Google searches often yield too much information to be useful and can quickly overwhelm the searcher with too much information. Google’s advanced search options (http://www.google.com/advanced_search) help sift useful information from large search results.
SEARCHING GOOGLE ADVANCED SEARCH
While many advanced search techniques, such as Boolean searching, can be used on the default search page, most options are more easily used from the advanced search screen. To get to the advanced search page, begin typing a search in Google then click on the Advanced Search link.
Google’s advanced search screen provides search fields, many of which serve the same function as Boolean search options that help narrow search results. The advanced Google search options used individually or in combination can greatly fine-tune your search, such as searching by domain (.edu, .gov, .mil, etc.) which significantly decreases large search results while focusing those results on academic and other authoritative resources. Other useful advanced options include:
Find Web Pages That Have...
All These Words: The search results will include every word that you entered into the search. Normally Google will provide results from pages that do not include a search term if it has other evidence that indicates that the page is relevant. While this practice is often useful, it is not always correct. If search results must have every word of your search, using this option will prevent Google from excluding any of your search terms.
This Exact Wording Or Phrase: This option replicates the use of quotation marks to indicate a phrase or the plus-sign (+) to indicate that a word should be used exactly as it is typed (no truncation, synonyms, or corrections).
One Or More Of These Words: This alternative replicates the Boolean OR search. Includes pages that have any but not necessarily all of the search terms.
Don’t Show Pages That Have… Any Of These Unwanted Words: This option replicates the Boolean AND NOT or the use of the minus-sign (-). It excludes search results with the indicated term.
Language: Users can limit search results to those in a desired language.
File Type: This is especially useful when looking for a specific document. It can be used to limit results to those in a particular file format such as .pdf.
Search Within A Site Or Domain: This is very useful for large search results, or to search within a page that does not have a search option or poor search engine. Limiting searches by domain (.edu, .mil, .gov, etc.) can reduce a very large search result to a more manageable size. You can search by multiple domains by listing more than one in the box (.edu, .mil, .gov). However, for some reason Google deletes spaces between multiple domains (.edu,.mil,.gov). After clicking search you must insert a space after each comma in the search box (.edu, .mil, .gov). If results are still too large, search by domains individually.
Date, Usage Rights, Numeric Range & More: The more useful options in this section include:
Date: (how recent the page is): Limit your search to pages that were created within a desired date range.
Keywords Present: Limit your search to pages where the keywords show up in the title, text, URL or links of a page. Searchers often have good results when they search for keywords in title.
Region: Limit your search to pages that were created in a desired region or country.
NOTE: The options described above can help users limit search results to those that should be the most useful while avoiding information overload.