Search engine optimization (SEO)

Assume each circle above is a website and arrows are links from one website to another. Users can click on a link within website F to go to website B, but not vice versa. Search engines begin by assuming each website has an equal chance of being chosen. Next, crawlers examine which websites link to which websites and guess that websites with more incoming links contain information users need.

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Introduction

Search engine optimization (SEO) is the process of improving the volume or quality of traffic to web sites from search engines. This is accomplished using "natural" or un-paid ("organic" or "algorithmic") search results as opposed to search engine marketing (SEM) which deals with paid inclusion. Typically, the earlier (or higher) sites appear in search results or listings the more visitors it will receive. SEO may target different kinds of searching, including image search, local search, video search and industry-specific vertical searching. This gives a web site its digital presence.

Getting indexed

All of the leading search engines, such as Google, Bing and Yahoo!, employ crawlers to locate webpages for their algorithmic search results. Web pages that are linked from other search-engine indexed pages do not need to be submitted because they are automatically found. Some search engines operate a paid submission service that guarantees crawling for either a fee or based on cost per click. These programs usually guarantee inclusion in the database, but do not guarantee specific ranking within search results. Two major directories, the Yahoo Directory and the Open Directory Project, require manual submission and human editorial review. Google offers webmaster tools where an XML feed can be created and submitted for free to ensure that all pages are found, especially those that are not usually discoverable by automatically following links.

Search engine crawlers may look at a number of different factors when crawling web sites. Not every page is indexed by the search engines. The distance of clicks or pages from the root directory of web sites may also factor into whether or not they are crawled.

References

• Does SEO Die on Web 3.0? It certainly withers. Search Principle blog 2008.
• Google webmaster guidelines
• Wikipedia. Search engine optimization
• What is SEO? Definition of SEO and how it works

See also

• Answering health and medical reference questions
• CAPHIS | Top 100 Health Websites You Can Trust
• Consumer health information
• Multilingual resources for patients
• Patient education
• Top 100 Canadian Health Websites
• Top Ten (10) Canadian Health Websites 2010
• Top Social Media Websites in Medicine - 2012
• WikiPatient

Disclaimer

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