TrustRank

TrustRank is an algorithm developed to help search engines distinguish trustworthy, high-quality websites from low-quality or spam websites.

Its origins date back to a research paper published in 2004 by researchers at Stanford and Yahoo!, who outlined the basic concept: “trustworthy” web pages tend to be linked to other “trustworthy” web pages.

In practice, then, the basic idea was to create a system based on a set of manually selected “trusted” pages and to use the linking distance from these trusted pages as an indicator of the likelihood that other pages on the web are trustworthy. The “closer” (in terms of backlinks) a page is to a trusted page, the greater the likelihood that it is itself trustworthy, and the more a site is linked from websites that are considered high quality and trustworthy, the higher the TrustRank will be.

Google has never officially confirmed the use of TrustRank as part of its algorithm, but it is widely acknowledged that similar concepts of trustworthiness and authority have been built into its ranking algorithms, particularly the PageRank system.