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Library Online Tutorial for BRE366

About Module 3

In this module, you will learn to:

  • Identify keywords from your research question
  • Build a search statement
  • Improve your search with Boolean operators, exact phrase search, etc.
  • Refine search results with filters

Build a Search Statement & Search Effectively

Once you have developed your research question and identified some sources, you need to develop a search strategy that will enable you to locate materials in order to address your research question. You could always search by typing in one or two keywords related to your concepts, but a well built search statement will help you find relevant results quickly and more effectively

There are couple of "techniques" to improve your search, such as Boolean Operators (AND, OR and NOT), exact phrase search, truncations, and subject headings (i.e. the indexed terms in a database). Follow the suggested steps below to get an idea of building a search statement. These techniques can be used in OneSearch and many other article databases. 

Selecting and using keywords from Joshua Vossler [3:50]

Step 1. Select keywords from your research question/topic

Watch the video "Selecting and using keywords" to learn how to pick keywords from a research question and how many keywords work the best. 

Let's assume you are interested to research the impact of the revitalization of historical buildings in Hong Kong. The keywords you picked are:

 revitalization, historical buildings, Hong Kong 


Step 2. Connect your keywords with "AND"

Use AND to combine the keywords so that the search results will include all these keywords. AND helps narrow your search. 

Use quotation marks " " to enclose the phrase if you hope to search the terms as a phrase (exact the same wording). " " also narrows your search and make your search more precise, but sometimes may yield very few results.

 revitalization  AND  "historical building AND  "Hong Kong

  returns 134 results in OneSearch, as of Sept 2019

You can use OneSearch Advanced Search or other article databases (e.g. Web of Science, Scopus) to build your search statement. 


Step 3. Add synonyms and combine them with "OR"

You might miss out certain articles if the keywords selected were not those used in research papers. Think what could be other alternative keywords authors used in their papers and add them as keywords too. Use OR to combine the alternative keywords (or synonyms) so that articles containing at least one of the keywords will be included in the results. OR helps broaden your search. 

Use parentheses ( ) to enclose the phrase to specify the order (terms within parentheses will be executed first and then AND). 

 (revitalization  OR  revitalizing)
 AND  ("historical buildings"  OR  "old buildings"
 AND  "Hong Kong" 

 returns 373 results in OneSearch, as of Sept 2019


Step 4. Refine your search statement

Don't target for a perfect search statement at your first try. It is very common to refine your search statement until you retrieve a manageable number of relevant results. You may discover new keywords or even refine your research topic during the searching process.

For example, you may consider narrowing down to one aspect after several rounds of searching.

 (revitalization  OR  revitalizing
 AND  ("historical buildings"  OR  "old buildings") 
 AND  "Hong Kong"
 AND  "social impact"

 returns 25 results in OneSearch, as of Sept 2019

Step 5. Refine your search results

At any stage of searching, you can always refine your search results by applying filters, e.g. limit to "peer-reviewed journals", a publication year range, etc. You will see the similar filter options in many other article databases. 

Read More Search Tips below to learn more about Boolean Operators, Truncations, Wildcards, Exact Phrase search, and keywords/subject heading search.

More Search Tips

Boolean Operators (AND, OR and NOT)

  • AND combines search terms so that each result contains all of the terms. AND narrows your search.
    e.g.: youth AND drug finds articles that contain both youth and drug.

  • OR combines search terms so that each result contains at least one of the terms. OR is often used to connect synonyms or similar concepts. OR broadens your search.
    e.g.: youth OR teenager finds articles that contain either youth or teenager or both.

  • NOT excludes terms so that each result does not contain the term that follows it. NOT narrows your search.
    e.g.: drug NOT alcohol finds articles that contain drug but exclude alcohol.

Search Order of Boolean Operators

NOT AND > OR (in most databases, including OneSearch); Use parentheses () if you need to override the order. 

 youth OR teenager AND drug finds articles that contain either youth (only), or teenager and drug (both words are present);
(youth OR teenager) AND drug finds articles that contain either youth and drug (both words are present) or teenager and drug (both words are present).

Truncations & Wildcards

  • Truncations (*) and wildcards (?, #) are used to broaden your search.
  • e.g.:
    comput* searches computer, computers, computing
    colo?r searches color, colour
  • ‚ÄčTruncation and wildcard symbols may vary by database. Check the Help page in the database to learn the symbols and operators that database supports. (or, google database name + "operator" to locate the search help page directly)

Exact Phrase searching with quotation marks ""

  • Quotation marks "" are used to search an exact phrase. They narrow down your search results.
  • e.g.:
    "knowledge sharing" searches only the phrase knowledge sharing and will NOT search knowledge creation and sharing (additional words in between) or knowledge shared
  • Usually quotation marks cannot be used with truncation or wildcards. e.g.: "knowledge shar*"
Use truncations or wildcards when you need more results; use quotation marks when you need less and more precise results.
An example to give you an expression of the number of results retrieved when using different symbols. (in OneSearch, as of 2 Aug 2017)

Keyword searching vs. Subject Heading searching

  • Keywords are natural language words or phrases that describe the search topic. Keyword searching looks for the keyword terms in any field of the record (if not specified) in a database.
  • Subject headings are a group of "controlled vocabularies" that describe the content of each item in a database. These controlled vocabularies are usually given by subject specialists or indexers. Subject heading searching looks for the subject heading terms in the subject heading field of the record in a database.
    The field name may vary by database or platform. e.g.: in OneSearch, it's called "Subject"; in EBSCOhost, it's called "Subject Terms".
  • Subject headings are extensively used for searching biomedical literature. Medline uses MeSH, which stands for Medical Subject Headings. Embase uses Emtree. Both MeSH and Emtree allow using subheadings to narrow to one aspect of the subject.


  • Subject heading searching helps you find articles by "meaning".
    e.g.: search "knowledge management" by Subject returns results that may not contain the phrase "knowledge management" but discuss organizational learning (which is a related subject to knowledge management).
  • Some databases can recommend subject headings when you do a keyword searching. After that you may select appropriate subject headings to search again.
    e.g.: EBSCOhost uses "Suggest Subject Terms"; Medline (via EbscoHost) uses "Map Terms to Subject Heading".