TrustRank is an algorithm created to differentiate good and bad (spam) sites and help search engines rank pages in search. TrustRank determines the likelihood that pages are reputable (i.e. a nonspam).
It was first introduced by Zoltan Gyongyi and Hector Garcia-Molina of Stanford University and Jan Pedersen of Yahoo! in their paper “Combating Web Spam with TrustRank” in 2004. Their main idea was that PageRank, as a quantitive metric, was subject to manipulations and was not enough to measure the trustworthiness of a website.
The main concept of TrustRank is that good pages seldom point to bad ones.
The input is set of human-reviewed reputable and trusted “seed” sites. Then the outgoing links from these websites are crawled. And the less link “hops” it takes to reach a given page on a web from these seed bwebiste, the higher its TrustRank.
The short answer would be “Not exactly…”
Although you can find a lot of mentions of Google TrustRank on the web, it’s not corect to say that Google is using the TrustRank from the research paper mentioned above. This concept was patented by Yahoo under the name Link Based Spam Detection and Google had no right to use it.
Google also used the term “TrustRank” and even trademarked it in 2006. Hoever it was a name of an anti-phishing filter, so Google’s TrusRank very different than what Yahoo was working upon.
However, Google has a patent named Search Result Ranking Based on Trust:
The trust ranks are used to determine trust factors for the respective documents. The trust factors are used to adjust the information retrieval scores of the documents.
PageRank is just one of the “trust-type” algorithms used by Google. Apart from “trust” Google uses other words like “reputation” and “authority.”
SEOs believe that the following factors may be contributing to the website’s trustworthiness in the eyes of Google: