4 ms·

Gates was right in "What've you got in there? Movies? PowerPoint presentations?" A variant of the 80/20 rule probably applies to email: 80% of the size of your

by jc123 15y ago

Gates was right in "What've you got in there? Movies? PowerPoint presentations?" A variant of the 80/20 rule probably applies to email: 80% of the size of your inbox is caused by the 20% largest emails.

Jabbles 15y ago
True, although it would be hard not to have such a rule: where something is shared among a sufficiently large set of participants, there must be a number k between 50 and 100 such that "k% is taken by (100 − k)% of the participants http://en.wikipedia.org/wiki/Pareto_principle http://en.wikipedia.org/wiki/Pareto_principle
- esrauch 15y ago
  Yeah, that is pretty obvious. No one would bother saying that 55% of the space is taken by 45% of the email though. It is mentioned because of high difference between the two values.
  - kragen 15y ago
    I think that would be worth pointing out, because it's such a huge deviation from the quasi-Zipfian behavior you'd expect.
- jamesbritt 15y ago
  There's no reason those numbers need to sum to 100. E.g. 90% of X could be contolled by 30% of the people using X.
  - Troll_Whisperer 15y ago
    If it's a continuous function, they need to sum at some point. A lot of real world things are close enough to continuous for all practical purposes, though I'll concede that we aren't actually sending and receiving email infinitesimals.
    - jamesbritt 15y ago
      My point is that you have two distinct variables or percentages. It's unfortunate that it gets called the "80/20 Rule" because people see that and think, Oh, the two numbers have to add to 100. It's not a rule. It's the idea that things are not always as balanced/equal/proportioned as one might hope or expect. For example, there's the claim that, in the USA, 25 percent of households own 87 percent of all U.S. wealth. It's an example of the Pareto Principle in the form of 87/25. 100 only plays a role insofar as nether value can exceed it (since the numbers refer to percentages).
      - kragen 15y ago
        There are an infinite number of such pairs of numbers. 87, 25 may be one of them; perhaps 83, 22 is another, and 88, 28 is another, all describing the same distribution. But of all of those pairs of numbers, there is exactly one pair that sums to 100. If you want to compare the inequality of two distributions of wealth (or whatever), that pair of numbers is a reasonable candidate metric: an 80, 20 distribution is more equal than a 90, 10 distribution, and more unequal than a 70, 30 distribution. The Gini coefficient is another scalar that can be used to rank distributions by inequality.
        jamesbritt 15y ago
        There are an infinite number of such pairs of numbers. 87, 25 may be one of them; perhaps 83, 22 is another, and 88, 28 is another, all describing the same distribution. But they don't, and that's a key point. The numbers are, in fact (in this example) 25% and 87%. Different numbers would describe a different situation. They are not percentages of the same thing; they are percentages of two different things.
        kragen 15y ago
        You are mistaken in your assertion that those sets of numbers necessarily describe different distributions or situations. I will explain this more carefully so that you can understand what the key points actually are. Please take the time to read and understand the explanation below. You are correct that they are percentages of two different things. However, if 87% of the wealth, whatever that is, belongs to the richest 25% of the population, then it's entirely possible for 88% of the wealth to simultaneously belong to the richest 28% of the population. That would just mean that 1% of the wealth belongs to the 3% of the population between the 72nd and 75th percentile, which is an entirely plausible state of affairs. Consider, for any number X from 0 to 100, you can find a number Y that makes the statement "The richest X% of the population owns Y% of the wealth" true, without changing the distribution. Y is continuous and increases monotonically with X; and when X=0, Y=0; and when X=100, Y=100. Under those conditions, there is guaranteed to be exactly one point in [0, 100] where X = 100-Y. If you want to compare two different distributions, it's helpful to oversimplify them to scalars, since otherwise you have vectors in an infinite-dimensional Hilbert space, which are tricky to compare. If you know that in the US, the richest 25% of the population controls 87% of the wealth, while in Argentina, the richest 10% of the population controls 70% of the wealth (it doesn't), you don't know which country is more unequal. It could be that the richest 10% of the population in the US controls 87% of the wealth, or 34.8% of the wealth, or anything in between. Furthermore, it could simultaneously be the case that, in the US, the richest 10% of the population controls 80% of the wealth (making the US seem more unequal), while in Argentina, the richest 25% of the population controls 90% of the wealth (making Argentina seem more unequal). There are lots of possible choices of scalar. The smallest percentage of the population that controls 50% of the wealth is one reasonable candidate. The percentage of the wealth controlled by the richest 50% of the population is another. The Gini coefficient is a third. And that unique point of intersection where the richest X% of the population controls (100-X)% of the wealth is a fourth. Does that clarify matters?
redthrowaway 15y ago
You could probably project that to 95/5 in the case of emails, where the expected case is miniscule and the worst case is huge. If you manage to go through a gig of inbox space in a couple months, there have to be some massive files there accounting for the bulk of your storage.
- mjschultz 15y ago
  I'm inclined to agree with this fraction. I just used POP3 to LIST the first 360 messages in my mailbox and the graph shows an distinct upshot around 95%. Around 95% of my (360) emails consume 6.5% of the space (360 messages take).

by jc123 15y ago

Jabbles 15y ago

True, although it would be hard not to have such a rule: where something is shared among a sufficiently large set of participants, there must be a number k between 50 and 100 such that "k% is taken by (100 − k)% of the participants http://en.wikipedia.org/wiki/Pareto_principle http://en.wikipedia.org/wiki/Pareto_principle

esrauch 15y ago
Yeah, that is pretty obvious. No one would bother saying that 55% of the space is taken by 45% of the email though. It is mentioned because of high difference between the two values.
- kragen 15y ago
  I think that would be worth pointing out, because it's such a huge deviation from the quasi-Zipfian behavior you'd expect.
jamesbritt 15y ago
There's no reason those numbers need to sum to 100. E.g. 90% of X could be contolled by 30% of the people using X.
- Troll_Whisperer 15y ago
  If it's a continuous function, they need to sum at some point. A lot of real world things are close enough to continuous for all practical purposes, though I'll concede that we aren't actually sending and receiving email infinitesimals.
  - jamesbritt 15y ago
    My point is that you have two distinct variables or percentages. It's unfortunate that it gets called the "80/20 Rule" because people see that and think, Oh, the two numbers have to add to 100. It's not a rule. It's the idea that things are not always as balanced/equal/proportioned as one might hope or expect. For example, there's the claim that, in the USA, 25 percent of households own 87 percent of all U.S. wealth. It's an example of the Pareto Principle in the form of 87/25. 100 only plays a role insofar as nether value can exceed it (since the numbers refer to percentages).
    - kragen 15y ago
      There are an infinite number of such pairs of numbers. 87, 25 may be one of them; perhaps 83, 22 is another, and 88, 28 is another, all describing the same distribution. But of all of those pairs of numbers, there is exactly one pair that sums to 100. If you want to compare the inequality of two distributions of wealth (or whatever), that pair of numbers is a reasonable candidate metric: an 80, 20 distribution is more equal than a 90, 10 distribution, and more unequal than a 70, 30 distribution. The Gini coefficient is another scalar that can be used to rank distributions by inequality.
      - jamesbritt 15y ago
        There are an infinite number of such pairs of numbers. 87, 25 may be one of them; perhaps 83, 22 is another, and 88, 28 is another, all describing the same distribution. But they don't, and that's a key point. The numbers are, in fact (in this example) 25% and 87%. Different numbers would describe a different situation. They are not percentages of the same thing; they are percentages of two different things.
        kragen 15y ago
        You are mistaken in your assertion that those sets of numbers necessarily describe different distributions or situations. I will explain this more carefully so that you can understand what the key points actually are. Please take the time to read and understand the explanation below. You are correct that they are percentages of two different things. However, if 87% of the wealth, whatever that is, belongs to the richest 25% of the population, then it's entirely possible for 88% of the wealth to simultaneously belong to the richest 28% of the population. That would just mean that 1% of the wealth belongs to the 3% of the population between the 72nd and 75th percentile, which is an entirely plausible state of affairs. Consider, for any number X from 0 to 100, you can find a number Y that makes the statement "The richest X% of the population owns Y% of the wealth" true, without changing the distribution. Y is continuous and increases monotonically with X; and when X=0, Y=0; and when X=100, Y=100. Under those conditions, there is guaranteed to be exactly one point in [0, 100] where X = 100-Y. If you want to compare two different distributions, it's helpful to oversimplify them to scalars, since otherwise you have vectors in an infinite-dimensional Hilbert space, which are tricky to compare. If you know that in the US, the richest 25% of the population controls 87% of the wealth, while in Argentina, the richest 10% of the population controls 70% of the wealth (it doesn't), you don't know which country is more unequal. It could be that the richest 10% of the population in the US controls 87% of the wealth, or 34.8% of the wealth, or anything in between. Furthermore, it could simultaneously be the case that, in the US, the richest 10% of the population controls 80% of the wealth (making the US seem more unequal), while in Argentina, the richest 25% of the population controls 90% of the wealth (making Argentina seem more unequal). There are lots of possible choices of scalar. The smallest percentage of the population that controls 50% of the wealth is one reasonable candidate. The percentage of the wealth controlled by the richest 50% of the population is another. The Gini coefficient is a third. And that unique point of intersection where the richest X% of the population controls (100-X)% of the wealth is a fourth. Does that clarify matters?

redthrowaway 15y ago

You could probably project that to 95/5 in the case of emails, where the expected case is miniscule and the worst case is huge. If you manage to go through a gig of inbox space in a couple months, there have to be some massive files there accounting for the bulk of your storage.

mjschultz 15y ago
I'm inclined to agree with this fraction. I just used POP3 to LIST the first 360 messages in my mailbox and the graph shows an distinct upshot around 95%. Around 95% of my (360) emails consume 6.5% of the space (360 messages take).