Google’s Random Surfer Is Now Reasonable
Not all links are equal – and some links are more likely to be followed than others. Google’s new PR
patent, granted on May 11 reflects that.
An excellent post by Bill Slawski explores the recent patent awarded to Google, Google's Reasonable Surfer: How the Value of a Link May Differ Based upon Link and Document Features and User Data
The patent revises how Google regards a random surfer - you may recall that the original formula for PageRank, was put simplistically a calculation of the liklhood of a random surfer to click on a link.
Google's new patent
sees the surfer differently:
Systems and methods consistent with the principles of the invention may provide a reasonable surfer model that indicates that when a surfer accesses a document with a set of links, the surfer will follow some of the links with higher probability than others.
This reasonable surfer model reflects the fact that not all of the links associated with a document are equally likely to be followed. Examples of unlikely followed links may include “Terms of Service” links, banner advertisements, and links unrelated to the document.
Slawski’s post goes on to examine the characteristics of a link and what factors influence its value, including the number or links in a document, its position on a page or in a list, the number of links, the presence of other content. User behavior and its impact on PageRank calculation is also explored.
For serious SEOs, I believe this post and the patent is a must study. The post is a good place to start: http://www.seobythesea.com/?p=3806