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   gav (gav@cawfee.club)'s status on Wednesday, 05-Nov-2025 10:43:32 JST gav
   https://www.youtube.com/watch?v=33y9FMIvcWY
   
   Why Wikipedia Can't Explain Math
   
   14:11
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     Rusty Crab (rustycrab@clubcyberia.co)'s status on Wednesday, 05-Nov-2025 10:43:31 JST Rusty Crab

     in reply to
     @gav I was complaining about exactly this the other day. Same problem that all Wikipedia editors have: their head is so far up their ass they've discovered several new kinds of polyps
     Forest of Enchantment likes this.
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     gav (gav@cawfee.club)'s status on Wednesday, 05-Nov-2025 10:43:32 JST gav

     in reply to
     incessant coping about it being and encyclopedia in the comments
     
     cant even frankenstein a functional definition out of several pages when it should be on the top of the relevant page
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     mist (ai@cawfee.club)'s status on Thursday, 06-Nov-2025 07:52:47 JST mist

     in reply to

     • lait accompli
     • mist
     • karna :flipflop: :buffsuki:
     @gav @genmaicha @karna btw gav you should read wikipedia like this:
     
     1. scroll past the intro section and look for a definition section
     2. if there is something that syntactically looks like a math definition (reasonably short, symbols are defined and then used in some statement), then read it
     3. if there is no definition section or the """definition""" is not actually a definition, then curse the Marxist Left and move on
     
     this has made my life better
     :ihavenomouth: likes this.
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     mist (ai@cawfee.club)'s status on Thursday, 06-Nov-2025 07:52:48 JST mist

     in reply to

     • lait accompli
     • karna :flipflop: :buffsuki:
     @gav @karna @genmaicha Once again gav is an untutored math genius and I agree with him
     
     "a variance is the mean of [SQUARED] differences of a set of numbers from their mean" is fine. An expert will understand that 'mean' is defined as an expectation and usually calculated as an integral, 'set' should specify the probability measure, etc. Covariance is just when the data is higher-dimensional, so the 'squared differences' must also live in a higher-dimensional space.
     
     I have not heard of "mean" implying "finite state space" even to the layperson. Most high school calc classes ask students to calculate "averages" or "means" with integrals
     
     Objection: "but the encyclopedia is trying to give the most general definition, useful to professionals, not just one special case known a century ago"
     
     Is there a general definition, though, which is not essentially that? Specifying the method of calculation (taking integrals) or interpretation or purpose or generalizations (covariance) does not belong in a formal definition.
     
     BTW, this is the main problem with the excessively long """definition""" of the page https://en.wikipedia.org/wiki/Coefficient_of_determination#Definitions , where the authors lump in interpretations and relationships with other concepts. These things do not belong in a (ideally, short) definition.
     
     Objection: "but there are multiple definitions of R2, and this causes issues in stats literature!"
     
     The multiple definitions have to do with how the phrase "variance of the data" is defined (e.g. centered or uncentered, that is, whether you subtract off the mean). This is not addressed in the article at all
     
     The problem with the spinor article https://en.wikipedia.org/wiki/Spinor is that it is trying too hard to be accessible to *nonexperts*, and ends up being too wordy for experts and too vague for the layperson. How many paragraphs does it take to get to "a spinor is a representation of the spin group [or, if you like, some clifford algebra]"? Someone who can't understand these words or look them up will not understand the article anyways. And if you lead with a clear definition, at least the layperson knows what to look up (I think this is gav's point).
     
     If you dig around in wikipedia talk pages, you see that even terms like "unit vector" and "SO(3)" are deleted from articles in an effort to get them approved as 'featured articles.' The idea is that to be a featured article, it must be accessible to a broad audience. But replacing jargon with vague circumlocutions just makes things worse for the layperson *and* the expert. This is the shittiest thing about science wikipedia
     
     The articles which are truly written "primarily for professionals" as you (karna) are saying, I feel are actually great and have none of the issues that gav is complaining about. I just wish that was more of them. Often these articles are more niche, rated "low-importance", and are thus unmolested by wikipedia super-editors and their WIKI: policies
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     karna :flipflop: :buffsuki: (karna@poa.st)'s status on Thursday, 06-Nov-2025 07:52:49 JST karna :flipflop: :buffsuki:

     in reply to

     • lait accompli
     @gav @genmaicha I wasnt defending it, just describing the reality of it. But I'll play devils advocate now :HazeSmug: :
     
     
     >In statistics, the coefficient of determination, denoted R2 or r2 and pronounced "R squared", is the proportion of the variation in the dependent variable that is predictable from the independent variable(s).
     The first sentence is not a definition but something to guide one's (read a mathematician's) intuition
     
     > statistic used in the context of statistical models...
     
     "statistic" is jargon with a very specific meaning and while it sounds funny in this sentence, it is still worth mentioning since it helps with understanding what role in statistics this quantity has, namely, exactly what is spelled out in the next half of this sentence.
     
     > they exclusively define the ourcome and minutia but never define the actual operation
     
     there is literally a "definition" section which spells out how to calculate it for a dataset with the steps for the mean, residual sum of squares, total sum of squares, and finally the formula. Thats a pretty clear algorithm in my books. Arguably what's missing are some examples to further spell this out.
     
     For the variance stuff, the first sentence is pretty much an english language version of the formula definition of the variance.
     
     Theres also some impedance mismatches between what you and the authors want here. The first is related to:
     
     > the primary reason to go to a math wiki is what am i looking at, what is it derived from, what does it prove, how do i reproduce it
     
     Like I mentioned in my previous post this is orthogonal to what the authors care about. Their target audience is not a math noob but a grad student (or higher) and I wouldn't be surprised if the majority of the actual readers of such pages were undergrad/grad students. They dont want to write a textbook but a refresher for someone who is aware of at least some of underlying theory.
     
     The second mismatch is related to terminology and definitions. Most of the simple definitions at the end of your poast are not general enough for the mathematician. Take the variance case:
     
     > a variance is the mean of differences of a set of numbers from their mean
     >
     > you immediately understand generically what it derives from how to calculate it and what sort of things it could imply
     
     This only holds in the specific case when you are working with discrete probability spaces where the expectation value happens to be the same as taking a mean of some numbers. But the variance is defined for a larger category of things. If there is a continuous random variable being studied then its expectation value (and hence variance) will likely involve integrals (there are definitions of certain averages that use integrals so its not too out of left field). That is, the Wikipedia pages are trying to capture some of this abstraction and generality since the target audience is a mathematician and not a layman. Spelling it out more, to the the mathematician, your last point doesnt match the definition you gave for variance: it is not generic enough and as such does not capture the full scope of implications that would follow from the more general definition
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     gav (gav@cawfee.club)'s status on Thursday, 06-Nov-2025 07:52:49 JST gav

     in reply to

     • lait accompli
     • karna :flipflop: :buffsuki:
     @karna @genmaicha variance is a word with a meaning, every other definition is an abstraction of the one i gave, there are plenty of extentions from discrete to none discrete and from integers to non integers, discrete integers naturally capture its own extensions
     
     if it doesnt i really dont see how it could be described by the word
     
     
     definition sections are usually extraordinarily confusing
     
     genuinely like in the video you get confused about what you came in knowing
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     karna :flipflop: :buffsuki: (karna@poa.st)'s status on Thursday, 06-Nov-2025 07:52:50 JST karna :flipflop: :buffsuki:

     in reply to

     • lait accompli

     @genmaicha @gav 1 is mostly true, and in particular math wikipedia is mostly written by people with at least a graduate education in math for people with at least a graduate education in math so that they can brush up on stuff they often already know when needed, or to bootstrap the process of finding references to cite in their papers.

     t. theorycel

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     gav (gav@cawfee.club)'s status on Thursday, 06-Nov-2025 07:52:50 JST gav

     in reply to

     • lait accompli
     • karna :flipflop: :buffsuki:
     @karna @genmaicha >In statistics, the coefficient of determination, denoted R2 or r2 and pronounced "R squared", is the proportion of the variation in the dependent variable that is predictable from the independent variable(s). It is a statistic used in the context of statistical models
     
     they exclusively define the ourcome and minutia but never define the actual operation
     
     everytime i dont know something in math amd go to wikipedia this is what i run into
     
     >statistic used in the context of statistical models
     thanks bro
     
     >In probability theory and statistics, variance is the expected value of the squared deviation from the mean of a random variable. The standard deviation (SD) is obtained as the square root of the variance. Variance is a measure of dispersion, meaning it is a measure of how far a set of numbers are spread out from their average value. It is the second central moment of a distribution, and the covariance of the random variable with itself, and it is often represented by
     
     it then leads the definition section with calculating based on the expected value
     
     variance is when variance, not even circular but classicly circular
     
     
     the primary reason to go to a math wiki is what am i looking at, what is it derived from, what does it prove, how do i reproduce it
     
     none of these are completely shown even for rudimentary concepts
     
     a mean is a sum of numbers divided by how many of there are
     
     a variance is the mean of differences of a set of numbers from their mean
     
     you immediately understand generically what it derives from how to calculate it and what sort of things it could imply
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     gav (gav@cawfee.club)'s status on Thursday, 06-Nov-2025 07:52:52 JST gav

     in reply to

     • lait accompli
     @genmaicha its just bizzar that they cant lead with a useable definition
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     lait accompli (genmaicha@stereophonic.space)'s status on Thursday, 06-Nov-2025 07:52:52 JST lait accompli

     in reply to
     @gav this could be for a couple reasons; I'm thinking (1) because the people writing the articles are theorycels and don't actually care about applications; and (2) because there are too many applications to describe in a single article.
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     lait accompli (genmaicha@stereophonic.space)'s status on Thursday, 06-Nov-2025 07:52:54 JST lait accompli

     in reply to
     @gav yeah, wikipedia mostly just enumerates properties and theorems rather than explaining how to use things.