To use databases efficiently there are several search techniques you can use to improve the precision of your search results. These include: phrase search, wildcards, and Boolean logic. Learn how to use these handy techniques to become more successful in your quest for information by watching the video Searching databases (4:54).
Also have a look at the module Search techniques - from snowball to cited reference search to learn more about different search methods.
Phrase search is one of the most used and most effective search techniques. When applied, it treats the combination of separate search terms as one phrase. A phrase search is executed by putting the search terms between quotation marks, for example: “George Bush”. The advantage is that the search results are usually more specific. However, you run the risk of accidentally excluding relevant results. For example, when you search on “George Bush”, all results referring to “George W. Bush” are excluded from the results list. Phrase search works best when applied to phrases which are fixed, such as titles of publications or very specific terminology.
An example of phrase search in Google Scholar:
Wildcards are useful for finding variant characters within a word (masking) and for finding words with different endings (truncation). This is useful when you have a keyword that could be written in different ways and you are not sure of the exact spelling, or you wish to leave it open.
Symbols used as wildcards may differ between databases. If using a database for the first time, check the search tips or help section to find out which wildcards are in use and how they work.
Wildcards in sEURch:
# replaces one character in the middle (wildcard) or at the end of a word (truncation).
There have to be at least three characters before the #
wom#n finds woman and women
recreat# finds recreate
recreat## finds recreates, recreated
recreat### finds recreation, recreating etc.
? replaces multiple characters in the middle of a word (wildcard) or at the end of a word (truncation).
There have to be at least three characters before the ?
col?r finds color, collar, collector, collier, colonizer, colour etc.
compet? finds compete, competing, competent, competence, competition, competitively, competitiveness, competitors, competitive, etc
Use ?n in combination with a number, 1-9, to specify the number of characters you want to find.
colo?1r finds color, colour
re?4tion finds recreation, refraction, relaxation, revolution etc.
compet?3 finds compete, compete?, compete! , competing, competent, etc.
* replaces all remaining characters in a word (truncation)
There have to be at least three characters before the *
compet* finds compete, competing, competent, competence, competition, competitively, competitiveness, competitors, competitive, etc
Use the boolean operators AND, OR and NOT between keywords to search more precisely for what you want. AND combines terms so that each search result contains all of your terms. OR will look for any of your terms, so that each search result contains at least one of your terms. Put NOT before a search term you want to exclude from your search.
See also the module: Build your search profile on how to combine search terms in a search profile and how to establish relationships between terms.
An example of boolean search in Communication Source (an EBSCO database):
In the exercise Broaden or Narrow you can test what happens with the number of results when you use Boolean logic.