Internet Search Techniques

Number of Terms / Relevancy or Boolean Searching / Default Search Features / More Precise Searching / Best Search Engines

How does the software handle my search terms?

To search an electronic index or a Web database, you must enter one or more search terms.  When you enter more than one search word, the search software will conduct its search based on its own rules for handling multiple-word searches.  Knowing how the software will perform its search is important for constructing a search statement that retrieves what you would like to find.

How many search terms should I enter?

An additional point you should consider before constructing a search is the amount of indexed terms in the database.  In library catalogs, most book records are quite brief, and you will need to match one of only a few terms.  For these systems, entering only one to perhaps three terms will be most useful (the odds of a record matching an entire string of words is very low).  If you are searching full-text databases or web pages, however, a one- or two-word search will retrieve many more results with a lower probability that they will all be pertinent.  For Web search engines, you should try to be as precise as possible, entering a number of words to refine your search statement and return a smaller number of very pertinent results.

Most search software uses variations on one of two techniques: 

Relevancy searching

Boolean searching

What are the default search features of most Web search engines?

Most search engines insert a Boolean OR (meaning any of the terms may occur in the result) if no operators are used, but rank entries that have all of the terms higher on their results lists than those that have just some of the terms.

How can I make a search engine search more precisely?

Many search tools have an "advanced" search option that can help you create a more precise search.

For most search engines, a plus sign + in front of a word means that that word must occur in any results.

for example, +new +mexico +pollution

Quotation marks can be placed around a phrase to retrieve those words as a phrase and not just as keywords appearing separately.

for example, "new mexico" retrieves that phrase and not entries that refer to "mexico" and anything "new"

Remember that more search words are usually a good idea in Web search engines, but not necessarily in library catalogs or periodical indexes.

What search engines should I use?

Try to become familiar with a couple of the best search engines (see our list) so that you get used to their particular search options.

Use a comprehensive search engine (like Google or AltaVista) when you are looking for everything you can find or if you are trying to find a Web page that isn't very well-known.

Use a selective search engine (like Yahoo) to search a more carefully selected group of Web pages.

Remember that each search engine lists sources not included in other programs, so try more than one or use a "meta-search engine" to search many at the same time.