Search Engines

A search engine is a program that helps finding informations stored on a computer system. Search engines may just search your own computer, a database or anything else where lots of informations are stored.
Many search engines are available via the internet. They allow you to search inside specific collections of informations.
An easy way to access search engines in the internet is the search box of the Firefox Browser .

Search engine examples

 Wikipedia hosts user-created encyclopaedias in different languages. Default is title search, full text searches are possible too.
Be aware that everyone can change the articles at Wikipedia. In most cases wrong informations are corrected pretty fast, but some articles are probably influenced by commercial or political interests.
Firefox Search Engine  Plugins for Wikipedia is an english/german dictionary. The search engine searches their english/german dictionary.
 more dictionaries
Firefox Search Engine  Plugins for dictionaries & translation

 Ebay offers public online auctions. You can buy and offer goods there. Their search engine searches the actual offers.
 more buy/sell

Web search engines

Web search engines base on human and/or computer created indices of existing websites. Only indexed websites will be found.

Web search engine examples

 Cuil is a search engine that organizes web pages by content and displays relatively long entries for the results. It claims to have a larger index than any other search engine. It went online in 2008.

 Delicious is a social bookmarking web service for storing, sharing, and discovering web bookmarks. The site was founded by Joshua Schachter in 2003 and acquired by Yahoo! in 2005. It has more than five million users and 150 million bookmarked URLs. You search the tags (keywords) of the users, which can be very individually, so follow the recommended and associated tags.
Exercise: ’search engines’ on delicious

 Google is the most popular web search engine but also often critisized. Be aware that Google is a commercial service! For example the pink highlighted first searchresults are paid commercials!
The language of the interface and the preferred search results are determined by the IP of the user and the preferred language setting of the Firefox browser.

 Yahoo also has a popular web search engine and also has been criticized for aspects of its business and practices, including paid inclusion, accusations of support of adware and spyware, and its cooperation with the Chinese government in enforcing internet censorship in mainland China.
Yahoo detects the location of the user and changes the interface language and the preferred search results according to the detected location.

 MetaGer is a german meta search engine. Meta search engines search in multiple search engines and combine the results.  more meta searchengines

There are many more web search engines. See  web searchengine and  list of search engines

How to use a web search engine

Useful keywords are essential for a good search query, so that you find what you are actually looking for. If the keywords are too unspecific, you will get lots of useless results. On the other hand a too specific search query may lead to no results.
You recognize a well done search, when you find the information within the first 20 results.

Most search engines can handle combined keywords in a search query.

  • Multiple keywords separated by space or + lead to a search for pages which contain all these keywords, also as part of a word, anywhere on the page, means in any order and there can be other content between the keywords.
  • If a phrase in a search query is enclosed into "", you will find exactly this phrase. All enclosed words must be in the same order and not separated.
  • Keywords separated by ~ have to be nearby each other.
  • Typing a - in front of a keyword excludes sites containing this keyword.

Many search engines have a special page for advanced searches. As an example: Google advanced search

Sometimes it helps to use different search engines and compare the results.

Exercise: What are you interested in? Specify well. Decide if you should rather use wikipedia, a directory like dmoz or a search engine.

You want to know more about this topic? Try the documentation of the web searching workshop of the UC Berkeley (USA)