QUOTE(projectphp @ Nov 7 2005, 08:09 PM)
...PageRank is used to measure importance and that it is used in conjunction with other ranking factors... Google doesn't use (PageRank) to rank search results...
So, what you meant to say, was that PageRank alone isn't used to rank pages?
I didn't mean to say anything other than what I have said, and I haven't said anything inconsistent about this.
Regarding the purpose of PageRank...
But for what purpose? Every factor measured makes a SERP ordered the way it is. Every single one.
PageRank is named for Larry Page. It is his method of determining which Web sites are more important than others with respect to the general user community. The algorithm has nothing to do with sorting results for search queries.
PageRank (the measurement of a document's importance as determined by the citations from other documents) is a potential weighting factor. It can have a reasonable impact on otherwise equally relevant documents.
Relevance, with respect to resolving a search query, has to address the relation of a document's data to the query. How many pages link to a page, how "important" those pages are, has absolutely no bearing on whether a page's data is relevant to the query.
The official White House biography for President Bush doesn't come up in the 1st 3 results (for "miserable failure") because of PageRank. It comes up because there are thousands of links pointing to that site with the anchor text of "miserable failure", thus associating those words with that document. That is, those links assert that the text "miserable failure" is associated with that document. Its data includes both on-page and off-page factors.
(Larry)PageRank just says, "Hey, if you start randomly clicking on links, there is a probability of 1/X times some other stuff that you'll end up on the official biography of President George W. Bush".
You are far more likely, in any random surfing session, to end up on a site like Yahoo! or Google when you start over. PageRank also assumes that will happen (and it does seem to be a pretty solid assumption, if I may base that evaluation on my own surfing habits).
PageRank is all about measuring the probability that you'll randomly reach any given page. It has nothing to do with how search results are determined.
Somewhere along the way, while setting up the original Google search engine, Page and Brin decided, hey, maybe we can factor in this importance ranking value and use it to affect search results. So, they gave it a shot.
It worked really well on university content and spam.
And then they started making changes to the whole system.
Today, we don't know exactly what Google is doing, but when you look at the entire
original "Anatomy of a Hyper-Textual Search Engine" paper, you see that they were not using PageRank to sort the results to begin with. So, they certainly are not doing that now (except with the directory).