They connect your search terms to either narrow or broaden your results.
The three main Boolean operators are AND, OR, & NOT.
AND = reduces the number of results
ex: cats AND felines will only pull records that have both "cats" and "felines" mentioned in them.
AND is implied in many databases if you list your search terms
OR = increases the number of results.
ex: cats OR felines will pull records that have either the word "cats" or the word "felines," which will increase the number of possibilities.
NOT = reduces the number of results
ex: cats NOT felines will pull records only mentioning "cats" and will exclude any record mentioning "felines."
Databases usually give "AND" precedence and will join those terms first.
Enclose the words you want joined with "OR" in parentheses.
ex: dogs AND (cats OR felines)
Keyword vs. Subject Headings
The type of searching with which most people are familiar
Use words or phrases that describe your topic
Enclose phrases in quotation marks to make sure the database searches that exact phrase, instead of the individual words of the phrase.
ex: To search for the Animal Welfare Act, which was signed into law in 1966, you would need to search "Animal Welfare Act" in quotations. Otherwise, the database will pull results where the individual words are in various places in the record, meaning the results may actually have nothing to do with the law you are seeking.
Use Boolean operators if necessary to combine words and phrases, or use the Advanced Search options.
Subject Headings/Controlled Vocabulary
Subject headings are used to help you find related information more efficiently and areespecially helpful in medical databases. They are the way a database or catalog defines a topic, which means you can find more relevant results quicker than with keyword searching.
To find subject headings for your topic:
Look to see if the database has an online thesaurus for subjects that match your topic. This could be labeled as "Thesaurus" or as "Subject Terms" or "Subject Headings" -- obviously it can vary, depending on the database. You might even need to check the Help Screen in the database.
Once in the thesaurus, type in your keyword(s) and the database will give you the correct term(s) to use.
OR you can:
Start with a keyword search, using those words or phrases that describe your topic.
Browse the results and choose a few that are relevant.
Click into the records of the articles that interest you.
Scroll down to look at the Subject Field and note the terms that are listed.
Redo your search, using those terms.
Truncation and Wildcards
To be used when searching with keywords.
Truncation and wildcard symbols can vary by database.
Check the help screens to see which symbols are used in a specific database.
Common symbols are * or !
Use truncation or a wildcard symbol when:
Root words have multiple endings. Example: sun = suns, sunshine, sunny, sunlight
Search for = sun*
Words are spelled differently, but mean the same thing. Example: color, colour
Search for = colo*r
Filtering the Database
Limiting the Number of Databases
Camden-Carroll Library has 171 databases. You can find the most relevant databases for your search by narrowing down your options.
On the Databases A-Z list, click on "All Subjects." Scroll down to find your topic, in this case, it would be "Imaging Sciences."
Click on "Imaging Sciences" and you will see there are 16 relevant databases.
If you would like to further reduce your number of options, click on "All database types," and you will see various options.
For instance, if you want to limit results to "Journal Literature," you will notice there are 11 relevant databases.
So, there are 11 available databases that match "Imaging Sciences" and "Journal Literature."
Filtering Within the Database
Once you have chosen a database, you can filter within that database to make your search easier.
You can do an "Advanced Search" option and "Select a Field" within the database.
And/or you can scroll down the page and apply various limiters like "peer reviewed," "first author is a nurse" (in CINAHL), "full text," and so on.