How Does Google Rank Pages?

Most successful businesses start from humble beginnings and the best search engines are the products of student projects at universities. The research project by two Stanford University students of PhD; Larry Page and Sergey Brin is an ample manifestation of the above stated fact.

When the two students started working on their project, many successful search engines were operating and AltaVista was leading the market. To grab the growing number of internet users, every search engine was trying to index the bulk of web pages without any consideration for quality.

The idea of ranking the most relevant page on the top fascinated Larry Page. He was obsessed with this point, which all the other search engines missed; namely the quality of search engine indexing and ranking.

The hypothesis of Page’s research thesis was based on the argument; a link from one site to another was akin to an academic citation and the anchor text attached with the link was like an annotation. He assumed that if we could single out the sites cited the most for any particular subject, we could also index the subject area vis-à-vis its significance or authority.

Page was fascinated by a fundamental weakness in the original design of Tim Berners-Lee’s web. He noticed that it was very easy to see the links from a website but it was very hard to see the backlinks to the site. BackRub, Google’s former name, was using the method of cataloguing all the links on the web to give authority to a site on a given subject. Page did not intend to launch his own search engine at this point but his curiosity in this field lead him towards the creation of a new type of crawler. This crawler was based on a system of link-ranking that is still considered to be the best type of page ranking.

What is Important for Google?

The core system in Google’s algorithm is based upon the same link-ranking system developed by Larry Page at Stanford. The system is called PageRank. It is named after the inventor of this system (Larry Page) and not the pages of the web.
Google has explained PageRank in the following way:

“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…”

The explanation shows PageRank in the form of a big electronic voting system. The page which gets the highest number of votes will go to the top of PageRank scale of 0 to 10. In simple words, the importance or authority of a page is determined by the quantity of links.

But, this is only one side of the picture. Google further explains it in the following way:

“Google looks at considerably more than the sheer volume of votes, or links a page receives; for example, 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.’” Using these and other factors, Google provides its views on pages’ relative importance.’

In this voting analogy used by Google, PageRank is not a voting machine that gives equal importance to all the links. The vote by the sites which already has accumulated large quantities of votes has greater authority than the relatively unknown sites. In other words, not only the quantity of links but also the quality of links is important for Google PageRank.

What is Relevant for Google?

The relevance of material in a web page also holds prime importance for getting top PageRank. We can illustrate this with the help of a simple example. Every body knows that the Guggenheim Museum, New York is a popular art gallery and is often sited by many as an important resource. Guggenheim is a gallery for modern art and if you look for seventeenth century art, you will not be able to find contents from this gallery.

However, if you are searching for some particular artist that is relevant to the Guggenheim collection, you will certainly find it among the top ranking pages. For example, you can try ‘Piet Mondrian’ in Google or Yahoo! The results will show Guggenheim in the top 10. How does Google rank this? This is explained by Google it self; the search engine “goes far beyond the number of times a term appears on a page and examines dozens of aspects of the page’s content (and the content of the pages linking to it) to determine if it’s a good match for your query.”

In simple words, Guggenheim page ranks in the top 10 for the word Piet Mondrian because a lot of galleries have linked to the text Mondrian on the Guggenheim page.

This complicated process is called text matching. The importance of these text links is based upon the quality of the link. The quality of link is based on the relevance of anchor text with the key phrase. The relevance of anchor text determines the quality of the link. The closer the anchor text to the key phrase, the link will be considered to have more quality.

What is deemed reliable by Google?

Google gives more weight and assigns greater ‘trust’ to a site in its algorithm which has more quality links. It is often called TrustRank. Any links from authoritative websites established in the earlier days of web, Yahoo! Directory and Open Project Directory, and websites with domains like .gov and .edu are considered to carry greater reliability and weight. These links can enhance the PageRank of a website.
Final word on Google page rankingBriefly, we can say that today Google’s algorithm uses all the factors like relative importance, relevance and reliability to determine the authority or significance of a web page. The PageRank algorithm considers link quantity and the importance of the link source to determine the significance of a page. The TrustRank determines reliability of a page using age of the page as a proxy. Relevance of the text is determined by the Text Matching algorithm using relevance of the source and site and various other factors. All these algorithms work together with different filters to produce high quality results just in milliseconds for any request from the web browsers.

Page Rank

June 18, 2008 | Filed Under Basic Keyword Research 

Comments

One Response to “How Does Google Rank Pages?”

  1. Keyword Tools Conspiracy Theory | Taknique on October 25th, 2008 3:51 am

    […] months after launching and easily ranking first in Google in my target keywords, I learned my first big lesson in keyword research. That is— don’t […]

Leave a Reply