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Health Sciences Research


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 that is used for a number of databases such as MEDLINE, Embase, PsycInfo, EBM Reviews (i.e. Cochrane Library) etc. The examples and screenshots provided are from Ovid MEDLINE and may function or appear slightly different on other Ovid databases. Similar principles apply to other search platforms. 

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: childhood AND obesity. Narrows results
  • Use OR to include related terms or synonyms for a concept: childhood OR adolescence. Broadens results

Considerations for searching:

It is not always necessary to include all of your main concepts in the search. For example, in some PICO questions, the outcome is implied and does not need to be included. In other cases, any and all outcomes might of interest and so the search strategy can leave this out to keep it open.

Basic Searching

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, the Ovid search above will search for children as a related term for childhood, but not adolescents. You can review what related terms the database includes to the left of the search results to understand how your search was interpreted (see below)
  • In the search information below you can also see that obese was included as a related term for obesity
  • 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. For example: physical activity adolescent obesity, or, exercise childhood obesity


Advanced Searching

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 (more on this under Subject Heading Searching), 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. For this reason, enter your search terms one line at a time as shown in the screenshot 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: exercis* will retrieve exercise, exercising, exercises
  • Use carefully, as truncating short root words may also retrieve undesired terms: searching advi* to retrieve records with advise, advice, advising etc. will also retrieve records with 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

Managing Search Results

In the banner that precedes the search results, you can select citations that you like to email yourself or export to a citation manager. Note, if printing or emailing at least one citation, you can also include the search history.