re: Bing gains, Google drops

James — Thu, 02 Jul 2009 13:37:27 GMT

I suspect that it's both better and worse than that.

If they're a tracking firm, they're probably not asking anyone directly. They would have tracking bugs on a large number of websites, and are probably looking at HTTP referer headings to see which search engines sent enquirers to their sites. They can probably also use cookies to identify individual users and tell which search engines they use. So they probably do have enough data to reasonably give that level of precision.

But it's not random sampling. There's no way to know that they don't have systemic accuracy issues.

One could quibble that their customers are not exactly randomly chosen, so what they see may not be representative. Also, one might expect that (say) Bing gives more information about links, so Bing users will visit fewer sites in response to a Bing query, and so StatCounter is less likely to see Bing users that don't use search engines very often.

On the other hand, these systemic accuracy problems are unlikely to change much from week to week, so the trends probably are accurate.

re: Bing gains, Google drops

James — Thu, 02 Jul 2009 13:41:08 GMT

Sorry: when I wrote "to identify individual users and tell which search engines they use", that should be "to identify individual users, and deduce which search engines a particular user uses from all the data against that user".