Web Directories look like search engines, and many of them include a search engine component. But Web directories are different from search engines because they are collections of data about Web sites that are categorized by people and not computer programs.
The most famous web directory is Yahoo! <http://www.yahoo.com>, which was started in 1994 by two graduate students at Stanford, David Filo and Jerry Yang. But there are many other Web directory sites, including the following:
In a sense, Web directories are more like library databases: they are organized by people into logical categories, and the organizers of Web directories make some choices as to what they will and won’t include in their directories and about how they will categorize different items. However, each search engine makes up its own system for categorizing data; there is no “standardized” system of subjects like there is with the Library of Congress system. This means that while Web directories are “more organized” than what you might find with a search engine, they are probably “less organized” than what you might find in the library with a book or periodical database.
Web directory searches will often return higher quality Web sites because what is and isn’t included in these directories is decided by people and not computer software. Further, some of these Web directories, like the “Librarian’s Index to the Internet,” are quite a bit more selective and specialized. Conversely, Web directories don’t usually give you the “quantity” of information that you are likely to receive from search engines or metasearch engines.
In general, the best advice for working with Web directories is very similar to the best advice for working with search engines: be sure to read the instructions on conducting advance searches, use more than one Web directory, and use synonyms for your key terms. Use search engines, metasearch engines, and Web directories in conjunction with each other: the “computer software” based searches you do with search and metasearch engines can help you refine the searches you conduct with the help of Web directories.