Tips on combining keywords using Boolean operators.

1. COMBINED KEYWORD
SEARCHING
Jamie Dwyer
Visiting Assistant Information Services,
Research & Liaison Librarian
jamied@uic.edu
http://library.uic.edu

2. Synonyms & related terms
• Identify synonyms and related terms for your keywords.
• Not every word you use is used by researchers and/or
database indexes.
• Dietary patterns: diet, dietary habits, nutrition
• Lung cancer: lung neoplasms, cancer
• Sometimes you’ll be able to “zoom out” with your term
(lung cancer to cancer), other times you might be more
“narrow” or even identify a specific diet (paleo diet) or
drug/product/therapy name if that is relevant to your
search (Advil, Zumba, etc.).

3. Searching with synonyms- Option A
One way to incorporate synonyms into your search is to
search all the terms for a single concept at a time using OR,
then search all the terms for another concept, and combine
them together in an advanced search using AND.
• Looking at this in PubMed,
• Step 1: Search dietary patterns OR diet OR dietary habits
(431,713 results)
• Step 2: Search lung cancer OR lung neoplasms (264, 350 results)
• Step 3: On the Advanced Search page, combine the two searches
using AND (2,422 results). It will look like this:
(dietary patterns OR diet OR dietary habits) AND (lung cancer OR
lung neoplasms)

4. Searching with synonyms- Option B
• If you are comfortable with ANDs and ORs and using
parentheses, you can type out your search in the search box all
at once.
• Looking at this in PubMed, you would type and search:
(dietary patterns OR diet OR dietary habits) AND (lung cancer OR
lung neoplasms)
(2,422 results)
• You can see that the final search string is the same, it just
depends on your preference of searching one concept at a time
and combining or starting with everything. If you aren’t getting
the results you expect, consider searching with Option A to see
where your terms aren’t working well with the database.

5. Why does this work? Boolean
diet exercise
OR
Diet OR ExerciseDiet AND Exercise
AND
diet exercise
Diet NOT Exercise
NOT
diet exercise
• Searching with AND combines terms. It gives you results that satisfy both
search terms (only where the two overlap). Some databases use + for AND.
• Searching with OR “means more”! It gives you everything available for each
term, including when they overlap. Some databases use | for OR.
• Searching with NOT excludes an entire term, including any overlap between
terms. Some databases use – for NOT.

6. Boolean and synonyms
• Combine synonyms with OR:
(dietary patterns OR dietary habits OR diet)
• Combine concepts with AND:
(dietary patterns OR dietary habits OR diet) AND (lung
cancer OR lung neoplasms)

7. Combining concepts: FOIL
(exercise OR physical activity) AND (diet OR nutrition)
(exercise AND diet)
OR
(exercise AND nutrition)
OR
(physical activity AND diet)
OR
(physical activity AND nutrition)

8. Social media OR
Facebook OR
Internet
Quit smoking
OR smoking
cessation OR
substance use
High school/
college students
OR young adults
OR teenager(Social media OR Facebook OR Internet) AND (Quit
smoking OR smoking cessation OR substance use) AND
(High school students OR college students OR young
adults OR teenagers)

9. Need Help?
There’s a lot more information about library resources and
searching! You can get help the following ways:
• Ask a librarian your question via chat or email
• Drop by or call your UIC Library location
• Schedule an appointment with a librarian