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You will often be asked to find literature on a topic or to answer a research or clinical question. Whether you're looking to learn about something new, or dive deep into a topic of existing interest, you can search for relevant information using the library's subscriptions and databases. For more information on searching and conducting a literature view, check out our recommended guides (left side of screen on desktops). 

Research vs Non-Research

During your search, you will want to distinguish between articles that report on research, and those that are considered non-research. Research can be any time of primary research such as a randomized controlled trial, a cohort study, and both qualitative and quantitative studies; it can also be secondary research such as a systematic review or a meta-analysis. Non-research may report on research, such as in the case of most literature reviews (ie scoping reviews, integrative reviews, etc.), includes practice guidelines that draw from existing research, reports on quality improvement initiatives or other programs, or provide expert opinions. Each type of material can be valuable, and your choice of what to include in your search will depend on your information need and your research question. 

For more on research and non-research, read Chapters 6 and 7 of "Johns Hopkins evidence-based practice for nurses and healthcare professionals model and guidelines". 

Background vs Foreground Questions

You will want to consider whether your question is a background question or a foreground question. From Weinfeld & Finkelstein:

Background questions generally ask “who, what, when, why, where or how” about a single disease, drug, intervention or concept.

Foreground questions always compare two things: two drugs or treatments, the prognosis of two groups, two diagnostic tests, or the harms or benefits of two approaches. [Such as PICO questions]

Weinfeld, J. M., & Finkelstein, K. (2005). How to answer your clinical questions more efficiently. Family practice management12(7), 37–41. 

Where to Search

Information can be found in a wide variety of locations. For scholarly books and articles, you will likely find the best material using the library's subscriptions and databases. To identify which databases to search, use the Resources page of this guide. This page also lists our available point-of-care tools for use in the clinical setting, and also collections of academic books (such as textbooks), which can be used to answer background questions. 


Frameworks for Questions


From BMJ Best Practice:

The PICO (Population, Intervention, Comparator and Outcomes) model captures the key elements and is a good strategy to provide answerable questions.

Population: who are the relevant patients or the target audience for the problem being addressed?
     Example: In women with non-tubal infertility

Intervention: what intervention is being considered?
    Example: …would intrauterine insemination…

Comparator: what is the main comparator to the intervention that you want to assess?
     Example: …when compared with fallopian tube sperm perfusion…

Outcomes: what are the consequences of the interventions for the patient? Or what are the main outcomes of interest to the patient or decision maker?
     Example: …lead to higher live birth rates with no increase in multiple pregnancy, miscarriage or ectopic pregnancy rates?


How to clarify a clinical question. (n.d.). BMJ Best Practice. Retrieved October 26, 2022, from


From "Formulating the Evidence Based Practice Question":

Setting: What is the context for the question? The research evidence should reflect the context or the research findings may not be transferable.

Perspective: Who are the users, potential users, or stakeholders of the service?

Intervention: What is being done for the users, potential users, or stakeholders?

Comparison: What are the alternatives? An alternative might maintain the status quo and change nothing.

Evaluation: What measurement will determine the intervention’s success? In other words, what is the result?

Davies, K. S. (2011). Formulating the Evidence Based Practice Question: A Review of the Frameworks. Evidence Based Library and Information Practice, 6(2), Article 2.



From "How CLIP became ECLIPSE":

Expectation—what does the search requester want the information for (the original ‘I’s)?
Client Group
Impact: what is the change in the service, if any, which is being looked for? What would constitute success? How is this being measured?
Service: for which service are you looking for information? For example, outpatient services, nurse-led clinics, intermediate care

Wildridge, V., & Bell, L. (2002). How CLIP became ECLIPSE: A mnemonic to assist in searching for health policy/management information. Health Information & Libraries Journal, 19(2), 113–115.

Search Strategies

Once you have identified the key concepts of your research question (see "Developing a Question"), you can use those concepts to develop keywords for your search strategy. The following tips and techniques will help you design a precise and relevant search strategy.

Keywords are any words you might use to search the record of an article, book, or other material in library databases. The database searches through the metadata (such as title, authors, publication, abstract, etc.) to find resources that contain the word you searched, and may also search through the full text of the material.

Keywords are most successful when you're searching for the words that the authors use to describe the research topic, as most databases will search for those specific words within the record of the article. To increase your chance of returning relevant results, consider all of the words that might be used to describe the research you're trying to find, and try some of these out in sample searches to determine which words return the best results.

Search Tips - Keywords

  • Search for singular and plural terms together: (physician OR physicians)
  • Search for both the American and British spelling of words: (behavior OR behaviour)
  • Search for synonyms of terms together: (teenager OR adolescent)
  • Search for phrases inside of quotation marks: ("young adult")

Use Boolean operators to combine keywords for more precise search results. 

AND - If the term must be included in your search:

influenza AND vaccine

OR - If terms are interchangeable, i.e. synonyms. Place OR'd terms within parentheses:

(influenza OR flu) AND vaccine

NOT - If a term should not be included in your search. This Boolean operator is rarely necessary for literature reviews.

(influenza OR flu) AND vaccine NOT H1N1


Note how we've used parentheses in the examples above. Search strings like these are similar to mathematical equations, where you perform the actions within the parentheses before proceeding from left to right to run the search. For example, using the search [(influenza OR flu) AND vaccine] will find results that have a term relating to influenza/flu, as well as the term vaccine.

If we moved the parentheses, it would be a very different search. [influenza OR (flu AND vaccine)] will provide results that use the term influenza, as well as results that use both the terms flu and vaccine. This means you would get results having to do with influenza but perhaps nothing to do with vaccination. 

Here are a few examples of how this search would be different depending on the arrangement of booleans and keywords. The area highlighted in pink represents the search results that would be returned with this search.

(influenza OR flu) AND vaccine

flu OR (vaccine AND influenza)

(vaccine AND influenza) OR (influenza AND flu) OR (vaccine AND flu)

Truncation allows you to quickly include all variations of a word in your search. Use the root of the keyword and add an asterisk (*). For example:

nurs* = nurse, nurses, nursing, nursery

IMPORTANT: Notice that "nursery" is also retrieved in the above search. Truncation will save you from having to include a large number of synonyms, but it will also add a certain number of irrelevant results. You can limit this effect by using the NOT Boolean operator, i.e. NOT nursery.

Wild cards allow you to replace a letter in a keyword to retrieve all variations of the spelling. For example:

p?ediatric = pediatric, paediatric

Citation Searching

Citation searching is a search strategy that allows you to search either forward or backwards time through the literature based on an identified relevant article:

You can search forward in time by using databases that allow you to search for other articles that have cited the identified relevant article. (Web of Science and Google Scholar can do this automatically.)

You can search backward in time by reviewing the reference list of the identified relevant article for additional article citations.

For more information about how to perform citation searches, check out this guide from the University of Toledo Libraries:

Free-Text vs. Thesaurus Searching

While you can search any word as a keyword, databases also contain an official list of the terms they use to describe the subject of each article, called Subject Headings. You can look up Subject Headings in the thesaurus of the database, using the thesaurus's search box to pull up the recommended Subject Heading for a given keyword. When searching specifically for Subject Headings, the database will only search the Subject Headings field within the record of each article (ie, not the title, abstract, etc.). This is a much more targeted method of searching, and is an excellent addition to your search strategy. 

A strong search strategy will use both free-text (keyword) searching and thesaurus searching, to ensure that all relevant articles have been retrieved by the search. The lists below outline the strengths and weaknesses of both types of search strategies.

Free-Text Searching
  • Natural language words describing your topic
  • More flexible search strategy - can use any term in any combination
  • Database looks for keywords anywhere in the record - not necessarily connected together
  • May yield too many or too few results
  • May yield many irrelevant results
Thesaurus Searching
  • Pre-defined "controlled vocabulary" words used to describe the content of each item in a database
  • Less flexible search strategy - need to know the exact controlled vocabulary term
  • Database looks for subjects only in the subject heading or descriptor field, where the most relevant words appear
  • If too many results, you can use subheadings to focus on one aspect of a broader topic
  • Results are usually very relevant to the topic

MIT Libraries. Database Search Tips: Keywords vs. Subjects.

Each database has their own thesaurus. You will need to adapt your search strategy for each database to take advantage of their unique thesaurus.

PubMed uses MeSH terms (Medical Subject Headings). You can learn more about finding and using MeSH terms here:

CINAHL uses CINAHL Headings. You can learn more about finding and use these terms here:

In other databases, look for a link with the terms "headings", "subject headings", or "thesaurus" to find the appropriate thesaurus terms for your search.


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