“Web spam pages use various techniques to achieve higher-than-deserved rankings in a search engine’s results. While human experts can identify spam, it is too expensive to manually evaluate a large number of pages. Instead, we propose techniques to semi-automatically separate reputable, good pages from spam. We first select a small set of seed pages to be evaluated by an expert. Once we manually identify the reputable seed pages, we use the link structure of the web to discover other pages that are likely to be good. In this paper we discuss possible ways to implement the seed selection and the discovery of good pages. We present results of experiments run on the World Wide Web indexed by AltaVista and evaluate the performance of our techniques. Our results show that we can effectively filter out spam from a significant fraction of the web, based on a good seed set of less than 200 sites.” Stanford InfoLab Publication.
Layman language of TrustRank formula can be found at http://www.umbrella-consultancy.co.uk/art1-trustrank.htm
TrustRank Explain Starts Here
If someone with a red (negative) reputation votes for you (good or bad), it doesn’t affect your reputation, because in the eyes of the system they are not trusted because others who ARE trusted have said so. While a vote (good or bad) from someone with many squares of reputation can lift you up on high, or condemn you to the fiery furnace, while votes from those with one or two squares of reputation will count, but not for much. This is a simplified form of TrustRank.
It is my belief that TrustRank will compound so that the sum of the whole will be greater than the parts. so if a site got links from a seed site it would be worth x, but a site with links from two seed sites could be x +y + compounded trust value.
Below is a graphical representation of how it might work, but I have for simplicity not added the compounding value, and have used round numbers. Google Page Rank uses a whole number of 1 as a base for each page, and a €™voting value€™ of .85 of the Page Rank value. (This being the result of the .15 dampening factor applied to all pages when determining the value of outbound links from a page).
So the old adage of build quality content that people will want to link to, means more than ever now.