Re: As usual
That is a good point. What we can postulate is that the readership of El Reg is more technically orientated unless there are more masochists or lost carrion bird fanciers than we could assume would visit. This means that we expect a skew compared to the internet as a whole.
This means we have a smaller pool which targets specialists. So a reasonable assumption is that a smaller pool for one website will not be reflective of the netmarketshare pool, unless they are only operable on The Register.
Now, it would be possible to check the benchline of OS breakdown for the Reg and it normally wouldn't be unusual to see if there is a corrosponding drop in stats for 8.1 and rise for XP, but at the same time, XP is more likely *not* to be used amongst IT professionals apart from those locations where they are forced to in an enterprise situation and theregister isn't blocked.
So we have three assumptions here:
1. Netmarketshare is more generalised than The Register visitors.
2. The Register visitors are more likely to be in IT service businesses/departments
3. Netmarketshare doesn't just show results from the The Register.
Reasonable taken separately, but combined that then starts to increase liklihood of error.
Not remarkable a conclusion, maybe, though I thank you for making such a claim on my behalf - I don't often get such praise. But it certainly is a reasonable set of assumptions to make that any corroboration The Register visitors make is only ever going to be meaningless considering the size of the dip/rise in question, it would just be too small a comparison even if there were a similar spike/dip.
Then there is the possibility of a DOS attack from a botnet of compromised XP pcs on one particular site - that could produce an alteration in stats of that magnitude, theoretically.
Welcome to statistics.