Search Engines

Search engines are automated systems that record and index text (keywords) from each webpage they scan. The search engine indexing software typically notes the links in a page, checks to see if the links can be tracked to unindexed pages, and moves on to index these pages and continue this process automatically. Because search engines are automated, they can index billions of web pages (as www.google.com does ), as compared with manually indexed directories, which rarely reach a million indexed pages.

While search engines provide the most comprehensive indexing of the Web, the keyword searching they offer often makes it difficult to retrieve information.

Another weakness is that many search engines only index the title, URL, perhaps any metadata coded by the web page developer, and a set number of words from a document. This limit on the number of words indexed per page often results in long documents being incompletely indexed.

-DD