Take care not to exclude an important aspect of your subject!
You can use the search operators AND, OR and NOT to combine search terms. These are the most commonly known and used operators.
The operators AND and NOT limit the number of results from a search. The operator OR does the opposite; it increases the number of results.
To see how this works, go to the website The Boolean machine. Move your cursor over the operators AND, OR and NOT to see how they determine your search.
You can also combine more than two search terms. Use brackets to indicate the priority. For example (Money OR inflation) AND banking.
Use keywords to:
In this way you can search for publications in which your subject is not part of the title. For example, if you search using the keywords “gas extraction” and ‘Groningen’, the results will include publications with titles such as ‘Gravity changes and natural gas extraction in Groningen’ and ‘Social impacts of earthquakes caused by gas extraction in the province of Groningen, the Netherlands’, publications that you would not have found if you searched using title words.
Use as many different keywords as possible that mean the same thing (e.g. environmental pollution, environmental contamination).
A thesaurus is the best place to find synonyms.
You can do separate searches for the terms you find, or you can combine them using OR.
The thesaurus indicates which terms are broader or more general (BT= Broader terms), which terms are narrower or more specific (NT= Narrower terms) and which related terms (RT) can be used to search the database.
Truncation (or wildcard symbols) can be used to broaden your search and include different spellings.
To do this, you shorten the search term to a word stem and, depending on which database you are using, you type either a question mark or asterisk after the word stem. The results will then include various endings and spellings.
If you search with environ*, the results will include publications with ‘environment’, ‘environmental’ and ‘environmentally’ in the text and/or title.
A question mark replaces a letter in a word; the results include British as well as American spellings.
For example, if you search with organi?ation, the results will include the British English spelling (organisation) as well as the American English spelling (organization).
If you search with labo?r, the results will include ‘labour’ as well as ‘labor’.
You can search for a specific expression or concept (e.g. “social media”).
To do this:
These actions will depend on the database you are using. Use the Help function for guidance.