3 ms·

> 35% of a million requests is different than 35% of a billion. Not statistically.

alwa 2y ago
A mentor I respect memorably explained to young me that “it doesn’t matter how big the pot of soup, you can use the same size spoon to taste it.”
- beefnugs 2y ago
  Sorry but that mentor has a small practical imagination, a pot can be so large that the top 3 feet that you reach with that spoon could be all oil
  - alwa 2y ago
    True! Consistency and representativeness matter, in soup samples as in social samples! Is the soup smooth or lumpy? Striated or uniform? For that matter a soup could (and often does) involve huge soup bones that give it important parts of its flavor, but never show up directly in a spoonful. And you might need something different from a spoon to convincingly rule out some specific rare lumpy ingredient. The didactic value of sampling the soup pot goes well behind its basic function: correcting the beginner’s misperception that a sample’s statistical power is directly related to population size :)
  - skeeter2020 2y ago
    to push this analogy too far, that's because you didn't stir it well, not because the spoon is too small.
    - prepend 2y ago
      Have to sample to see if it’s stirred well enough.
      - brookst 2y ago
        No, you can model whether stirring actions should create a representative sample
        Terretta 2y ago
        Not with immiscible layered stratified flow… “You're gonna need a bigger spoon!”
layman51 2y ago
What do you mean by “statistically”? The end results would be like three orders of magnitude apart. Wouldn’t the desired sample size depend on the size of the population itself?
- famouswaffles 2y ago
  >Wouldn’t the desired sample size depend on the size of the population itself? No, The most important thing is the distribution of the sample size. You have to make sure it isn't obviously biased in some way (i.e You're only surveying students in a university for extrapolation on the entire population of the country). Beyond that, the desired sample size levels off quickly. 5000 (assuming the same distribution) won't be any more or less accurate for 10M than it is for 1M. Of course, if you just ask everyone or almost everyone then you no longer need to worry about distribution but yeah
olddustytrail 2y ago
Yes statistically. What do you think "statistically" means?
ggm 2y ago
35% of a million students in the USA is very different to 35% of a billion students across the USA, Europe and Africa. Since there aren't a billion students in the USA, 35% of them is an impossibility. If you scale your population above some recognized boundary you aren't sampling in the same space any more. After all the local star density to 1AU tends very strongly to 1. That's not indicative of the actual star density in the milky way.

alwa 2y ago

A mentor I respect memorably explained to young me that “it doesn’t matter how big the pot of soup, you can use the same size spoon to taste it.”

beefnugs 2y ago
Sorry but that mentor has a small practical imagination, a pot can be so large that the top 3 feet that you reach with that spoon could be all oil
- alwa 2y ago
  True! Consistency and representativeness matter, in soup samples as in social samples! Is the soup smooth or lumpy? Striated or uniform? For that matter a soup could (and often does) involve huge soup bones that give it important parts of its flavor, but never show up directly in a spoonful. And you might need something different from a spoon to convincingly rule out some specific rare lumpy ingredient. The didactic value of sampling the soup pot goes well behind its basic function: correcting the beginner’s misperception that a sample’s statistical power is directly related to population size :)
- skeeter2020 2y ago
  to push this analogy too far, that's because you didn't stir it well, not because the spoon is too small.
  - prepend 2y ago
    Have to sample to see if it’s stirred well enough.
    - brookst 2y ago
      No, you can model whether stirring actions should create a representative sample
      - Terretta 2y ago
        Not with immiscible layered stratified flow… “You're gonna need a bigger spoon!”

layman51 2y ago

What do you mean by “statistically”? The end results would be like three orders of magnitude apart. Wouldn’t the desired sample size depend on the size of the population itself?

famouswaffles 2y ago
>Wouldn’t the desired sample size depend on the size of the population itself? No, The most important thing is the distribution of the sample size. You have to make sure it isn't obviously biased in some way (i.e You're only surveying students in a university for extrapolation on the entire population of the country). Beyond that, the desired sample size levels off quickly. 5000 (assuming the same distribution) won't be any more or less accurate for 10M than it is for 1M. Of course, if you just ask everyone or almost everyone then you no longer need to worry about distribution but yeah

olddustytrail 2y ago

Yes statistically. What do you think "statistically" means?

ggm 2y ago

35% of a million students in the USA is very different to 35% of a billion students across the USA, Europe and Africa. Since there aren't a billion students in the USA, 35% of them is an impossibility. If you scale your population above some recognized boundary you aren't sampling in the same space any more. After all the local star density to 1AU tends very strongly to 1. That's not indicative of the actual star density in the milky way.