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Search Strategies

When conducting research, the key to successful searching is not in the quantity of search results, but rather how relevant and appropriate they are to the topic. Whether you are searching the web with a search engine such as Google, or searching a research resource like Summon, the library catalogue (QCAT) or another library database there are some common search techniques that can be employed to improve the efficiency of the search results.

In this module, we will look at strategies for constructing an effective search in a library database. You will learn to create an effective search strategy using:

  • relevant keywords
  • synonyms (equitable OR fair)
  • Boolean operators (and/or/not)
  • parentheses
  • phrases ("common law")
  • truncation (politic? = political, politics)

Choosing Relevant Search Terms

Example of a possible research question: 

Using the example of Guatemala, analyse the appropriate role for the Canadian state in regulating the behaviour of Canadian mining companies in developing countries.

Break down the topic into keywords and phrases:

Using the example of Guatemala, analyse the appropriate role for the Canadian state in regulating the behaviour of Canadian mining companies in developing countries.

Now, think about whether there are other terms that could also be used to describe the topic, including synonyms, related terms, or words and phrases that have similar meaning.

Note: Most databases use American spelling, so, when applicable, you should search for both versions of a word
(e.g. labour, labor).

Connecting Keywords

Once you have identified the keywords and phrases that describe your topic, the next step is to connect them in a logical way that the database will understand - this is accomplished with the use of Boolean operators:
AND, OR, NOT. Databases and many search engines including Google make use of Boolean operators. Understanding how databases interpret your keywords will allow you to execute more specific searches, thereby saving you time while retrieving more relevant results. (A database's help pages will indicate how to construct Boolean searches and which wild-cards the database supports.)

Used for
What it Does


when you want to find material containing two or more concepts

using AND between keywords means that both terms must appear somewhere in the record

narrows your search


Guatemala and mining



when you want to find material containing either or any of the keywords

use OR to combine synonyms and related terms

broadens your search


Guatemala or "Central America"


use NOT to exclude a concept or word from the search

use NOT sparingly, if at all, because you could end up excluding useful search results (e.g. articles or books that discuss both concepts)

narrows your search




Guatemala not Mexico


Nested Searching

Whenever you have more than one Boolean operator, such as AND and OR, in a search statement, it is necessary to separate them with parentheses. This is known as a "nested searching." Here's an example:

("third world countries" OR "developing countries"

Nested searching tells the database the proper order in which to search for the keywords. Operations enclosed in parentheses are performed first followed by the operators outside the parentheses.


Rules about phrase searching vary from database to database. Some databases require them (without them an AND would be assumed, or worse, the database wouldn't be able to interpret your search), others supply them for you. The Help Screen of the database you are searching will indicate whether or not quotation marks are required.

"third world countries"
"developing countries"


In many library databases (including QCAT, the Library Catalogue) you can also use a truncation symbol to broaden a search. Truncation is like a shortcut. Placed at the end of the root of a word (or word stem), a truncation symbol tells the database to search for variant endings of the word, including plurals and singulars.

Truncation symbols vary between databases. In QCAT, the truncation symbol is a question mark (?), in the article database CBCA (and many other databases), the symbol is an asterisk (*).

An example of a truncated search in QCAT would be:


An example of a truncated search in an article database such as CBCA would be:


The database would interpret the search as teen, teens, teenagers, etc.

Be careful when using truncation as it can produce unintended results. For example, a search for cult* retrieves cult, cults, cultivated, culture, cultures, etc. Only truncate back as far as it would be useful and still on topic.

In the next module, we will apply these search techniques to searching QCAT for books and will briefly look at searching for books in Summon.