Partition of Search Engines
Partition of search engines
Search engines based on an analysis of the content of the page
Since the Internet is growing much faster than any group of people can go katalogować, and because of defects directories (for example, under the slogan could be located thousands of pages), created a search engine, which przeszukują analyzing the content of Internet sites. When you give a search engine query, she will respond to it links to pages that it finds, depending on the algorithm used, as the most appropriate.
Search engines based on this principle can cover a much larger part of the network than directories. Unfortunately, they are very vulnerable to abuse by the user instead of useful information gets links on the parties do not have anything in common with his query. Wyspecjalizowały Particularly in this part of pornography.
Search engines based on an analysis of the network topology
To counter this, search engines have begun to apply the analysis of the network topology. So party shall be deemed to be equivalent to the query "britney spears," if many pages on "britney spears" linked to it. Page porno naked pictures of Britney, regardless of its own content, and regardless of the total number of links (mostly from other parties porno) on it, it will not be thus considered to be related to the topic. And if you ask the question "britney spears nude", the party will be deemed to be important because it links the many pages about "nude".
The initial significance on the basis of simple heuristics, after which normally uses the algorithm randomly jumping on the links.
The first search engine, which has used advanced algorithms and analysis of network topology was Google
Search engines based on an analysis of topologicznej are often considered to be very resistant to fraud. In fact, relatively czestym attack are spam-automatic systems for the exchange of links. Another form of attack is to create a large number of densely linked pages, of which all on the same topic. It is however difficult task and requires a substantial amount of work, and modifying heurystykę initial values can be significantly reduced this proceed, the scale on which the event is minimal.
Search engines based on the principle of auction sites
Another idea is introduced by Overture system, where the parties pay the search engine a few cents for each click, and the seats are bid side - which gives more per click is higher on the list of results. The items are paid marked as such, along with price. This system is beneficial to the owners of the parties - they only pay for entry is not for impressions.
The authors argue that it is also beneficial to the user, because the only parties that offer something useful in the field can afford such advertising. On the other hand, many non-parties is useful, and even in the commercial sides of the results will often nieoptymalne - for example, on such advertising can not afford the parties, which have low margins and offer products at low prices, but only those that have higher margins and offer products more expensive.