The Fool wrote:
> A second counter-intuitive aspect of power laws is that most elements in
> a power law system are below average, because the curve is so heavily
> weighted towards the top performers. In Figure #1, the average number of
> inbound links (cumulative links divided by the number of blogs) is 31.
> The first blog below 31 links is 142nd on the list, meaning two-thirds of
> the listed blogs have a below average number of inbound links. We are so
> used to the evenness of the bell curve, where the median position has the
> average value, that the idea of two-thirds of a population being below
> average sounds strange. (The actual median, 217th of 433, has only 15
> inbound links.)
The bell curve is an example where the mean, the median and the mode are all
the same.
In a great many distributions, however, this is not the case.
Take, for example, number of arms per person.
The mean is going to be less than 2, because some people are lacking 1 or 2
arms, being left with 0 or 1. But the mode is going to be 2, because almost
everyone has 2 arms. And if you lined up everyone according to the number
of arms they have, and took the person in the middle, he'd have 2 arms, so
the median is 2.
Julia
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