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Kirk Library Website and Resources Introduction (No Quiz)

Selecting Search Terms - Keywords and Booleans

What are Search Terms?

Search terms, or search strings, are all of the words that are entered into a search box in a search engine or database. We might be used to typing an entire sentence or question into the search box for Google, Safari or Edge search engines. This way of communicating is called natural language, but many databases have a hard time with natural language. Databases can provide better results through the use of keywords and Boolean Operators/Modifiers.

What are keywords?

You may be accustomed to researching topics by typing questions into a Google search bar. When searching Library Databases, brainstorm words that are related to your topic and then use the most meaningful nouns, or keywords, as your search terms. Leave out adjectives, adverbs, prepositions and, in most cases, verbs. Sometimes using an online thesaurus, a Wikipedia article, or Googling your topic can help you generate keyword ideas. A great start can be pulling out the main ideas stated in your research question or preliminary thesis statement.

EXAMPLE: If your research question is: "Is coffee bad for you?," some keywords to try in a database might be: "caffeine AND health AND risks". (More on the "AND" in the Boolean Operators and Modifiers section below.) 

Librarians can help you find good keywords! Use our Chat with a librarian 24/7 for help!.

The following closed captioned video offers advice on starting your list of keywords.

How to choose Keywords by McMasters University Libraries.  A transcript is available on YouTube.

What are sustainable alternatives to dams to control climate change related flooding?

The bolded words are the "initial keywords" I identified from the research topic. I then brainstormed more keywords for each of those initial keywords:

"Sustainable alternatives"

  • "environmental solutions"
  • "environmentally friendly"
  • "viable alternatives"

dam*

  • dike* (dike OR dyke) d?ke
  • levee*
  • breakwater
  • seawall
  • embankment
  • "flood control structure*"

"Climate change"

  • "Global Warming"
  • "Climate crisis"
  • "environmental crisis"

Flooding

  • "Flood control"
  • "Sea-level" AND (rise OR increase), Sea-level rise, SLR
  • "storm surge"
  • "storm tide"
  • "flood plain"
  • "coastal flood*"
  • "river flood*" 
  • "fluvial flood*"

Boolean Operators and Modifiers

Many library databases require a special set of conventions. In this case, we are exploring Boolean operators (AND, OR, NOT), and the Boolean modifiers, truncation symbols, nesting, and quotes. Databases and search engines apply these rules differently, so check the HELP files in the database you are using to find out more.

This video explains the Boolean Operators, AND, OR, NOT, and how to use them

How Library Stuff Works: Boolean Operators (AND OR NOT) by McMasters Libraries.  Video is closed captioned and a transcript is available on YouTube.

In addition to AND, OR, NOT, there are additional symbols, Boolean Modifiers, that can help improve your searches. As we will see in the video below, these Boolean modifiers, (), "", *, ?, can help refine your search even more.

How Library Stuff Works: Boolean Modifiers by McMasters Libraries.  Video is Closed Captioned and a transcript is available on YouTube.

  • "sustainable alternatives" AND d?ke
  • ("climate change" OR "global warming") AND "Sea level rise"
  • (breakwater OR "sea wall" OR seawall) AND ("storm tide" OR "storm surge")

Tip: Sometimes it is better to break your search topic into smaller chunks. Searching for altenatives, water control devices, climate change, and flood waters may prove to be too many ideas together, so divide it up into more manageable segments.

 

Boolean Operators and Modifiers Summary

AND Use AND to retrieve both search terms

OR Use OR to retrieve either search term(s)

NOT Use NOT to exclude search term(s)

" " Use " " to keep the order of words or phrases intact

( ) Use ( ) to organize the order of relationships in your search

*  Use * to the end of a term to search all ending of the root word, e.g. govern* retrieves government, governmental, govern, governs, governor 

Use ? to find alternate spellings, e.g. wom?n retrieves woman or women. Also find differences between British and American spellings, e.g. behav?r retrieves behavior or behaviour 

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