Today Google rolled out

“Panda”

algorithmic improvement globally to all English-language Google users. Google announced that high-quality sites algorithm goes global, incorporates user feedback on Monday.

Today we’ve rolled out this improvement globally to all English-language Google users, and we’ve also incorporated new user feedback signals to help people find better search results. In some high-confidence situations, we are beginning to incorporate data about the sites that users block into our algorithms. In addition, this change also goes deeper into the “long tail” of low-quality websites to return higher-quality results where the algorithm might not have been able to make an assessment before. The impact of these new signals is smaller in scope than the original change: about 2% of U.S. queries are affected by a reasonable amount, compared with almost 12% of U.S. queries for the original change.

According to Google, the algorithm is very accurate at detecting site quality. Now, if you believe your site is high-quality and has been impacted by this change, we encourage you to evaluate the different aspects of your site extensively.

Better review Google’s quality guidelines or asked questions in Webmaster Help Forums.