14 ms·

When U.S. air force discovered the flaw of averages (2016)

273 points by elorant 7y ago

pintxo 7y ago
> any system designed around the average person is doomed to fail. Daniels published his findings in a 1952 Air Force Technical Note entitled The “Average Man”?
- barbegal 7y ago
  Which you can read here https://apps.dtic.mil/dtic/tr/fulltext/u2/010203.pdf https://apps.dtic.mil/dtic/tr/fulltext/u2/010203.pdf
war1025 7y ago
Thought this sounded familiar then realized it's a book review for a book I read a few years back. It was an interesting book. Recommend it to anyone who finds the article interesting.
duxup 7y ago
I wonder if this applies to something like performance reviews where measuring overall performance as something relative to 'average' inevitably doesn't make sense to anyone as perhaps there is no average there for a job with any level of complexity.
JoeAltmaier 7y ago
Been noted here on HN: the average web form excludes lots of people. Lots of folks cant fill in: First/middle/last name; unique username/password; social security number; street address; bank account. And not just folks in Micronesia or whatever. Heck my business partner hasn't got a deliverable street address - no mailbox at his house. He has a PO box. Is a nightmare getting Amazon deliveries that aren't lost, or left in the bushes, or returned undeliverable. Anyway, yes, there is no average person.
- astrea 7y ago
  The name field situation has never bothered me as a typical American with the standard name format, but as I've grown and met people from different cultures I've learned just how frustrating that part of forms can be. Even (or rather, especially?) government forms are terrible about this.
  - NickM 7y ago
    Even typical Americans struggle with this sometimes if they have, say, hyphenated last names. I've encountered plenty of software out there that will reject or fail on even such a common case as this.
- jbay 7y ago
  There's so many times that an ostensibly international website has rejected me because I don't have a US-formatted numerical zip code. Even when they have a country field.
lalaithion 7y ago
Note that this is not some sort of unexpected effect due to humans not behaving mathematically ideally; this is what happens when your intuitions about 1, 2 and 3 dimensions are applied to higher dimensional spaces. Consider the goal of being in the middle 50% of a random value on one dimension; you have a 50% chance. But if you have two dimensions, and you want to be in the middle 50% for both of them, it's a 25% chance. And if you have 3, it's a ~12% chance. This already is counterintuitive, but when you ramp it up to 10 dimensions, it's a ~0.01% chance. That means that if you have a thousand people, only one of them (on average) will be in the middle 50% of all of them. Even the praised end state of the air force, with 9 dimensions and a required support of 90% of individuals of each dimension, implies that only 38% of individuals will be supported overall. (Granted, human dimensions aren't wholly uncorrelated.)
- stygiansonic 7y ago
  Great explanation. This is an example of the curse of dimensionality. An intuitive way to think about this is that each dimension you add is another “chance” for one of them to fall outside of the range. Another way to think about it is the often-cited unit n-dimensional sphere. If you were to uniformly sample points from within this n-dimensional sphere, as n increased, the proportion of points lying near the surface of the sphere would increase.
  - Balgair 7y ago
    Numberphile has a good one on how these things can get crazy quickly: https://www.youtube.com/watch?v=mceaM2_zQd8 https://www.youtube.com/watch?v=mceaM2_zQd8
- 6gvONxR4sf7o 7y ago
  I find it more intuitive to to discard the spatial intuition and think in terms of events. You want something in the X% norm? Think about it like a X%-heads biased coin flip. If you flip it enough times, it'd be shocking to get all heads. Even if the coin flips (dimensions) are correlated, many coin flips (dimensions) means at least some tails (dimension outside the norm).
- 7y ago
leephillips 7y ago
This is a really interesting article. The most fascinating part is to learn that the AF actually listened to the man and changed their policies. This kind of thing can happen even when only measuring a single dimension, if the distribution is multimodal. If everyone is either really short or really tall, then nobody will be near the average height.
- macintux 7y ago
  I realize that the audience is quite different, but it’s interesting to compare the response to “no woman matches our expectations” (means they’re fundamentally broken) vs “no man matches our expectations” (means the model is fundamentally broken).
RcouF1uZ4gsC 7y ago
> Out of 4,063 pilots, not a single airman fit within the average range on all 10 dimensions. > Less than 40 of the 3,864 contestants were average size on just five of the nine dimensions and none of the contestants — not even Martha Skidmore — came close on all nine dimensions. This seems more an issue of the "curse of dimensionality"[0] more than the "flaw of averages". Be very wary when you are trying to draw conclusions from a dataset with many dimensions. 0. https://en.wikipedia.org/wiki/Curse_of_dimensionality https://en.wikipedia.org/wiki/Curse_of_dimensionality
- ken 7y ago
  I don’t think so. They also said: > Even more astonishing, Daniels discovered that if you picked out just three of the ten dimensions of size ... less than 3.5 per cent of pilots would be average sized on all three dimensions.
  - Someone 7y ago
    FTA: ”These formed the dimensions of the “average pilot,” which Daniels generously defined as someone whose measurements were within the middle 30 per cent of the range of values for each dimension.“ 0.3³ = 0.0027 = 2.7%, so if those measurements are independent of each other, it isn’t surprising that he found “less than 3.5 percent”.
    - Retric 7y ago
      I think the general assumption is arm length and height for example are strongly correlated.
    - Worker32850 7y ago
      Human dimensions are closer to a normal distribution. (Not quite normal, but let's pretend.) In that distribution then 46% of subjects should be in the middle 30% of 3 dimensions. [0] [0] With 4000 subjects they presumably have all sizes within ~3.5 stddevs represented. The middle ~1.2 stddevs should hold ~77% of the population. 0.77^3 = ~46%
clircle 7y ago
Even with just one dimension, the average may not be characteristic of the population.
tinalumfoil 7y ago
This interesting but all a bit wordy and meandering. Tldr: The air force was using the average dimensions of their pilots to design aircraft. Coincident to this, there was a large number of downed planes questionably attributed to "pilot error" but that many believed to be from an unknown cause. A recruit from Harvard charged with collecting data on pilots realized few people were close to the average, and recommending cockpits be fit to each individual. The AF took the recommendation and eventually companies produced aircraft with adjustable seating and cockpits. Tldr tldr: dont just reach for the average
- jimhefferon 7y ago
  > meandering I know. Isn't that wonderful?
AdrianB1 7y ago
This is a duplicate, see https://news.ycombinator.com/item?id=11230287 https://news.ycombinator.com/item?id=11230287, https://news.ycombinator.com/item?id=16220499 https://news.ycombinator.com/item?id=16220499 and more.
CalChris 7y ago
This reminds me of an old math joke. A statistician and a mathematician went duck hunting. From a blind, the mathematician shot and hit a duck. Their retriever went and got the duck. Then the statistician spotted and shot at another duck but shot too high. Quickly the statistician shot again but too low. The statistician then beamed with pride, on average, that's a dead duck.
ethbro 7y ago
The USAF employs averages in all kinds of interesting ways! "How US nuclear force modernization is undermining strategic stability: The burst-height compensating super-fuze" (or: How I Learned to Stop Worrying About Undershoot and Love Terminal Detonation Timing) https://news.ycombinator.com/item?id=16642280 https://news.ycombinator.com/item?id=16642280 (2018)
def8cefe 7y ago
>The Aero Medical Laboratory hired Daniels because he had majored in physical anthropology, a field that specialized in the anatomy of humans, as an undergraduate at Harvard. During the first half of the 20th century, this field focused heavily on trying to classify the personalities of groups of people according to their average body shapes — a practice known as “typing.” For example, many physical anthropologists believed a short and heavy body was indicative of a merry and fun-loving personality, while receding hairlines and fleshy lips reflected a “criminal type.” Can anyone point me in the direction of more information on this? Curious to learn more but my searches didn't turn up anything related.
- krenzo 7y ago
  I think they're referring to this: https://en.wikipedia.org/wiki/Somatotype_and_constitutional_psychology https://en.wikipedia.org/wiki/Somatotype_and_constitutional_...
stcredzero 7y ago
I remember when this idea came around Hacker News the last time. I mentioned this over lunch, and one of my (highly respected and deservedly considered intelligent) younger coworkers called BS on it. His object was: "Why would a government build an expensive, high tech piece of equipment, then not ensure it could fit the operator?" He just couldn't imagine it. Between 2020 and WWII, there is a huge difference in available technology and scale. There were a lot more planes and a lot more pilots back then. It's practically a WWII trope: Arguably "inferior" weapons systems win out because they can be produced in larger numbers with better maintainability and support logistics. (1) Depending on how you evaluate it, the amount of firepower and capability embodied in one WWII fighter is greatly dwarfed by that in one gen 4 or gen 5 fighter jet. (1) (Though, in WWII, Allied planes often had a tremendous advantage in performance, largely because they had access to far better fuel. This allowed for much higher compression ratios and higher pressure superchargers, so they could produce more power, more efficiently, for less weight. "Greg's Airplanes and Automobiles" on YouTube covers this.)
- Aloha 7y ago
  Our technology also continued to evolve throughout the war, updated fighters, better engines, even whole new designs. The Germans as far as mass produced designs went were effectively frozen in 1939. A lot of this was the complete inefficiency of the Reich Air Ministry at project management, as well as the political supremacy of the Heer over the Luftwaffe. In addition to the political whims of a dictatorship (Technological choices were often driven by ideology, and perception, much more than in the other dictatorship at the time (the Soviet Union, where for the most part, the technocrat reigned supreme)) All this said, from purely a material point of view the war in europe was won by the allies in 1941 when the US joined the conflict, but the Axis could have dragged the conflict out much longer had they had an effective strategic bombing program, and more modern fighters.
  - stcredzero 7y ago
    Our technology also continued to evolve throughout the war, updated fighters, better engines, even whole new designs. The Germans as far as mass produced designs went were effectively frozen in 1939. Well, not completely. "Greg's Airplanes and Automobiles" has a nice video on, "Why was the BF109K faster than the P51D? MW 50!" So to try and compensate for only having lower octane fuel, German engineers in WWII went to water/methanol injection for emergency power. Things did go back and forth quite a bit. Granted, the BF109 was one of the most advanced late 1930's designs going up against 1940's allied wartime designs. But there were times when updates on older designs would outclass the other sides slightly older versions, and this happened repeatedly on both sides. Technological choices were often driven by ideology, and perception, much more than in the other dictatorship at the time "Yes, but can it dive bomb?" probably did about as much to compromise designs of Nazi fighter/interceptors and slow the release of new airplanes as espionage and sabotage by the allies!
MaxBarraclough 7y ago
Anyone else seeing Firefox blocked a fingerprinter? Outline link: https://outline.com/uqNUEe https://outline.com/uqNUEe
MyHypatia 7y ago
Consider this set of statistics: 90% of elementary school teachers are female [1]. 90% of veterans are male [2]. Unsurprising. But, there are 2 million female veterans in the US, and only 1.7 million female elementary school teachers. That means if you talk to a random American female, it is more likely that she is a veteran than an elementary school teacher. I think a lot of disagreements on Hacker News and elsewhere stem from people saying "Well 90% of the time, X is true" without realizing that the 10% they are choosing to ignore is comprised of millions of people. [1] https://nces.ed.gov/programs/coe/indicator_clr.asp https://nces.ed.gov/programs/coe/indicator_clr.asp [2] https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.va.gov/vetdata/docs/SpecialReports/Women_Veterans_2015_Final.pdf&ved=2ahUKEwjmkMashv_oAhURrp4KHaUHDwIQFjABegQIDRAG&usg=AOvVaw1HeRlMh4mSIEx0AaXjN_G7 https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...
- abrahamneben 7y ago
  Enter bayes theorem
  - sudosysgen 7y ago
    Bayes' Theorem should be getting taught with quite some emphasis in high school, imo.
    - larrydag 7y ago
      I would argue that Bayes Theorem is taught in high school basically conditional probabilities and inferences. The issue is that applied Bayes Theorem is not taught. What do you do with information given with the data at hand?
      - TeMPOraL 7y ago
        Bayesian updates should be taught in schools, at least at the most coarse-grained level. Not to let people calculate anything; almost nobody is going to need that in life anyway. But so that some authority (which a school is) tells people they're allowed and supposed to update their beliefs on evidence. That evidence drags belief more in one direction than the other. That 0 and 1 are not probabilities in real life. That being certain of something is a rare thing, that they should embrace being more or less sure. That this is not someone's random worldview, but there is a proper (and rather fundamental) mathematical formalism behind it, it's just impossible to apply it fully in real life, so we have to approximate it.
cpascal 7y ago
This reminds me of a Planet Money podcast where they try to figure out the characteristics of the most typical American, or as they put it "who is the person I'm most likely to run into?" To construct this archetype, they used the mode of various dimensions rather than the median or average. https://www.npr.org/2019/08/28/755191639/episode-936-the-modal-american https://www.npr.org/2019/08/28/755191639/episode-936-the-mod...
lucas_membrane 7y ago
The referenced study of human dimensions was not the only thing done by the military to improve aviation safety. The discovery of human factors in user interfaces was also recognized. There had been some standardization of the cockpit controls of different aircraft during WWII and before, but not so much for the instruments and displays. That was no easy task, but the problem was recognized and addressed.
Symmetry 7y ago
Huh, the conventional story is that the UN forces won the air war in Korea because of better plane ergonomics despite Migs having better theoretical performance. But this report didn't come out until the war was mostly over. The conventional story emphasizes things like bubble canopies but still.
- redis_mlc 7y ago
  > the UN forces won the air war in Korea because of better plane ergonomics Well, the MiG-15 could outclimb our jets, but we got one and let Chuck Yeager test it. After that, more equal. Also, better visibility, comfort and I believe g-suits.
artsyca 7y ago
How many software engineers fit the mold of the bearded male craft beer connoisseur vs how many are trying to shoehorn themselves into it?
- artsyca 7y ago
  Not to pick on a single stereotype but it seems we've become memes and it's led to an attack of the clones on the ideas of diversity and inclusion flipping everything on its head Think about how 'fitting in' is also a term for 'averaging out' and ask yourself how much we value mediocrity? You can only join our group if you fit within one of these narrow guidelines and wear one size fits all clothing For crying out loud I'm sick of all the fakeness in the name of technology
  - themodelplumber 7y ago
    There's something more impersonal and less about authenticity, when you look at the factors involved in joining a group and becoming part of its identity, that's for sure. For that same reason though, I'm not sure I'd say that other groups differ so much. "Fake" realtors, "the typical hiker," or whatever it may be. The in-groups can often tell you about it first. Groups do seek their own identity over time, and sometimes groups can have identity crises, in which they arrive at a consensus on a new set of values after some other set of values has run its course. Even more importantly, individuals encountering this perspective--before the group does--have the opportunity to run early experiments and find new ways of being or communicating from the heart that may also be attractive to the social organism (of tech, or whatever). Someone with your outlook may be able to help with this...and that could really add up to a lot.
    - artsyca 7y ago
      Wow that's a very kind way of putting it I appreciate the warmth of your sentiment @themodelplumber
mauvehaus 7y ago
Human Dimension and Interior Space [0] is an interesting book if you're into this sort of thing. I mean, it's actually mostly not. It contains a vast number of tables covering percentiles for various human dimensions broken down by sex and age group. It does, however, also contain diagrams showing what measurements are relevant to certain activities. Chairs for instance, are covered for eating, office work, and lounging. Fun fact, the seat height of a chair is properly called "popliteal height". I end up pulling it out to answer such questions as: "Can I make the apron on this table go any lower assuming chairs in a normal-ish range of popliteal heights while preserving enough thigh clearance." [0] https://www.amazon.com/Human-Dimension-Interior-Space-Reference/dp/0823072711 https://www.amazon.com/Human-Dimension-Interior-Space-Refere...
WalterBright 7y ago
The military is one of the few governmental organizations where reality is ruthless enough that they are forced to adapt to it, rather than distorting reality to fit their agenda.
KyleBrandt 7y ago
Past convos https://news.ycombinator.com/item?id=11230287 https://news.ycombinator.com/item?id=11230287
zwaps 7y ago
By the way, this is also the reason why things like UI design have gotten so bad: Most Machine Learning algorithms fit averages. Combine them, and you learn surprisingly little!
deleted 7y ago
[deleted]
audiometry 7y ago
They make the leap to "better-fitting cockpits solved the problem of air crashes" without really proving it. I understand their theory, and it sounds believable. But it might be a spurious correlation.

273 points by elorant 7y ago

> any system designed around the average person is doomed to fail. Daniels published his findings in a 1952 Air Force Technical Note entitled The “Average Man”?

barbegal 7y ago
Which you can read here https://apps.dtic.mil/dtic/tr/fulltext/u2/010203.pdf https://apps.dtic.mil/dtic/tr/fulltext/u2/010203.pdf

war1025 7y ago

Thought this sounded familiar then realized it's a book review for a book I read a few years back. It was an interesting book. Recommend it to anyone who finds the article interesting.

duxup 7y ago

I wonder if this applies to something like performance reviews where measuring overall performance as something relative to 'average' inevitably doesn't make sense to anyone as perhaps there is no average there for a job with any level of complexity.

JoeAltmaier 7y ago

Been noted here on HN: the average web form excludes lots of people. Lots of folks cant fill in: First/middle/last name; unique username/password; social security number; street address; bank account. And not just folks in Micronesia or whatever. Heck my business partner hasn't got a deliverable street address - no mailbox at his house. He has a PO box. Is a nightmare getting Amazon deliveries that aren't lost, or left in the bushes, or returned undeliverable. Anyway, yes, there is no average person.

astrea 7y ago
The name field situation has never bothered me as a typical American with the standard name format, but as I've grown and met people from different cultures I've learned just how frustrating that part of forms can be. Even (or rather, especially?) government forms are terrible about this.
- NickM 7y ago
  Even typical Americans struggle with this sometimes if they have, say, hyphenated last names. I've encountered plenty of software out there that will reject or fail on even such a common case as this.
jbay 7y ago
There's so many times that an ostensibly international website has rejected me because I don't have a US-formatted numerical zip code. Even when they have a country field.

lalaithion 7y ago

Note that this is not some sort of unexpected effect due to humans not behaving mathematically ideally; this is what happens when your intuitions about 1, 2 and 3 dimensions are applied to higher dimensional spaces. Consider the goal of being in the middle 50% of a random value on one dimension; you have a 50% chance. But if you have two dimensions, and you want to be in the middle 50% for both of them, it's a 25% chance. And if you have 3, it's a ~12% chance. This already is counterintuitive, but when you ramp it up to 10 dimensions, it's a ~0.01% chance. That means that if you have a thousand people, only one of them (on average) will be in the middle 50% of all of them. Even the praised end state of the air force, with 9 dimensions and a required support of 90% of individuals of each dimension, implies that only 38% of individuals will be supported overall. (Granted, human dimensions aren't wholly uncorrelated.)

stygiansonic 7y ago
Great explanation. This is an example of the curse of dimensionality. An intuitive way to think about this is that each dimension you add is another “chance” for one of them to fall outside of the range. Another way to think about it is the often-cited unit n-dimensional sphere. If you were to uniformly sample points from within this n-dimensional sphere, as n increased, the proportion of points lying near the surface of the sphere would increase.
- Balgair 7y ago
  Numberphile has a good one on how these things can get crazy quickly: https://www.youtube.com/watch?v=mceaM2_zQd8 https://www.youtube.com/watch?v=mceaM2_zQd8
6gvONxR4sf7o 7y ago
I find it more intuitive to to discard the spatial intuition and think in terms of events. You want something in the X% norm? Think about it like a X%-heads biased coin flip. If you flip it enough times, it'd be shocking to get all heads. Even if the coin flips (dimensions) are correlated, many coin flips (dimensions) means at least some tails (dimension outside the norm).
7y ago

leephillips 7y ago

This is a really interesting article. The most fascinating part is to learn that the AF actually listened to the man and changed their policies. This kind of thing can happen even when only measuring a single dimension, if the distribution is multimodal. If everyone is either really short or really tall, then nobody will be near the average height.

macintux 7y ago
I realize that the audience is quite different, but it’s interesting to compare the response to “no woman matches our expectations” (means they’re fundamentally broken) vs “no man matches our expectations” (means the model is fundamentally broken).

RcouF1uZ4gsC 7y ago

> Out of 4,063 pilots, not a single airman fit within the average range on all 10 dimensions. > Less than 40 of the 3,864 contestants were average size on just five of the nine dimensions and none of the contestants — not even Martha Skidmore — came close on all nine dimensions. This seems more an issue of the "curse of dimensionality"[0] more than the "flaw of averages". Be very wary when you are trying to draw conclusions from a dataset with many dimensions. 0. https://en.wikipedia.org/wiki/Curse_of_dimensionality https://en.wikipedia.org/wiki/Curse_of_dimensionality

ken 7y ago
I don’t think so. They also said: > Even more astonishing, Daniels discovered that if you picked out just three of the ten dimensions of size ... less than 3.5 per cent of pilots would be average sized on all three dimensions.
- Someone 7y ago
  FTA: ”These formed the dimensions of the “average pilot,” which Daniels generously defined as someone whose measurements were within the middle 30 per cent of the range of values for each dimension.“ 0.3³ = 0.0027 = 2.7%, so if those measurements are independent of each other, it isn’t surprising that he found “less than 3.5 percent”.
  - Retric 7y ago
    I think the general assumption is arm length and height for example are strongly correlated.
  - Worker32850 7y ago
    Human dimensions are closer to a normal distribution. (Not quite normal, but let's pretend.) In that distribution then 46% of subjects should be in the middle 30% of 3 dimensions. [0] [0] With 4000 subjects they presumably have all sizes within ~3.5 stddevs represented. The middle ~1.2 stddevs should hold ~77% of the population. 0.77^3 = ~46%

clircle 7y ago

Even with just one dimension, the average may not be characteristic of the population.

tinalumfoil 7y ago

This interesting but all a bit wordy and meandering. Tldr: The air force was using the average dimensions of their pilots to design aircraft. Coincident to this, there was a large number of downed planes questionably attributed to "pilot error" but that many believed to be from an unknown cause. A recruit from Harvard charged with collecting data on pilots realized few people were close to the average, and recommending cockpits be fit to each individual. The AF took the recommendation and eventually companies produced aircraft with adjustable seating and cockpits. Tldr tldr: dont just reach for the average

jimhefferon 7y ago
> meandering I know. Isn't that wonderful?

AdrianB1 7y ago

This is a duplicate, see https://news.ycombinator.com/item?id=11230287 https://news.ycombinator.com/item?id=11230287, https://news.ycombinator.com/item?id=16220499 https://news.ycombinator.com/item?id=16220499 and more.

CalChris 7y ago

This reminds me of an old math joke. A statistician and a mathematician went duck hunting. From a blind, the mathematician shot and hit a duck. Their retriever went and got the duck. Then the statistician spotted and shot at another duck but shot too high. Quickly the statistician shot again but too low. The statistician then beamed with pride, on average, that's a dead duck.

ethbro 7y ago

The USAF employs averages in all kinds of interesting ways! "How US nuclear force modernization is undermining strategic stability: The burst-height compensating super-fuze" (or: How I Learned to Stop Worrying About Undershoot and Love Terminal Detonation Timing) https://news.ycombinator.com/item?id=16642280 https://news.ycombinator.com/item?id=16642280 (2018)

def8cefe 7y ago

>The Aero Medical Laboratory hired Daniels because he had majored in physical anthropology, a field that specialized in the anatomy of humans, as an undergraduate at Harvard. During the first half of the 20th century, this field focused heavily on trying to classify the personalities of groups of people according to their average body shapes — a practice known as “typing.” For example, many physical anthropologists believed a short and heavy body was indicative of a merry and fun-loving personality, while receding hairlines and fleshy lips reflected a “criminal type.” Can anyone point me in the direction of more information on this? Curious to learn more but my searches didn't turn up anything related.

krenzo 7y ago
I think they're referring to this: https://en.wikipedia.org/wiki/Somatotype_and_constitutional_psychology https://en.wikipedia.org/wiki/Somatotype_and_constitutional_...

stcredzero 7y ago

I remember when this idea came around Hacker News the last time. I mentioned this over lunch, and one of my (highly respected and deservedly considered intelligent) younger coworkers called BS on it. His object was: "Why would a government build an expensive, high tech piece of equipment, then not ensure it could fit the operator?" He just couldn't imagine it. Between 2020 and WWII, there is a huge difference in available technology and scale. There were a lot more planes and a lot more pilots back then. It's practically a WWII trope: Arguably "inferior" weapons systems win out because they can be produced in larger numbers with better maintainability and support logistics. (1) Depending on how you evaluate it, the amount of firepower and capability embodied in one WWII fighter is greatly dwarfed by that in one gen 4 or gen 5 fighter jet. (1) (Though, in WWII, Allied planes often had a tremendous advantage in performance, largely because they had access to far better fuel. This allowed for much higher compression ratios and higher pressure superchargers, so they could produce more power, more efficiently, for less weight. "Greg's Airplanes and Automobiles" on YouTube covers this.)

Aloha 7y ago
Our technology also continued to evolve throughout the war, updated fighters, better engines, even whole new designs. The Germans as far as mass produced designs went were effectively frozen in 1939. A lot of this was the complete inefficiency of the Reich Air Ministry at project management, as well as the political supremacy of the Heer over the Luftwaffe. In addition to the political whims of a dictatorship (Technological choices were often driven by ideology, and perception, much more than in the other dictatorship at the time (the Soviet Union, where for the most part, the technocrat reigned supreme)) All this said, from purely a material point of view the war in europe was won by the allies in 1941 when the US joined the conflict, but the Axis could have dragged the conflict out much longer had they had an effective strategic bombing program, and more modern fighters.
- stcredzero 7y ago
  Our technology also continued to evolve throughout the war, updated fighters, better engines, even whole new designs. The Germans as far as mass produced designs went were effectively frozen in 1939. Well, not completely. "Greg's Airplanes and Automobiles" has a nice video on, "Why was the BF109K faster than the P51D? MW 50!" So to try and compensate for only having lower octane fuel, German engineers in WWII went to water/methanol injection for emergency power. Things did go back and forth quite a bit. Granted, the BF109 was one of the most advanced late 1930's designs going up against 1940's allied wartime designs. But there were times when updates on older designs would outclass the other sides slightly older versions, and this happened repeatedly on both sides. Technological choices were often driven by ideology, and perception, much more than in the other dictatorship at the time "Yes, but can it dive bomb?" probably did about as much to compromise designs of Nazi fighter/interceptors and slow the release of new airplanes as espionage and sabotage by the allies!

MaxBarraclough 7y ago

Anyone else seeing Firefox blocked a fingerprinter? Outline link: https://outline.com/uqNUEe https://outline.com/uqNUEe

MyHypatia 7y ago

Consider this set of statistics: 90% of elementary school teachers are female [1]. 90% of veterans are male [2]. Unsurprising. But, there are 2 million female veterans in the US, and only 1.7 million female elementary school teachers. That means if you talk to a random American female, it is more likely that she is a veteran than an elementary school teacher. I think a lot of disagreements on Hacker News and elsewhere stem from people saying "Well 90% of the time, X is true" without realizing that the 10% they are choosing to ignore is comprised of millions of people. [1] https://nces.ed.gov/programs/coe/indicator_clr.asp https://nces.ed.gov/programs/coe/indicator_clr.asp [2] https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.va.gov/vetdata/docs/SpecialReports/Women_Veterans_2015_Final.pdf&ved=2ahUKEwjmkMashv_oAhURrp4KHaUHDwIQFjABegQIDRAG&usg=AOvVaw1HeRlMh4mSIEx0AaXjN_G7 https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...

abrahamneben 7y ago
Enter bayes theorem
- sudosysgen 7y ago
  Bayes' Theorem should be getting taught with quite some emphasis in high school, imo.
  - larrydag 7y ago
    I would argue that Bayes Theorem is taught in high school basically conditional probabilities and inferences. The issue is that applied Bayes Theorem is not taught. What do you do with information given with the data at hand?
    - TeMPOraL 7y ago
      Bayesian updates should be taught in schools, at least at the most coarse-grained level. Not to let people calculate anything; almost nobody is going to need that in life anyway. But so that some authority (which a school is) tells people they're allowed and supposed to update their beliefs on evidence. That evidence drags belief more in one direction than the other. That 0 and 1 are not probabilities in real life. That being certain of something is a rare thing, that they should embrace being more or less sure. That this is not someone's random worldview, but there is a proper (and rather fundamental) mathematical formalism behind it, it's just impossible to apply it fully in real life, so we have to approximate it.

cpascal 7y ago

This reminds me of a Planet Money podcast where they try to figure out the characteristics of the most typical American, or as they put it "who is the person I'm most likely to run into?" To construct this archetype, they used the mode of various dimensions rather than the median or average. https://www.npr.org/2019/08/28/755191639/episode-936-the-modal-american https://www.npr.org/2019/08/28/755191639/episode-936-the-mod...

lucas_membrane 7y ago

The referenced study of human dimensions was not the only thing done by the military to improve aviation safety. The discovery of human factors in user interfaces was also recognized. There had been some standardization of the cockpit controls of different aircraft during WWII and before, but not so much for the instruments and displays. That was no easy task, but the problem was recognized and addressed.

Symmetry 7y ago

Huh, the conventional story is that the UN forces won the air war in Korea because of better plane ergonomics despite Migs having better theoretical performance. But this report didn't come out until the war was mostly over. The conventional story emphasizes things like bubble canopies but still.

redis_mlc 7y ago
> the UN forces won the air war in Korea because of better plane ergonomics Well, the MiG-15 could outclimb our jets, but we got one and let Chuck Yeager test it. After that, more equal. Also, better visibility, comfort and I believe g-suits.

artsyca 7y ago

How many software engineers fit the mold of the bearded male craft beer connoisseur vs how many are trying to shoehorn themselves into it?

artsyca 7y ago
Not to pick on a single stereotype but it seems we've become memes and it's led to an attack of the clones on the ideas of diversity and inclusion flipping everything on its head Think about how 'fitting in' is also a term for 'averaging out' and ask yourself how much we value mediocrity? You can only join our group if you fit within one of these narrow guidelines and wear one size fits all clothing For crying out loud I'm sick of all the fakeness in the name of technology
- themodelplumber 7y ago
  There's something more impersonal and less about authenticity, when you look at the factors involved in joining a group and becoming part of its identity, that's for sure. For that same reason though, I'm not sure I'd say that other groups differ so much. "Fake" realtors, "the typical hiker," or whatever it may be. The in-groups can often tell you about it first. Groups do seek their own identity over time, and sometimes groups can have identity crises, in which they arrive at a consensus on a new set of values after some other set of values has run its course. Even more importantly, individuals encountering this perspective--before the group does--have the opportunity to run early experiments and find new ways of being or communicating from the heart that may also be attractive to the social organism (of tech, or whatever). Someone with your outlook may be able to help with this...and that could really add up to a lot.
  - artsyca 7y ago
    Wow that's a very kind way of putting it I appreciate the warmth of your sentiment @themodelplumber

mauvehaus 7y ago

Human Dimension and Interior Space [0] is an interesting book if you're into this sort of thing. I mean, it's actually mostly not. It contains a vast number of tables covering percentiles for various human dimensions broken down by sex and age group. It does, however, also contain diagrams showing what measurements are relevant to certain activities. Chairs for instance, are covered for eating, office work, and lounging. Fun fact, the seat height of a chair is properly called "popliteal height". I end up pulling it out to answer such questions as: "Can I make the apron on this table go any lower assuming chairs in a normal-ish range of popliteal heights while preserving enough thigh clearance." [0] https://www.amazon.com/Human-Dimension-Interior-Space-Reference/dp/0823072711 https://www.amazon.com/Human-Dimension-Interior-Space-Refere...

WalterBright 7y ago

The military is one of the few governmental organizations where reality is ruthless enough that they are forced to adapt to it, rather than distorting reality to fit their agenda.

KyleBrandt 7y ago

Past convos https://news.ycombinator.com/item?id=11230287 https://news.ycombinator.com/item?id=11230287

zwaps 7y ago

By the way, this is also the reason why things like UI design have gotten so bad: Most Machine Learning algorithms fit averages. Combine them, and you learn surprisingly little!

deleted 7y ago

[deleted]

audiometry 7y ago

They make the leap to "better-fitting cockpits solved the problem of air crashes" without really proving it. I understand their theory, and it sounds believable. But it might be a spurious correlation.