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Want more help?

All databases should have a Help page that is usually located in the top right-hand corner. There you will be able to find more information about the contents presented on this library page as well as additional search functionalities.

Want even more help? 

Request a research consultation with a librarian.


Research databases often give you the choice of performing a basic or advanced search (note that most library databases accessed via Queen's University Library will default you to the advanced search).

A basic search can be incredibly helpful when looking for a few good articles on a topic or when you're doing some preliminary searching/work. However, a basic search is not recommended if your intention is to perform a comprehensive search. Further, many search topics are complex and it can be to your benefit to use advanced search functionalities. When completing assignments with a literature search component, many instructors want to see evidence of an advanced search that demonstrates a deeper understanding of how databases work and function.

The following page works through search options available on the Ovid platform/interface. You can search a number of different databases via Ovid such as MEDLINE, Embase, PsycINFO, Cochrane Library, Global Health, etc. The examples and screenshots provided are from the Embase database and may function or appear slightly different on other databases available via Ovid. 


Identifying Key Concepts and Search Terms

Using a framework to develop your research question can help to identify the main concepts of your inquiry. Whichever framework you use, try to identify the key/main concepts of your question and the synonyms / related terms that might be used to describe each of those concepts:

Image from UCSF Library: 

Combining search terms with AND or OR:

  • Use AND to combine different key concepts of your search: smoking AND insomnia. Narrows results
  • Use OR to include related terms or synonyms for a concept: Nicorette gum OR nicotine gum. Broadens results


Basic Search

The basic search in many databases operates similar to conducting a Google-type search:
  • Search terms are generally ‘AND’-ed automatically
  • The search algorithm usually attempts to include related terms (ex. searching "childhood" may retrieve "children")
  • Results are often sorted/displayed by relevancy rather than publication year
  • Generally a quick and easy way to locate some relevant records on a topic

Basic search in Ovid databases:

  • Basic search retrieves records where your search terms (and related terms) appear in the record title, abstract, author keywords, database-specific subject headings etc.
  • The basic search mode does not allow you to combine search terms with OR. If you use OR in basic search, Ovid will just ignore the command. If the basic search is not including the necessary synonyms and related terms you want in the search, you can run different iterations of the search by substituting different synonyms and related terms (read more below)

Including related terms in Ovid databases:

  • Like a Google search, many databases will try to include related terms for your search terms. These database algorithms work at a very basic level. For example, using the search term child may retrieve results with the related term children, or childhood, but not necessarily adolescents
  • You can review what related terms the database includes to the left of the search results to understand how your search was interpreted
  • The displayed results will highlight your exact search terms in yellow, and related terms in purple
  • If the database does not include the related terms you are interested in, you can run different iterations of the search by substituting different synonyms and related terms 

Advanced Search

Many databases will allow you to conduct an advanced search. In contrast to conducting a basic search, an advanced search gives the searcher more control and often does not include related terms (instead the searcher will use OR to combine synonyms and related terms). Many databases will also allow you to use advanced search options such as truncating search terms to find alternate word endings (see below). 

Advanced search in Ovid databases:

  • At Queen's, the default search option for Ovid databases is advanced search
  • If records in the database have been indexed with database-specific subject headings, advanced search will try to map your search term to the appropriate subject heading by default. To turn this feature off and search for your terms in the record title, abstract, author keywords, database-specific subject headings, and other fields, uncheck this option directly below the search box:


Combining searches in Ovid databases:

  • Advanced search does not automatically AND your search terms like basic search does, rather your search terms are searched for as a phrase (side by side in the order entered).
  • For this reason, enter your search terms one line at a time as shown below.
  • After searching one line at a time you can then select lines that you would like to combine using AND or OR
  • If you prefer to have less search lines, you can OR synonyms and related terms on the same line and then combine search lines for each key/main concept using AND


Truncation in Ovid databases:

  • Adding an asterisk (*) to root words allows you to find variations of a term and can save you from having to OR related terms for singular, plural and other versions of the word
  • For example: cancer* will retrieve cancer, cancers, cancerous
  • Use carefully, as truncating short root words may also retrieve undesired terms: searching advi* to retrieve records with advise, advice, advisory, advising etc. will also retrieve records that discuss Advil

Database Limits

Most databases will allow you to narrow your search results by applying limits. The options will vary by database but often include limits for publication date, publication types, age groups and language. 

Limits in Ovid databases:

  • You can view limits underneath the main search box
  • If you would like to see even more limit options, you can select "Additional Limits" below


  • Additional Limits includes a filter for clinical trials. Select all clinical trial types listed or select specific types of clinical trials
  • Note that in Embase, limiting to clinical trial study designs also retrieves records that discuss clinical trial research. This means you can retrieve records that aren't actually research studies, unfortunately