Google PageRank
What is Google PageRank?
Google PageRank is an algorithm patented by Google that measures a particular page’s importance relative to other pages included in the search engine’s index. It was invented in the late 1990s by Larry Page and Sergey Brin. Google PageRank implements the concept of link equity as a ranking factor.
Google PageRank approximates the likelihood that a user, randomly clicking links throughout the Internet, will arrive at that particular page. A page that is arrived at more often is likely more important — and has a higher Google PageRank. Each page linking to another page increases the Google PageRank of that other page. Pages with higher Google PageRank typically increase the Google PageRank of the other page more on that basis.
To view a site’s Google PageRank, install the Google toolbar (http://toolbar.google.com/) and enable the Google PageRank feature. One thing to note, however, is that the Google PageRank indicated by Google is a cached value, and is usually out of date.
Google PageRank is just one factor in the collective algorithm Google uses when building search results pages (SERPs). It is still possible that a page with a lower Google PageRank ranks above one with a higher Google PageRank for a particular query. Google PageRank is also relevance agnostic, in that it measures overall popularity using links, and not the subject shrouding them. Google currently also investigates the relevance of links when calculating search rankings, therefore Google PageRank should not be the sole focus of a search engine marketer. Building relevant links will naturally contribute to a higher Google PageRank. Furthermore, building too many irrelevant links solely for the purpose of increasing Google PageRank may actually hurt the ranking of a site, because Google attempts to detect and devalue irrelevant links that are presumably used to manipulate it.
Google PageRank is also widely regarded by users as a trust-building factor, because users will tend to perceive sites with a high value as more reputable or authoritative. Indeed, this is what Google PageRank is designed to indicate. This perception is encouraged by the fact that Google penalizes spam or irrelevant sites (or individual pages) by reducing or zeroing their Google PageRank.
Other Page Ranking Algorithms
Google PageRank isn’t the only page ranking algorithm, but it is one of the most popular. Other algorithms include:
- The Hilltop Algorithm
- ExpertRank
- HITS Algorithm
- TrustRank