[whatwg] Issues concerning the <base> element and xml:base
Philip Taylor
excors+whatwg at gmail.com
Tue Aug 7 06:16:21 PDT 2007
On 07/08/07, Ian Hickson <ian at hixie.ch> wrote:
> This is how it stood back in May (using a sample of several hundred
> thousand pages taken mostly from the more popular sites); number of unique
> URIs in <base href> attributes as a percentage of all pages parsed:
>
> 0: 93.7%
> 1: 6.31%
> 2: 0.0308%
> 3: 0.00105%
> 4: 0.00197%
>
> This is how it stands as of today (using the same sampling method):
>
> 0: 94.1%
> 1: 5.93%
> 2: 0.0215%
> 3: 0.000928%
> 4: 0.000288%
>
> (All numbers rounded to three significant figures.)
That rounding seems quite misleading - if I haven't forgotten how to
do statistics, and if the details I am forgetting are not critical
ones, and if I'm not misinterpreting how you collected the data, then
the samples are independent and from a binomial distribution that can
be approximated as a normal distribution with standard deviation
sqrt(n*p*(1-p)), and if assuming n=100,000 and guessing p from the
data then the 95%-confidence (+/- 2 s.d.) ranges are something like:
0: (93.7 +/- 0.15)%
1: (6.3 +/- 0.15)%
2: (0.03 +/- 0.01)%
3: (0.001 +/- 0.002)%
4: (0.002 +/- 0.003)%
and
0: (94.1 +/- 0.15)%
1: (5.9 +/- 0.15)%
2: (0.02 +/- 0.01)%
3: (0.001 +/- 0.002)%
4: (0.0003 +/- 0.001)%
(though the normal approximation breaks down in the <= 0.002% bits),
so you can't determine anything about changes in frequency beyond the
zero/one cases.
--
Philip Taylor
excors at gmail.com
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