did in the case of hydroxychloroquine.

"Extraordinary claims without evidence or rationale are bogus" as a heuristic seems pretty good to me?

When presented with a problem and infinite solutions, you need to start narrowing down which paths to investigate somehow. Come back with evidence and the conversation goes further.

Re: Heuristics that almost always work

#505

Post by ptha »

bluGill wrote: post #322
timClicks wrote: post #211

Earlier quoted context omitted.

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

I'm reminded of Louis Slotin experimenting with the "Demon" core. The core was surrounded by 2 half spheres of beryllium. The core would go critical if the 2 spheres were not separated from each other.

The standard protocol was to use shims between the halves, as allowing them to close completely could result in the instantaneous formation of a critical mass and a lethal power excursion. Under Slotin's own unapproved protocol, the shims were not used and the only thing preventing the closure was the blade of a standard flat-tipped screwdriver manipulated in Slotin's other hand. Slotin, who was given to bravado, became the local expert, performing the test on almost a dozen occasions, often in his trademark blue jeans and cowboy boots, in front of a roomful of observers. Enrico Fermi reportedly told Slotin and others they would be "dead within a year" if they continued performing the test in that manner. Scientists referred to this flirting with the possibility of a nuclear chain reaction as "tickling the dragon's tail", based on a remark by physicist Richard Feynman, who compared the experiments to "tickling the tail of a sleeping dragon".

On the day of the accident, Slotin's screwdriver slipped outward a fraction of an inch while he was lowering the top reflector, allowing the reflector to fall into place around the core. Instantly, there was a flash of blue light and a wave of heat across Slotin's skin; the core had become supercritical, releasing an intense burst of neutron radiation estimated to have lasted about a half second. Slotin quickly twisted his wrist, flipping the top shell to the floor. The heating of the core and shells stopped the criticality within seconds of its initiation, while Slotin's reaction prevented a recurrence and ended the accident. The position of Slotin's body over the apparatus also shielded the others from much of the neutron radiation, but he received a lethal dose of 1,000 rad (10 Gy) neutron and 114 rad (1.14 Gy) gamma radiation in under a second and died nine days later from acute radiation poisoning.

https://en.wikipedia.org/wiki/Demon_core#Second_incident

Re: Heuristics that almost always work

#506

Post by gilbetron »

zmmmmm wrote: post #448
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.

I took the same approach with motorcycling. I decided to do it for 3 years while at university because it had a transformative impact on my lifestyle. But I also decided the odds were way too bad to keep doing it my whole life. So I stopped and haven't done it since then.

I only owned a bicycle for several years at the same age, and have since mostly used a car to get around. I've been in various, relatively minor accidents with both, and have always wanted to try using a motorcycle, but it seems to take the risks of both biking and driving and puts them together!

Re: Heuristics that almost always work

#507

Post by DiggyJohnson »

AlanYx wrote: post #164
DiggyJohnson wrote: post #23

Great article, really enjoyed it. I second the Talib connection. But anyways... Does anyone else struggle with Substack's typeface, specifically it's width and spacing between characters? I'm a bit of a typeface nerd, and I genuinely like or enjoy most of our common fonts. Substack is the only site that I find the typeface to significantly affect the reading experience.

I tend to agree with you about the typeface they use, Spectral. I think it's a combination of factors: loose tracking designed to permit slightly over-emphasized differences in weight (which were a design goal for the font) and somewhat selective replacement of inktraps from the inspiration face (Elzévir) with angular serifs, which creates a bit of a visual discordance. I don't find it unreadable, personally, but it…

Very well put. I agree with your analysis. There's a lot of things I like about Spectral, and in general I like the "genre" of faces that it belongs to. The loose tracking+over-emphasized font weights is the core of my challenge.

Re: Heuristics that almost always work

#508

Post by gilbetron »

Jupe wrote: post #291
jozvolskyef wrote: post #264

Earlier quoted context omitted.

It is a tough call this one. If my calculations are correct, based on data from[1], male infant head CT scans cause one excess death per ~3k scans. There must have been something else than a remote possibility to warrant ordering it. [1]: https://www.ajronline.org/doi/full/10.2214/AJR.12.10294

I interpret the linked article different. Can you elaborate? For example (from the summary): =============================== "CONCLUSION. Radiation exposure from the use of CT in the evaluation and management of severe traumatic brain injury causes negligible increases in lifetime attributable risk of cancer and cancer-related mortality. Treating physicians should not allow the concern for future risk of radiation-in…

You need to read those things literally. It doesn't mean CT scans should be used whenever a doctor thinks. It means that a doctor evaluating a TBI should be ok with using it. Basically, the odds switch when there is an additional symptom that there is something wrong with the head.

Re: Heuristics that almost always work

#509

Post by gilbetron »

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/…

Running a CT scan on every kid suffering from ear pain is a bad idea, not only economically, but from the negative effects of radiation exposure to so many kids.

I know in your head the scenario was "were it not for that one person, my kid would've died", but the more likely scenario was, "the symptoms got worse and then a doctor decided it was enough to warrant another look and the tumor was detected, surgery was performed, and my son was ok". It was wonderful that it was caught when it was, but odds are very high your son would've still been ok even if it had been caught over the next several weeks.

Also, I'm very relieved to hear your son is ok, as a father of a 13 year old son, you lived through a nightmare!

Re: Heuristics that almost always work

#510

Post by PaulHoule »

Litost wrote: post #480
throw1234651234 wrote: post #342

Earlier quoted context omitted.

There is also something called "Normalization of Deviance", defined better by a quote: "Today, the term normalization of deviance — the gradual process by which the unacceptable becomes acceptable in the absence of adverse consequences — can be applied as legitimately to the human factors risks in airline operations as to the Challenger accident." * Most of you have probably heard of it in the context of fighter pilo…

Thanks for posting these, I'd only seen Normalisation of Deviance mentioned in these two youtube videos by Mike Mullane and never thought to look any further: https://www.youtube.com/watch?v=Ljzj9Msli5o https://www.youtube.com/watch?v=jWxk5t4hFAg and the uploader references some further links: https://www.fireengineering.com/leadership/firefighter-safet... https://www.flightsafetyaustralia.com/2017/05/safety-in-mind.…

Vaughn's book The Challenger Launch Decision doesn't tell this truth: the root cause of the accident can be traced back a decade to the acceptance of a design that was "unsafe at any speed".

Every other manned space vehicle had an escape system. The crew of the Challenger was not killed by the failure of the SRB or the explosion of the external tank, but rather when the part of the orbiter they were in hit the ocean. They could have build this into a reinforced pod with parachutes or some other ability to land but they chose not to because they wanted to have the payload section in the rear.

In the case of Columbia it was the fragile thermal protection system that did the astronauts in. There was a lot of fear in the first few flights that the thermal tiles would get damaged and failed and once they thought they'd dodged that bullet they didn't worry about it so much.

"Normalization of deviance" was a formal process in the case of the space shuttle of there being meetings where people went through a list of a few hundred unacceptable situations that they convinced themselves they could accept, often by taking some mitigations.

When the design was finalized it was estimated that a loss of vehicle and crew would happen about 2%-3% of the the time which was about what we experienced. (Originally they planned to launch 50 missions a year which would have meant the continuous trauma of losing astronauts and replacing vehicles.)

It's easy to come to the conclusion that it was a particular scandal that one particular concern got dismissed during a "normalization of deviance" meeting but given a poorly designed vehicle it was inevitable that after making good calls for thousands of concerns there would be a critical bad call.

"Normalization of deviance" is frequently used for a phenomenon entirely different than what Vaughn is talking about, something informal that happens at the level of individuals and small groups. That is, the forklift operators who come to the conclusion it is OK to smoke pot at work, the surgeon who thinks it is OK to not wash his hands, etc. A group can pressure people to do the right things here, but it's something different from the slow motion horror of bureaucracy that tries to do the right thing but cannot.

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