We all know Google does a lot of testing, in fact, I probably only cover less than 5% of the tests people email or send me that Google is running. I see tons and tons of UI tests, feature tests, color changes, ranking changes and more. So when Google sends things are constantly changing in search - they are not lying.
The issue is defining what are UI and feature changes versus core algorithm changes. I like to cover the ranking changes and then Google comes back and says we make thousands of changes to search every year. Of course they do, but what percentage of those changes are ranking specific? A much smaller number.
Anyway, on the new how search works site that Google just revamped, Google documented the raw number of those changes to the search results.
Glenn Gabe pulled the metrics from the page and posted them on Twitter. The page that has this is over here. In summary:
- Google quality raters conducted 130,336 search quality tests this past year
- Google ran 18,015 side-by-side experiments in search
- Google tried 9,800 live traffic experiments which hit about 1% of the searchers
- Google ultimately launched only 1,653 of them based on all those tests
Year, only 1,653 launched fully but again. those are both UI, features, search rankings and more.
Here is a GIF screen capturing these metrics so we have it for when/if Google changes these metrics for next time:
Forum discussion at Twitter.