Kinds of Search Engines and Directories :

Web Directories :

Web directories (also known as indexes, web indexes or catalogues) are broken down into categories and sub-categories and are good for broad searches of established sites. For example, if you are looking for information on the environment but not sure how to phrase a potential topic on holes in the ozone, you could try browsing through the Open Directory Project's categories. In the Open Directory Project's "Science" category, there is a subcategory of "Environment" that has over twenty subcategories listed. One of those subcategories is "Global Change" which includes the "Ozone Layer" category. The "Ozone Layer" category has with over twenty-five references, including a FAQ site. Those references can help you determine the key terms to use for a more focused search.

Search Engines :

Search engines ask for keywords or phrases and then search the Web for results. Some search engines look only through page titles and headers. Others look through documents, such as Google, which can search PDFs. Many search engines now include some directory categories as well (such as Yahoo).

Metasearch Engines :

These (such as Dogpile, Mamma, and Metacrawler) search other search engines and often search smaller, less well known search engines and specialized sites. These search engines are good for doing large, sweeping searches of what information is out there.


A few negatives are associated with metasearch engines. First, most metasearch engines will only let you search basic terms, so no Boolean operators or advanced search options. Second, many metasearch engines pull from pay-per-click advertisers, so the results you get may primary be paid advertising and not the most valid results on the web.


Other Pages in This Section :

Searching the World Wide Web : Overview : This section covers finding sources for your writing in the World Wide Web.

How the Internet and Search Engines Work : The Internet is made up of a vast amount of computers networked throughout the world via data lines or wireless routers.

Searching with a Search Engine : A search engine is a device that sends out inquiries to sites on the web and catalogs any web site it encounters, without evaluating it.

Searching with a Web Directory : There are two main types of directories.

Search Engine and Web Directory List : The following is a list of some of the most powerful search and metasearch engines and most comprehensive web directories.

Resources to Search the Invisible Web : The Invisible Web includes many types of online resources that normally cannot be found using regular search engines.

Other Useful Sites for Finding Information : Other Useful Sites for Finding Information include all.

Other Strategies for Web Searching : Don't limit your Internet searching to using search engines. Be creative and think about which Internet sites might have the information you are looking for.