TrustRank: TrustRank is an algorithm that determines search relevancy by putting additional weighting on links posted by trusted seed websites. These generally include websites belonging to governmental or educational institutions or major corporations.
This link analysis technique provides a quick and semi-automatic way for researchers to separate useful webpages from spam pages.
Spam pages are often created with the specific aim to mislead search engines. These pages are usually created for commercial reasons and utilize different techniques to achieve search engine rankings that are higher than the content actually warrants. Sites may also try to artificially increase rankings through complicated linking schemes.
Human experts can identify spam pages with a quick glance, but manually inspecting millions of pages takes time, so TrustRank automates part of the process. An expert selects several reputable seed pages manually, then an automated algorithm crawls outward from the seed set to find similar trustworthy pages.
As the crawler gets farther away from the seed set, it becomes a less reliable measure of a page or document's value. Google PageRank and other methods like TrustRank use similar methods to analyze the reliability and trustworthiness of various webpages.
There are several websites where companies can check their website's current TrustRank.