Customized results from search engines that are geared to the individual based on that person's past search preferences. It means two people searching for the same thing receive a different sequence of results. The term comes from the book "Filter Bubble: What the Internet is Hiding from You" by Eli Pariser. In the book's introduction, Pariser highlighted Google's December 2009 announcement that it would start using some 57 signals to determine the results it reports to users. Proponents say this delivers a better user experience, while opponents claim the information can be too slanted and not provide a sufficient variety of opinions.