The name PageRank, which is a trademark from Google, is a pun between Page Rank, rank of a page, and Larry Page, one of the two founders of the company, which owes his initial success with the implementation of an algorithm with the same name. This one classifies Web pages according to their popularity on the Web, therefore according to the number of link toward them.
It is about the algorithm described by Larry Page and Sergey Brin
and which is at the origin of Google.
Better PageRank will be obtained by a page with a greater number of links pointing on it but according also to PageRank these pages themselves have. If a page points on several others, the value which it brings is divided by the number of links. But the value which is acquired by links of quality being integrated into the page, it will be transmitted to the pages on which point this page.
In the act of page ranking, PageRank intervenes in a second time: in answer to a query, pages
are selected according to keywords they contain. Then the pages which contain
the same keywords are classified according to a whole of criteria among which
Thus it is possible to reach the top of the results with a null PR, as soon as one is alone to evoke certain keywords. On the other hand,on competing searches, PR is a crucial factor to reach the top.
The PR has also a role in the way a site is crawled:
"The number of pages that we crawl is roughly proportional to your PageRank."
We do not know whether this factor is relevant in 2014 as it now depends on other factors, the value given by Panda, the size of the site.
To know your PageRank, take in mind that it depends upon a group of keywords. To know the real ranking, perform searches with various keywords. The position of your page (when several match the request) gives the ranking: the top of list means for a ranking of 10. First page of search results means for 6-9 PR when lot of matches exists.
How is calculated the PageRank?
PageRank, or website ranking, is a notation from 0 to 10, given by Google to
each page of a website.
The higher is this value, the better will be the position of the page in results
of searches, among other pages that match the request.
A 5 points PageRank is Good. 7 points may be reached with valuable backlinks. The number of 10 points PageRank websites is very short!
The word PageRank comes both from "page ranking" and "Page" that is the name of one of the two authors of the algorithm (Serguey Brin and Larry Page).
PageRank does not depend on page content but links pointing to it (and outbound links to a lesser degree).
The authors of the algorithm, from the links between all the web pages, establish a chain of Markhov which gives the probability of reaching a given page in the shortest time possible.
To be simple, to get a higher PR, you must have many links pointing to your site, and mainly quality links from sites that then themselves have many quality links pointing to them.
The "vote" of a page is transitive, if A links to B , it enhances the importance of B, and therefore, if B links to other pages, it also enhances their importance.
Moreover, if a page points to several links, the weight it brings is divided by the number of links (including nofollow links that are discounted here).
Links between pages within a site are taken into account, and they tend to transfer the PageRank from a page to another.
Reference: "Deeper inside PageRank" by A.N. Langville et C.D. Meyer.
Improving the PageRank
There are however honest techniques to increase the PR of a site! One calls that "white hat" SEO or search engine optimization. The best way is to improve the quality of your pages, their originality, but also to review their design.
- Have a well defined topic for each page. It will contain a maximum of different keywords concerning this subject, with all possible synonyms to reach the most concerned visitors. The PR of a page depends upon a group of keywords, or several groups of keywords in the page, actually.
- Add only very relevant outgoing links on your pages, useful for visitors. But do not omit such links, they are part of the quality of a Web page.
- Put links between the pages of the same site, when they complement each other.
The algorithm of PageRank takes into account backlinks, and also the links of the site towards other pages.
It is a fact the initial algorithm is not used any more from a long time, that is said by Google, but it is confirmed by search engines that outgoing links, if they are relevant and if they point to authority sites, contribute to the ranking of a page.
- To obtain backlinks: create original contents, with an attracting presentation. Prepare and promote the site as described in the SEO tutorial. Get quality backlinks. Directories are not interesting. Give users what they expect is the best way to get links.
- Do not omit the <title> tag, the <h1>, <h2> and other sub-titles. All titles must be appealing, it is necessary that one wants to choose your link in the pages of results of search engines (that is taken into account for later position in the results).
- The text of anchors of internal links is important. It must contain significant words and in connection with the contents of the paragraph.
Bad practices to avoid
These artifices are generally detected automatically by Google or through request from competitor who denounce sites using such tricks. The sites using the so called "black hat" SEO can be placed on a blacklist and removed from the index.
One put in the page links invisible to Net surfers, for example with a white color on a white background, but that the robots of search engines take into account since they are unaware of the attributes of presentations like colors.
This is putting lot of hidden links into a web page (inside "no script" tags for example) to make more links to a friend website and improve its ranking. Once spamming is recognized, the two websites goes to the blacklist.
This is redirecting a page to a page in another website with a high PageRank, and this result in the source page to get the PR of the destination. The redirection is achieved by the use of the "refresh" meta tag. Visitors see the current page, but search engines see only the target page with the high PR.
This is known as a bug in the calculation of the PR, and is probably fixed now.
- When a page is redirected through the HTTP code 301, the PageRank is transmitted with a discount. This has been confirmed by Matt Cutts. The ratio of this reduction is the same than for a link, about 15%. We can say from experience that it is enough to lose one or more positions in results.
It is better to avoid changing the domain of a site if it is not absolutely necessary.
- If a page has many backlinks, when the content is changed, does it kill the value of these links (which makes sense since they were linked to the original content)?
We know that when a domain expired and bought by another Webmaster, PR is reset. This was communicated by Google.
In the case of change of content, it is a personal impression, things are perhaps worse, the change can be seen as a tactic of spam and the page penalized if it does not get new backlinks.
- Avoid the "nofollow" attribute, example: <a http://www.sitexxx.com rel="nofollow" >The site</a>, or lose 2 points of PageRank. Use the nofollow attribute only to pages that should not appear in Google's index, and not for other reasons.
- How Google determines the score of a page. All criteria taken into account beside the PageRank according to a patent deposited in April 2007 by Google.
- Google PageRank, what do we really know about it? List of rules and summary or articles and tools about PR. Not all is true in the article, for exemple: "Adding new pages can decrease Page Rank" is false.