May 10th, 2007
Page Rank or "PageRank", is a term that describes a link analysis algorithm, created by the founders of Google (back in 1995 as part of a research project at Stanford, with a finished prototype in 1998), which helps to determine a web page’s search engine rankings for a particular keyword search. PageRank is just one of many factors that Google relies on to rank results in their index, but is worth noting as important because Google uses this as the basis for all their online search tools/offerings.
Essentially, PageRank (PR) is a number, anywhere from 0 to 10, assigned to and spread out among a set of web documents. For example, if you have a website with 5 pages, your index (home) web page might have a PageRank of 6, while your sub pages may have a lesser PR of 3 or 4 (being a little less popular / less in-bound links). Some documents on your site may not even have page rank at all. Again, PR is spread out amongst the pages on your web site to help Google’s search spiders and index know which pages are the most important pages (on your site) to show in their search results for key word searches. PR helps to show which pages are the most relevant and which ones are not.
How do I check my site’s PageRank? You can download the "Google Toolbar" and install it into either your Internet Explorer or Firefox web browser. The Google Toolbar has a PageRank meter that you can check whenever you browse to a particular URL, very handy.
How is PageRank assigned on your website? PageRank relies on the democratic nature of the world wide web in that links to a given web page count as "votes" for that webpage, the more votes you get, the higher the PageRank and the better your chances of ranking high. So if web pages "B" and "C" both link to page "A" then page"A" has 2 votes. Likewise if page "A" points to page "B" then page "B" now has a vote from page "A". It is thought that links from other web sites pointing at your web page are generally weighted more than links from your own internal web pages pointing back at your web site. Again, the more links you have pointing to your web page, generally a higher PageRank number is assigned to that web page. Google also takes into account the quality of the incoming links to your pages (links that are coming from web sites /web pages that have similar content and or theme as your web page) and not just the quantity.
PageRank is also thought to be based on a logarithmic scale of somewhere between a base 5 or 6, so your PageRank goes up when you reach a certain link level/threshold. If you are not familiar with logs don’t worry, here is a tutorial, and I will try to spoon-feed this to you 😉 For example: if PR was using a logarithmic base of 5, your web page will reach a PageRank of 3 when you have X number of links at or greater than 125 and less than 625 (125 <= X < 625). In this case the lower limit of 125 comes from 5^3 = 125 links, while the upper limit 625 comes from 5^4 = 625 links. Do you see how having your X number of links between 125 and 625 will always result in a logarithmic value of no less than 3 but no greater than 3? Another example, if you had 300 back-links to your web page, then obviously 125 <= 300 < 625, so the log base 5 of 300 will give you a number of something like 3.5439 (rounded off), which is no less than 3 but no greater than 3. But what if your link count gets bumped up at equal to or greater than 625, say at 626? Then it is thought your PageRank will increase from 3 to 4, since the number 626 gives a logarithmic result of exactly 4.0009933414339, which is no less than 4 and no greater than 4 while using a base of 5 🙂
The NoFollow hyperlink tag attribute is a new industry standard recently adopted by all major search engines to help people redistribute PageRank within their websites, i.e. stoping PageRank leaks from important pages to less important pages. It was also created to combat spam within blogs to help stop PageRank from being injected into third party sites that aren’t relevant, such as spam blog commentators who leave their web site URLs on blog entries in hopes of creating instant back-links, and ultimatley higher PageRank, to their web sites.
Also of note: there are web pages that rank higher in search results than other web pages that have a much higher PageRank – so PR is not an end all solution to where your web page ranks on a particular key word query. Besides, it wouldn’t make sense to base search results on one factor or one majority factor alone, people could game the system with ease by creating many spam back-links, resulting in spam search results = no good. PR just happens to be a single factor in the grand ranking scheme that Google has laid out.
If you remember only one thing about this article, remember this: PR can be used to tell the search engines which pages on your site are more important than others, depending on the keyword search context given. Read up more about how to tweak your web site’s PageRank to your benefit.
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