Search terms and Boolean search strings: a simple guide
With the new university term starting soon, we’ve put together a simple guide to finding the right search terms for your next assignment. Whether it’s for your final-year dissertation or your first-year essay, the same approach applies.
Rather than typing your whole assignment question into Google Scholar, your university library search, or relevant databases, breaking it down into key concepts will help you carry out a more focused and effective academic search. The process of developing your search terms and creating a search string can also be a key element of methodology sections within larger assignments and some dissertations. So, getting this right can help demonstrate that your research process is thorough and clearly explained.
1. Identify your key concepts
Identifying the key terms from your assignment title or question is the first step. Usually, this will be two or three main concepts that sit at the centre of your assignment.
It’s worth remembering that key terms aren't necessarily individual words; they can also be short phrases.
Let’s take a look at an example question:
What is the impact of music therapy on nursing home residents with dementia?
From this question, we can identify three main concepts:
Music therapy
Nursing home residents
Dementia
You might notice that we haven't included every word from the assignment question. For example, “what is the impact of” helps tell us what the assignment is asking us to investigate, but it isn't necessarily something we need to include in our search.
2. Connect your key concepts using AND
Once you've identified your key concepts, you can begin to turn them into a search.
Because all three concepts are important to our assignment question, we can connect them using the Boolean operator AND:
"music therapy" AND "nursing home residents" AND "dementia"
Using AND tells the database or search engine that we want our results to include each of these different concepts. This helps to make our search more focused and relevant to the assignment question.
This gives us a basic Boolean search string, which we can now develop further.
3. Think of alternative search terms
The next step is to expand each of your key concepts by thinking of synonyms and alternative ways of describing them.
This is important because different authors may use different terminology to describe the same or similar ideas. If we only search using one term, we risk missing useful research that uses different language. For our example question, we could expand each of our key concepts with the following alternative search terms:
Music therapy
music intervention
music-based intervention
musical activities
Nursing home residents
care home residents
residential care
nursing homes
Dementia
Alzheimer’s disease
cognitive impairment
Not all alternative search terms will mean exactly the same thing. For example, cognitive impairment is broader than dementia. Broader or related terms can sometimes help you discover additional literature, but they may also produce results that aren't directly relevant to your question.
Because of this, we can't assume that every search result will be relevant. We still need to assess each result, starting with its title and abstract, before deciding whether it is useful for our assignment.
4. Use OR to combine alternative terms
We can now combine the alternative terms within each concept using OR.
For example:
"music therapy" OR "music intervention" OR "music-based intervention"
Using OR broadens the search because it tells the database that results can contain any of these alternative terms.
So, as a general rule:
OR = connects alternatives within the same concept
AND = connects different concepts together
5. Use quotation marks for phrases
You may have noticed that we have placed quotation marks around search terms containing more than one word, such as "music therapy" and "nursing home".
Quotation marks can be used to search for words together as an exact phrase, rather than searching for each word separately. This can help to make your search more focused by retrieving results where those words appear together.
For example, searching for "music therapy" tells the database to look for that phrase, rather than searching separately for the words music and therapy.
6. Build your complete Boolean search string
We can now bring everything together into a more developed Boolean search string:
("music therapy" OR "music intervention" OR "music-based intervention") AND ("nursing home" OR "care home" OR "residential care") AND ("dementia" OR "Alzheimer's disease")
This search string is now ready to try in your university library search, relevant databases, or Google Scholar.
Need some help with your research?
Finding the right search terms can make academic research feel much more manageable. If you're struggling to develop a search strategy for your own assignment, Aster's One-to-One Tutorials can help you identify your key concepts, develop effective search terms, and find relevant academic literature for your topic.
