Google's search algorithm is almost constantly changing. One of the search engine's most recent changes, termed Panda 4.1, went into effect at the end of September, announced on the Google+ page of Pierre Far, and shared by Matt Cutts, the Googler in charge of web quality, web spam, and search optimization. The original post notes that the update affected somewhere between 3% and 5% of search queries, often improving the rankings of some smaller sites with high quality content.
A post on The Moz Blog describes how the changes affect some search results. According to the post's analysis, sites which benefited most from the change featured trustworthy, insightful original content written by experts. On the other hand, sites without this kind of content have often seen their results adversely impacted. (Click here to see more details on The Moz Blog.)
Some online marketers have collected suggestions about how to keep Panda 4.1 in mind when creating useful content. A recent article on Marketing Land, for instance, suggested that online marketers should consider creating more high quality content to help make every page of a site useful for visitors, in a way that aligns with the suggestions offered in Google's own Search Engine Optimization Starter Guide.
"Panda update rolling out" [Google+]
Panda 4.1: The Devil is in the Aggregate [The Moz Blog]
How Google's Latest "Panda" Algorithm Should Change Your Content Strategy [Marketing Land]