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Research skills: finding and evaluating information for essays and theses: Finding information

This guide gives an outline of the key skills needed for researching a subject, from identifying and developing a topic to finding and evaluating information for essays and theses. It also includes advice on writing your essay, assignment or thesis.

Use Keywords

Use keywords, not sentences when searching library databases.

Keywords describe the main concepts or ideas in your research question.

Aim to use between 2 and 4 keywords.

Watch the short video below by McMaster University Library to learn how to use keywords.

Running time: 2:42

Controlled Vocabulary

Controlled Vocabulary can be defined as follows: 

A controlled vocabulary is an established list of standardized terminology for use in indexing and retrieval of information. An example of a controlled vocabulary is subject headings used to describe library resources.  (OECD, Glossary of Statistical Terms)


A controlled vocabulary ensures that a subject will be described using the same preferred term each time it is indexed and this will make it easier to find all information about a specific topic during the search process. (OECD, Glossary of Statistical Terms)


Using a controlled vocabulary means that you can be consistent in your search terms and reduces the risk of errors in your results. The databases available in the library, such as EBSCO Academic Complete, have their own controlled vocabulary or index that you can use. There are also a number of controlled vocabulary sources available in print and online, such as:

Library of Congress Subject Headings (LCSH)

Art and Architecture Thesaurus (AAT)

Cultural Objects Name Authority (CONA)

National Agriculture Library Thesaurus (NALT)

Medical Subject Headings (MeSH)

International Classification of Diseases (ICD)




Tips on searching databases

Using Google for research - some limitations that need to be considered

Tips on searching Google from MIT Libraries