At Pleth we tend to keep a close eye on our clients search engine rankings, I personally devote about an hour each day to just Google Hacking to see where we stand on things. This week, I have had 2 separate unrelated clients ask me about Google PR, or PageRank so I am going to attempt to explain it here as best as I possibly can without getting too technical.
Google explains PR as the following:
PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page’s value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves “important” weigh more heavily and help to make other pages “important.
What this means is that a PageRank results from a “ballot” among all the other pages on the World Wide Web about how important a page is. A hyperlink to a page counts as a vote of support. The PageRank of a page is defined recursively and depends on the number and PageRank metric of all pages that link to it (“incoming links”). A page that is linked to by many pages with high PageRank receives a high rank itself. If there are no links to a web page there is no support for that page.
Google assigns a numeric weighting from 0-10 for each webpage on the Internet; this PageRank denotes a site’s importance in the eyes of Google. The PageRank is derived from a theoretical probability value on a logarithmic scale like the Richter Scale. The PageRank of a particular page is roughly based upon the quantity of inbound links as well as the PageRank of the pages providing the links. It is known that other factors, e.g. relevance of search words on the page and actual visits to the page reported by the Google toolbar also influence the PageRank. In order to prevent manipulation, spoofing and spamdexing, Google provides no specific details about how other factors influence PageRank. This information exists inside of Google’s “top secret algorithm”, and that is something that I will not try to go into on this blog post, those of you who have taken advanced mathematic courses will understand why, ha.
Hopefully this helps to explain PageRank. Here’s something interesting that I did not know until the other day, PageRank is a licensed and trademarked term but not by Google, it’s actually trademarked to Stanford University. I thought that this was interesting because it was actually Google who brought this terminology to the forefront of our industry.
To answer the ever so popular question, “Why did my website lose Google PR?”, here are a few possibilities:
- There are fewer websites (of value) linking to you.
- Websites that are linking to you have been devalued.
- Google’s PR Algorithm (top secret) may have been tweaked.
- Websites that are linking to you aren’t crawled by Google’s Bots.
Hopefully this helps…