วันศุกร์ที่ 27 มกราคม พ.ศ. 2555

Chapter 8 Search engines

 

What is Search engine?



 Basically, a search engine is a software program that searches for sites based on the words that you designate as search terms. Search engines look through their own databases of information in order to find what it is that you are looking for.



Are Search Engines and Directories The Same Thing?

Search engines and Web directories are not the same thing; although the term "search engine" often is used interchangeably. Search engines automatically create web site listings by using spiders that "crawl" web pages, index their information, and optimally follows that site's links to other pages. Spiders return to already-crawled sites on a pretty regular basis in order to check for updates or changes, and everything that these spiders find goes into the search engine database. On the other hand, Web directories are databases of human-compiled results. Web directories are also known as human-powered search engines.

How Do Search Engines Work?

         search engines are not simple. They include incredibly detailed processes and methodologies, and are updated all the time. This is a bare bones look at how search engines work to retrieve your search results. All search engines go by this basic process when conducting search processes, but because there are differences in search engines, there are bound to be different results depending on which engine you use.
  1. The searcher types a query into a search engine.
  2. Search engine software quickly sorts through literally millions of pages in its database to find matches to this query.
  3. The search engine's results are ranked in order of relevancy. 

Examples of search engines

1. Amazon Amazon.com is one of the best places on the Web to begin your book search. You can find out of print books here, rare books, used textbooks, and much, much more. You can also use Amazon to find upcoming book titles or take advantage of coupons specifically for Amazon.

2. ReadPrint ReadPrint is a free online library where you can find literally thousands of free books to read for free online, from classics to science fiction to Shakespeare. Download these books to your computer, your mobile device, or simply read them within your Web browser.

3. BookFinder.com BookFinder holds over 100 million new, used, rare, and out of print books within its substantial index. This is a good place to find books from independent publishers, as well as books that had limited printings.

4. Google Book Search Google Book Search allows you to search actual book text to find what interests you, and then gives you various places on the Web you can buy these books. Only text that is NOT copyrighted is searchable. Many free books are available here to read online as well as magazines, journals, and e-books.

5. Indie Store Finder Simply enter in your zip code to Indie Store Finder, and you'll be taken to a list of more than 1200 independent bookstores across the USA who are plugged into this unique book search engine. It's an easy way to find a local book store near you that might carry interesting books you won't be able to find anywhere else.
Sources; Search engines
 



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