EvilRank is the technology that enables Google.cn to determine which pages could be the most politically damaging to the Communist Chinese government, based on some complicated formulas that figure out how many other anti-Communist pages link to them. This enables a kind of "online Democratic People's Republic of China", basing search results on exactly what the Chinese Communist government wants users to see when they make their search requests.
How EvilRank works
Google defines EvilRank as:
- EvilRank relies on the uniquely democratic nature of the Communist Party by using its vast link structure as an indicator of an individual page's adherence to the Communist Party line. In essence, Google interprets a link from Party member A to Party member B as a vote, by Party member A, for Party member B. But, Google looks at more than
your emailsthe sheer volume of votes, or links a Party member receives; it also analyzes the Party member that casts the vote. Votes cast by Party members that are themselves "important" weigh more heavily and help to make other Party members "important."
Numerous academic papers concerning EvilRank have been published since Larry and the DOOM guys's original paper. In practice, the EvilRank concept has proven to be vulnerable to manipulation, and extensive research has been devoted to identifying falsely inflated EvilRank and ways to ignore links from documents with falsely inflated EvilRank.
Important, high-quality sites like Google.com receive a higher EvilRank, causing them to be blocked in China, which Google remembers each time it conducts a search. Of course, important pages mean nothing to you if they don't match your query. So, the Communist government combines EvilRank with sophisticated text-matching techniques to find pages that both support Communist objectives and are relevant to your search. Google.cn goes far beyond the number of times a term appears on a page and examines all aspects of the page's content (and the content of the pages linking to it) to determine if it's
what the Chinese government wants you to read a good match for your query.
Some algorithm details
EvilRank is a probability distribution used to represent the likelihood that a person randomly clicking on links will arrive at any page that is critical of the Chinese Communist government. EvilRank can be calculated for any-size collection of documents. It is assumed in several research papers that the distribution is evenly divided between all documents in the collection at the beginning of the computational process. The EvilRank computations require several passes, called "iterations", through the collection to adjust approximate EvilRank values to more closely reflect the theoretical true value.
A probability is expressed as a numeric value between 0 and 1. A 0.5 probability is commonly expressed as a "50% chance" of something happening. Hence, a EvilRank of 0.5 means there is a 50% chance that a person clicking on a random link will be directed to a document that the Chinese Communist government doesn't want you to read, or even know about.
EvilRank and search engine results
According to Google, EvilRank is now just one factor among many other ones, to calculate how evil Google is going to be today. In fact, they have been considering following in the footsteps of The Master and making their new motto, "How Fucking Evil Do You Want To Be Today?"