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Subject Directories
A subject directory provides lists of Web sites that have been
organized by human beings. If your topic is included, you can
often find good starting points by using a subject directory.
Subject directories usually offer you two search approaches -- you can
select a general topical area, and then narrow down; or, you can begin
with a keyword search. Subject directories cover only a small fraction
of Internet resources. Examples:
Yahoo! (best known overall; commercial sites comprise about
75% of its database), Librarians' Index to the Internet (selection
of high quality resources; good for academic topics).
Search Engines
Humans organize and catalog subject directories. Current estimates are that
there are about 7-8 million new Internet resources per day.
Subject directories can cover only a small portion of what's available.
Search engines, by contrast, use computer programs called spiders or
robots to crawl the Web and bring back information about publicly accessible
resources. When you use a search engine, you type keywords into a search
box. The search engine searches its database and gives you
back a results list that has links to Internet resources that have the
terms. To retrieve results focused on your topic, you must formulate
your search statement in ways required by the specific search engine
you are using. Examples: AltaVista; Google, Northern
Light.
Meta-Search Tools
There are a number of tools that broadcast a search to more than
one search engine. It is important to note, however, that although
meta-searching has the advantage of simplifying queries, you are not able
to take full advantage of specific search options offered by each specific
search engine. Best to use when you have a very specific or unusual search
term to gauge the extent of Web resources. Examples: Dogpile; Metacrawler
Summary
| Subject directories |
Made by humans; cover only part of the Internet |
Use in initial searching or when you want general information. |
| Search engines |
Made by computer programs; cover large portions of the Internet |
Use for specific, focused searching. |
| Meta-search tools |
Broadcast search to a number of search engines; search precision is
sacrificed. Northern Light is not covered by any meta-search tool. |
Use if you have a very specific or unusual search term, or just to
gauge what's out there. |
To get to the library's list of search engines, meta-search tools, and
subject directories:
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Be on the Cabrillo College Library homepage http://libwww.cabrillo.cc.ca.us
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Click on Search the Internet
T. N. Smalley last rev. 11/01 |