Dr. Esi Thompson

Most library databases use Boolean operators (AND, OR, and NOT). 

Use them to narrow or broaden search results.

• AND for records that include both terms (narrows search)
• OR for records that include either term (broadens search)
• NOT to exclude irrelevant concepts (narrows search)

Example:

Iran AND China AND (energy OR petroleum OR oil) 

Adapted from SAIS Library, Johns Hopkins Univ. "Database Search Tips" Guide

Using AND:

• narrow results
• ALL terms must be in each search result

Note: in most, but not all, databases, the AND is implied. For example, Google automatically puts an AND in between search terms.

Example:  renewable energy AND China

Using OR:

• connect similar concepts (synonyms)
• broaden results (ANY of the terms can be in the search results.)

Example:  renewable energy OR solar OR wind

Using NOT:

• exclude words from search
• narrow the search

Example:  peacekeeping NOT United Nations

Adapted from SAIS Library, Johns Hopkins Univ. "Database Search Tips" Guide

Overview of database search tips.
From Yavapai College Library. 

If your initial searches bring back no or few results, don't give up! Don't despair! Reassess your search strategy.

Possible Reasons

Choice of Search terms

Choosing the right search terms is key.

• Experiment with related terms.
• In databases Subject Terms can help you identify keywords.
• Use OR to search for multiple related terms simultaneously. (e.g., policy OR law)

Too Many Search Terms

Database can be picky about search terms. Be selective.

• Begin with one of two search terms that best represent your topic. Then add other terms as needed.
• Avoid long phrases and empty words like “the” and “how.”

Too Many Limiters

If you limited the search (e.g., by date or search field) remove limiters and reassess.

Narrow Topic

Highly specific topics may be too narrow for finding results. Try a broader related topic first.
Example: 

• Narrow search: Bloomington Indiana AND environmental policy
• Broader search: United States AND state government AND environmental policy

Database Choice

Different databases focus on different topics, so it could be that your search terms are well calibrated, but you're looking in the wrong place. View Resources by Subject or Ask a Librarian.

Add additional keywords.

•  In databases Subject Terms can help you identify more narrow topics and keywords.
• Add AND between your keywords

Choose more narrow search terms

Broad topics tend to have a broad range of people writing about it. If you're finding too many articles related to your topic, consider narrowing down your focus and search for that narrower subtopic.  

Example:

• Broader term: law
• Narrower term: "environmental law"

Use limiters

You can limit your searching in two ways: by only searching specific fields or by limiting results by different facets, often found on the left hand side of the search results.

 Search fields like

• title
• abstract
• author

Or use limiters on the side to refine by

• publication date
• format type
• subject

In OneSearch, you can see options under Refine Search.

Search for a short phrase with quotation marks. 

Using quotation marks searches for that phrase as a single unit rather than two separate terms.  

Examples: 

• "environmental law"
• "environmental justice"

Records in library databases are made of "fields." Fields can help narrow your search.

Examples:

• author
• title
• journal title
• abstract
• publisher
• date/year of publication
• subject/descriptor
• all text (searches the full text, if available)

Improving Search Results with Fields

• Most databases automatically search by keyword (looking for the term anywhere in the record).

• Limit the field for a search term to narrow the results. 

• Fields are usually in drop down boxes.

• If the database has a single search box with no drop-down menu, look for an "Advanced Search" option.

Adapted from SAIS Library, Johns Hopkins Univ. "Database Search Tips" Guide

Use quotation marks or parentheses around search words to search for a phrase. 
(Otherwise most databases will find records that include both terms, but not necessary the terms as a phrase.)

Examples: 

"middle east"
"united nations peacekeeping forces"
"civil society"

Adapted from SAIS Library, Johns Hopkins Univ. "Database Search Tips" Guide

Truncation broadens your search to include variant word endings and spellings. Enter the root of a word and then the truncation symbol.

Examples:

elect* = election, electoral, elections
econ* = economy, economic, economics, econometric, economique
politi* = politics, political, politician, politique, politische

The most commonly used truncation symbol is an asterisk (*)
A exception is LexisNexis Academic, which uses an exclamation mark (!).

Adapted from SAIS Library, Johns Hopkins Univ. "Database Search Tips" Guide

Nesting is the use of parenthesis to put search words into sets. Use nesting with AND, OR, or NOT, 

Example: 
success AND (education OR employment) 

(records will contain the word success, AND either the word education OR the word employment)

Nesting is often used when search terms have similar meanings:

Example: 
education AND (employment OR jobs)