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Composing a Search: Synonyms

Interactive Guide to demonstrate how to compose a search and test it on a sample of library databases.

Synonyms and Related Concepts

Authors may use a variety of terms to describe the same thing.  For instance, one may refer to a car, another to a motor vehicle and another to an automobile.  Yet they are all talking about the same thing.

Computers will only search for the term you enter.  If you search for car you will not find articles about motor vehicles or automobiles.

For each of your key terms, limiting terms and excluding terms you need to identify any synonyms or related terms.

Tertiary sources such as dictionaries, encyclopedias and thesauri are excellent sources for synonyms and related terms.




Many disciplines have developed specialised lists of subject headings or thesauri.  These give not only the preferred term but also synonyms and related terms.

Databases, including MEDLINE, EMBASE, PsycINFO and CINAHL Plus can be searched using standardised subject headings, also known as 'controlled vocabulary'.

Both  MEDLINE and PubMed for instance use MeSH - the Medical Subject Headings.  Other databases have their own subject headings. 

It is advisable to ensure a comprehensive search strategy by utilising both subject headings and keywords.

Benefits of Subject Headings Limitations of Subject Headings
Standardisation of the terms being searched, no matter what terminology an author has used. For example, technical/scientific versus common phrases, synonyms, spelling variations. Subject Headings are applied by indexers,  so are subject to human error.
Can be used to help locate other relevant terms/publications that you haven't yet included in your search. Some databases index publications to a deeper extent than others (more/less subject headings applied, or the subject headings available are broader/narrower)
Can increase relevance where a word has multiple meanings or implications. Newer/cutting edge topics may not yet have appropriate subject headings available. 


Click on the logo to see how this works in:


Other Thesauri

Some other examples of thesauri include:

There are also thesauri in the Library's collection, including

Dictionaries & Encyclopedias

The Library has an extensive collection of general and subject dictionaries and encyclopedias.

These can be useful in identifying terminology and synonyms. 

These can be found by entering your subject into OneSearch and adding dictionaries or encyclopedias to your search.


The Library has some databases of dictionaries, encyclopedia and thesauri which can be consulted online.


Wikipedia can be a great source especially for the scientific names of plants and animals.



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