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Getting the website at the top of search result is always a target of an web analyst and SEO optimizer. Hence its important to understand the concept behind the Page Rank which is the way in which search engine ranks your content. Here is the technical detail over how Yahoo and Google ranks the content.

PageRank (also referred as PR) is a link analysis algorithm, named after Larry Page, used by the Google Internet search engine that assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of “measuring” its relative importance within the set. The algorithm may be applied to any collection of entities with reciprocal quotations and references. The numerical weight that it assigns to any given element E is also called the PageRank of E and denoted by PR (E).

Google figures that when one page links to another page, it is effectively casting a vote for the other page. The more votes that are cast for a page, the more important the page must be. Also, the importance of the page that is casting the vote determines how important the vote itself is. Google calculates a page’s importance from the votes cast for it. How important each vote is is taken into account when a page’s PageRank is calculated.

PageRank does matter in the current scenario of web sites usage and penetration to diverse domains of the world because it is one of the factors that determine a page’s ranking in the search results. Although this is not the only factor that Google uses to determine a web page’s importance, but it is definitely an important one.

Point to be noted is that not all links in a page are counted by Google. For instance, they filter out links from known link farms. Some links can cause a site to be penalized by Google. They rightly figure that webmasters cannot control which sites link to their sites, but they can control which sites they link out to. For this reason, links into a site cannot harm the site, but links from a site can be harmful if they link to penalized sites. So be careful which sites you link to. If a site has PR0, it is usually a penalty, and it would be unwise to link to it.

How is PageRank calculated?

To calculate the PageRank for a page, all of its inbound links are taken into account. These are links from within the site and links from outside the site.

PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn))

This is the original equation published when PageRank was being developed. It is probable that Google uses a variation of it but it is not known what it actually is. In the equation ‘t1 – tn’ are pages linking to page A, ‘C’ is the number of outbound links that a page has and ‘d’ is a damping factor, usually set to 0.85.

Thinking in a simpler way, we can draw an analogous equation as:

A page’s PageRank = 0.15 + 0.85 * (a “share” of the PageRank of every page that links to it)

Where, “share” = the linking page’s PageRank divided by the number of outbound links on the page.

A page “votes” an amount of PageRank onto each page that it links to. The amount of PageRank that it has to vote with is a little less than its own PageRank value (its own value * 0.85). This value is shared equally between all the pages that it links to.

Yahoo PageRank

Yahoo WebRank is basically a rank assigned to a URL by Yahoo on a scale of 0-10. It was introduced as a Beta feature of the Yahoo toolbar couple of years ago. Since it was an experimental feature it is no longer available as a part of their toolbar.  On its patent statement, yahoo uses both the terms PageRank and TrustRank, however, it is interesting that both the terms are trademarks of Google. According to Yahoo, PageRank is a family of well known algorithms for assigning numerical weights to hyperlinked documents (or web pages or web sites) indexed by a search engine. PageRank uses link information to assign global importance scores to documents on the web. The PageRank of a document is a measure of the link-based popularity of a document on the Web.

In the patent application, Yahoo explains how they want to find spam farms with the help of PageRank and TrustRank. A spam farm, according to Yahoo, is an artificially created set of pages that point to a spam target page to boost its significance. Trust-ranking (”TrustRank”) is a form of PageRank with a special teleportation (i.e., jumps) to a subset of high-quality pages.

Using the predefined techniques, a search engine can automatically find bad pages (web spam pages) and more specifically, find those web spam pages created to boost their significance through the creation of artificial spam farms (collections of referencing pages). In specific embodiments, a PageRank process with uniform teleportation and a trust-ranking process are carried out and their results are compared as part of a test of the “spam-ness” of a page or a collection of pages.

As the Yahoo’s page rank was launched and continued for a short period of time, we cannot assess its effectiveness in today’s time. If your site is running since several years, it might still show a Yahoo WebRank otherwise, it is not existent today.

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