Step 1: Eliminate the "filler" words in your research topic that will not help you retrieve relevant articles. What you have left will be the keywords you'll search:
Step 2: Think about whether your main concepts have any synonyms or related terms that you should search (you want to try to predict what other terms authors might have used for your topic.)
Note: If you can't think of any synonyms, that's okay -- some concepts don't have any relevant synonyms or related terms. To help you keep track of the keywords and synonyms, build a keyword table:
* An asterisk at the end of a word tells the database to find any possible ending to that word, so dens* will find dense, density, or densities.
Step 3: Combine your keywords using connectors like like "AND" and "OR" when you enter your search into a database -- the keyword table can help you understand how to connect your keywords.
Use AND, OR, or NOT to connect concepts together to broaden or narrow your search, or to eliminate concepts you don't want searched. These three words (AND, OR, and NOT) are called Boolean operators.
|Narrows a search -- articles retrieved must have both terms
|Broadens a search -- articles retrived may have either term
|Narrows a search by excluding concepts you don't want searched
|example: bone AND structure
|example: soda OR "soft drink"
|example: Coke NOT Pepsi
Make sure to capitalize AND, OR, and NOT -- this tells the database that the word is a "search operator" and not a keyword that it should be searching for.
You can use quotation marks to force the database to find an exact phrase.
Quotation marks can help you narrow down your search:
This search will exclude articles where search terms appear individually, such as "soft pillow" or "sugary drinks."
But be careful that you don't inadvertently narrow your search too far:
soda AND "bone density"
This search would miss articles where authors use the phrases "bone mineral density" or "bone densities."
Experiment with your searches to see which combination(s) of your keywords get the most useful results!
In many databases, an asterisk (*) tells the database to search for different word endings so that you don't have to enter and search all variations of a word.
Instead of searching (simulate OR simulates OR simulation) just search simulat* --it's easier!
Getting too many results?
To narrow searches and get fewer results:
Getting zero results (or a very small number)?
To broaden searches and get more results:
*Still getting zero results? Try another database or Ask Us! We're here to help.
*If you've done a thorough literature search using a variety of different search queries in all appropriate databases and you still get zero results, celebrate! You've found a gap in the literature. Remember: gaps in the literature = opportunities for research = jobs!
For each new database you search, look to see how your results are being sorted.
Databases usually default to either:
*If you have too many results, try sorting by relevance to see if some good articles rise to the top
But remember: when you sort by relevance you run the risk of older articles rising to the top of your results list.
Some databases, such as Web of Knowledge and Google Scholar, provide metrics showing the number of times an article has been cited by other articles. Looking at the articles that cite an article is a way of seeing how the research has progressed over time.
In Web of Knowledge, you can sort your results by times cited- highest to lowest to see which articles have been cited the most (the most highly-cited articles might be particularly important if lots of other authors have cited them).
*Citation metrics can be confusing -- if you'd like more information, remember you can always contact a librarian.
Some databases have a controlled list of subject terms that you can use to build your search -- this list is usually called a thesaurus.
PubMed, an important biomedical database, has a thesaurus called MeSH (which stands for Medical Subject Headings). PubMed is such a complex database that it is usually more productive to build searches by selecting terms from MeSH. Below is an illustration of a table you could use to keep track of your search terms and the related thesaurus terms from each database:
If you'd like to learn about constructing a search using a database thesaurus, remember you can always contact a librarian.
Some databases allow you to manipulate and analyze a result set in a number of ways.
If you'd like more information, remember you can always contact a librarian.
Most databases have a link to a help page that will show you what search features are supported.
For example, in Web of Science, you can: