TrustRank is a concept that attempts to separate good pages from bad. It's based on the assumption that good pages never link to bad ones. The whole process begins with identification of a (relatively) small number of "seed pages" that are evaluated manually. Then, a bot will crawl those pages looking for links to other pages, then crawling those pages, etc. The further a page is removed from the seed page, the lower its trustrank. While many people claim that TR is used by Google to rank pages, I don't believe it to be the case. In my view, trustrank remained one of the concepts that Google considered but never implemented on a larger scale.
TrustRank is a link analysis technique described in a paper by Stanford University and Yahoo! researchers for semi-automatically separating useful webpages from spam
Trust Rank is concept by Yahoo. The value is given for a page by considering the avoidance of spam. The page without spam will have a good trust rank.
TrustRank is a link analysis technique described in a paper by Stanford University and Yahoo! researchers for semi-automatically separating useful webpages from spam.[1] Many Web spam pages are created only with the intention of misleading search engines. These pages, chiefly created for commercial reasons, use various techniques to achieve higher-than-deserved rankings on the search engines' result pages. While human experts can easily identify spam, it is too expensive to manually evaluate a large number of pages. One popular method for improving rankings is to increase artificially the perceived importance of a document through complex linking schemes. Google's PageRank and similar methods for determining the relative importance of Web documents have been subjected to manipulation. TrustRank method calls for selecting a small set of seed pages to be evaluated by an expert. Once the reputable seed pages are manually identified, a crawl extending outward from the seed set seeks out similarly reliable and trustworthy pages. TrustRank's reliability diminishes as documents become further removed from the seed set. The researchers who proposed the TrustRank methodology have continued to refine their work by evaluating related topics, such as measuring spam mass.