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NOTEBOOK - NOTE #A17: SEARCH ENGINES &
DIRECTORIES
Using search engines and directories can
be a bit overwhelming because of the volume of hits which are
returned by the search terms used by most inexperienced or casual
information searchers.
There is an art and a science to
searching any database from library catalog, through periodical
index on to a file on a World Wide Web server. Library catalogs and
periodical indexes/databases usually follow particular standards and
rules which makes it possible to search particular fields within the
record or full-text. This helps control the number of records
returned and is quite specific and likely to be what is being
sought.
General basic searches on World
Wide Web engines and directories are likely to return irrelevant
hits because most have been indexed on all words in the document and
not on specific subjects. Some engines have organized and
indexed their catalogs of pages so that desired information will
appear more often than do other engines. The algorithms for
searching and indexing are improving in general but still bring in
huge numbers of hits.
When doing general searches it is very
important to select search terms that are as specific as possible
and even unique to the topic you are hunting. When faced with
a huge number of hits, go back and add one or more search terms and
browse this list of hits for specialist words which will be useful
search terms and repeat the process.
Some search engines assume the 'and'
between terms but some will search for adjacent terms so it is wise
to look at the online instructions from the search engine company or
search your terms with and without the 'and'. Search engines
generally will not search 'stop words' such as: a, an, the, it, for,
as ...
Many search engines have Advanced
Search options which allow searchers to exert more control on
the number and type of files returned. Some will search exact
phrases, all of the words, or any of the words. Some will allow
searchers to designate files to exclude because of the presence of
particular words. In the preferences or options choices on some
engines, it is possible to select the number of hits returned per
page, whether or not to open pages in new browser windows and even
to select some content filters. The number of advanced features
continues to grow so it is worth checking on advanced search
possibilities when needing to see if desired information is freely
available on the WWW.
Some services offer directories or
subject categories on their main pages. These are collections
of websites grouped with the possibility to use an algorithm just to
search among the pages pre-grouped in the category. Other
websites are subject specific, having cataloged only websites
pertinent to a topic such as law or human rights or economics. These
also help searchers control the number of hits returned.
If looking for images or graphics, use
one of the engine/directories which specialize in these and do not
return any textual information.
The Busse Library WWW Search Tools
page is an index of selected engines and directories which have been
found to be useful. Tips on evaluating information sources including
webpages are found on MMC Notebook Note
#B1. |