" Not everything big, old and lumbers, is necessarily a dinosaur".
This statement took a capital meaning search engines constructors, aiming for their efforts to exceed the expectations of the internet users regarding the speed and the relevance in the information displayed, as the more the number of users as is a continuous growth- only the United States of America, the percentage recorded in February 2007 is 19% higher compared to February 2006.
What is a search engine?
The search engine solution is the proper solution for choosing the right information, out of the immense mass of relatively disorganized and documents on the Web, and making it available, according to the user's particular needs. It allows a search based on certain search criteria and obtain results that meet that criteria. Basically, the search engine"searches" and "delivers" information, revolutionizes the way people work with it.
The advantages of this practice of information are multiple. On one hand the global character of information- search and results, not go beyond the territorial and time boundaries, search engines have the ability to work with texts that are rapidly changed and showing the updated results,on the other hand the relevant information and the speed of only a few seconds needed to obtain them.
How does a search engine works?
The search engine's performance regarding the relevant information displayed, is the result of an own indexing and listing algorithm of web pages. Most of these search engines, including Google, are based on a division of computers whose main task is to index the words in each document and the information is stored in an optimal format. The storage pattern is generally tree, so that when a user makes a request by certain keywords the result takes into account the entire tree of thet keyword gradually eliminating what does not meet the criteria. However the process is not entirely congruent. Due to the fact that 95% of the text on the Web is composed of approximately 10,000 words, many of the pages that include the words listed are in the significant category causing an extremely large amount of high results. Selecting the pages based on their relevance, imposed creating ways of ranking the pages depending on their importance, without neglecting the basic criteria of the search, and finally placing the most important pages in the top of the list.
To limit the error rate associated with this procedure, the responsibilities of the classification were assigned to automatic tools evaluation based on altgoritmic calculation. In fact, Google claims that "the service value is determined by data clasification". The idea developed by PageRank's creators, Sergey Brin and Lawrence Page is that: the importance of a page is certified by the number of pages that lead to it and their relevance. In other words, the evaluation is statistically.
The specialistst in the field, recommend simultaneous using of more search engines, for obtaining the best results. The search engines use more that 150 algorithms for fuguring the results relevance.
The most important search engines are:
1. Google SearchEngine ( www.google.com)
The researches position Google as the leader among the search engines, with a percentage of 45% of all search. Its success is mostly due to the concept of Google links regarding its popularity and PageRank. The number of websites and web pages related to a particular page is measured by PageRank, based on the premise that the pages you want and quality pages are linked to one another. Google orders its results by numerical criterion of the websites that are linkeed to every page found. The "remembering" algotithm of the place where the cross-links are indexed and grouping them into categories is extremely important in the long term. PageRank is based on the "criteria analysis", developed in 1950 by Eugene Garfield of the University of Pennsylvania.
Besides the standard Internet search, Google provides specialized searches such as image, or video blog. The Watch search engine, in reccomends Google searches for news. Accessing Google Lab you can try beta versions or even new search tools.
2. Yahoo! Search Engine ( www.yahoo.com)
Surprisingly, the Yahoo! search engine enjoys a higher popularity than MSN or Windows Live Search, being plased, in many comparative studies on the second place, not only for the relevance of results but also for beign user friendly. Although users prefer Google in the Keynote System, they like Yahoo especially when it comes to image searches or local searches. The concept for the development of Yahoo! belongs to the founders, David Filo and Jerry Yang, from Stanford University. They began the research in a trailer on university campus in February 1994 dedicating more time to list their favorite sites than for the work of their masters dissertation. The list became too long and too wide so they have divided it into categories. When these categories were to full they developed small subgroups, and so was born the fundamental idea for Yahoo!. In 2002, Yahoo! bought Inktomi and Overture in 2003, which owned AlltheWeb and AltaVista. Although it had its own search engine, Yahoo! continued using Google to offer the results on Yahoo.com home page. However, in 2004, Yahoo! launched its own search engine combining technologies of previous purchases.
3. MSN Search Engine ( www.live.com)
Owned by Microsoft, MSN Search Engine paradoxically, occupies the last position according to Keynote Studies tests because characteristics of difficulty of use, but remains the first, in front of Google for relevant information. The reports regarding the beta version Windows Live Search, said that "there is a big improvement for MSN Search-flexibility in terms of facility in use". Windows Live Search displays results on one page. Windows Live Search allows you to create model of your own search engine. A beta version of a mobile search engine is currently in development for PDAs, Smartphones and mobile phones.
4. Ask.com (ask.com)
Ask.com initially called Ask Jeeves , was the first commercial search engine "question - answer" for the World Wide Web. Is owned by IAC. In 2006, it became the 4th search engine in the world. Ask.com has a certain advantage because the top results are usually from highly rated web sources. The results include several cross-links to rafining the search.