Unexpectedly, yesterday Google released an update for the Top Search Queries in the Google Webmaster Tools improving the tool to match the expectation of SEOers (at least they matched mine).
We should all appreciate that ranking should be no longer considered a strong KPI, though it’s still one of the core metrics used to assess the performance of an SEO campaign.
In the old days, Google was reporting just the average position of all URLs from a site and for a given query. A real mess, considering the continuous fluctuation a keyword is exposed.
And probably it will continue to be a mess as they will continue to make the average of the position, but in this case they will consider only the top position a URL has appeared in.
How much data points they now consider is still a mystery, but an interesting aspect it emerges from the example they provide is the fact they seems to take in consideration the personalized search as a factor. As far as I reckon this information has never been disclosed previously.
From their site:
"Let’s say Nick searched for [bacon] and URLs from your site appeared in positions 3, 6, and 12. Jane also searched for [bacon] and URLs from your site appeared in positions 5 and 9. Previously, we would have averaged all these positions together and shown an Average Position of 7. Going forward, we’ll only average the highest position your site appeared in for each search (3 for Nick’s search and 5 for Jane’s search), for an Average Position of 4."
This change won’t affect historical data at all but only the Top Search Queries data going forward, hence all the reports you’ve done so far don’t require to be updated.