Google's search improvement team announced that they've made a major change to the algorithm that shapes your Internet experience. While, as always, they won't say specifically what they've come up with, they say the update will "reduce rankings for ... sites which are low-value add for users, copy content from other websites or sites that are just not very useful." It will also boost rankings for "sites with original content."

I'm excited to see how the change plays out, and I hope that one day soon, some of the technical details will spill out. Because while humans are pretty good at detecting the basics of "quality," machines haven't been. As you'll read in the excerpt from the announcement below, though, the humans and Google's algorithm appear to be in pretty good agreement about what's bad and what's good.

Many of the changes we make are so subtle that very few people notice them. But in the last day or so we launched a pretty big algorithmic improvement to our ranking--a change that noticeably impacts 11.8% of our queries--and we wanted to let people know what's going on. This update is designed to reduce rankings for low-quality sites--sites which are low-value add for users, copy content from other websites or sites that are just not very useful. At the same time, it will provide better rankings for high-quality sites--sites with original content and information such as research, in-depth reports, thoughtful analysis and so on...

It's worth noting that this update does not rely on the feedback we've received from the Personal Blocklist Chrome extension, which we launched last week. However, we did compare the Blocklist data we gathered with the sites identified by our algorithm, and we were very pleased that the preferences our users expressed by using the extension are well represented. If you take the top several dozen or so most-blocked domains from the Chrome extension, then this algorithmic change addresses 84% of them, which is strong independent confirmation of the user benefits.

Read the full story at Google Blog.