Chapter 1: Introduction of the topic background

The Internet has been created to share information and to communicate with each others.

It is hard to evaluate how big is the Internet, estimations among companies are very different, it varies from 15 to some 30 billion Web pages. (Cf. Koch, P. / Koch, S. (2009). How big is the Internet?.)

The number of websites is increasing everyday and estimated at more than 600,000,000 (Internet Systems Consortium. (2009). The ISC Domain Survey Internet Systems Consortium.) for 2009 with a constant augmentation since the creation of the world wide web.

Internet Domain Survey Host Count January 1994 - January 2009

Websites are used now in diverse manners if it comes to be a standard for companies (enlargement of their business activity, new opportunity for advertisement) it is also a space for many individuals (blog phenomenon).

Do you use a personal blog?

(USC Annenberg School. (2008). The impact of the Internet.)

A study realized on 29 countries shows that almost 25% of Internet users under 34 year-old are using a blog, this trend is moreover growing since 2003.

The vulgarization of the Internet and the fact that anyone can create his own website for free increased drastically the number of contents. The explosion of social networks (Facebook, Hi5…), blogs (Wordpress, Blogger, Myspace…), microblogging (Twitter) are changing the nature and fabric of the world wide web: from an Internet built by a few thousand of individuals we moved to one made by millions. (Cf. UCL. (2008). Information behaviour of the researcher of the future.)

If we take into account that searching is after e-mails the biggest activity which is made of the Internet: (USC. (2008). Annual Internet Survey by the Center for the Digital Future.)

How frequently do Internet users participate in the most popular activities?

We can then understand that more sophisticated tools are needed to find the right information on the Web.

So far we access to websites through three ways:

• Direct access (for example entering directly the URL in the address bar, clicking on a bookmark);
• External links (access to a website through the link of another website, this is the case in most of websites, catalogs, advertisement);
• Through Search Engines;

By using only the first two options one cannot browse the Internet normally. It has been said as well that the first way is disappearing more and more in profit of search engines. (cf. Ohayon, O. (2008). Google, moteur de recherche ou moteur de navigation?.)

A search engine is then indispensable in order to crawl the web properly.