Combining Concepts
Visual map of concepts using a Venn diagram
Conceptualizing a search strategy to research: Randomized controlled trials (RCTs) studying social skill development in children with Attention Deficit Hyperactivity Disorder (ADHD). Learn more about developing a research question.

By using Boolean operators, the database returns results for articles that meet all four components of the search (i.e., the center of the Venn diagram where all four concepts overlap).
Adding synonyms for your concepts

Copy-and-paste version of above image
(social skills OR interpersonal skills OR role play* OR social competence OR social behavior OR social behaviour)
AND
(Attention deficit disorder OR attention hyperactivity disorder OR adhd OR ad hd OR hyperactiv* OR hyperkine*)
AND
(child OR children OR pediatric OR boy OR boys OR girl OR girls OR preschool* OR adolescen*)
AND
(randomized controlled trial OR randomized clinical trial OR randomized trial OR randomised trial)
In many databases, the asterisk is a wildcard; it can be considered a 'fill in the blank' option for the database. Wildcards can cause issues, especially if used incorrectly because not all databases understand the asterisk the same. Learn more about using wildcards in different databases.
Note the parentheses around synonymous or conceptually similar terms.
Revising your search
Searching is iterative and you should not expect to get it right on the first try!
Tracking your search
After trying your search, in a document or spreadsheet, record the following information so you can reproduce the search later or improve it another day:
- Search string (the keywords including the parenthesis and Boolean operators)
- Which interface you used to search which database you searched (e.g. PubMed: MEDLINE, indicating PubMed is the interface and MEDLINE is the database)
- Date you ran the search
- Number of results
Evaluate your results
- Do you need to add keywords?
- E.g., plural versions of your terms or alternate endings like large capacity magazines or nursing for terms like nurse and nurses
- Would truncation and a wildcard help -- note when a word ends early and an asterisk is inserted, that is instructing PubMed to end complete the word with other options; e.g., adolescen* in the search above will search for adolescence and adolescent and adolescents.
- Do you need to remove keywords?
- E.g. some of our terms have a second meaning that we are not interested in so we may need to use quoted phrases to find "large capacity magazine" in the title, abstract, or keywords of the articles in PubMed
- Are there any typos in your search terms?
- Are your ORs and ANDs and parentheses in the right place?
- Check your parentheses with Balance Braces
- Try changing the font and/or font size of your search to better proofread your Boolean operators
- Are there too many results to reasonably go through?
- Modify keywords
- Add another concept like: AND (harm reduction OR injury OR injuries)
- Try a filter (found on the left side of the PubMed results page)
- Too few results? Zero results?!
- Are all of your concepts actually required? If not, try adding them with an OR rather than an AND Boolean operator
- Check Boolean Operators; are you using an AND when an OR is needed? E.g., child AND children OR kid – these are all conceptually similar so we should use ORs between each term
- Could research from another area apply to your population? E.g. you may not find anything for King County but you likely will for Washington State or the U.S.