When it comes to database searching, choosing keywords and subject terms is probably the most important- and sometimes the most difficult- step in the research process.
Articles in databases are organized by the subject terms and keywords that describe them. To find the journal articles you need, try to think like an article author. Different authors might use different terminology to describe the same topics or concepts, so keeping a log of all possible terms you may need to search for is vital to a successful search.
Consider the following questions to uncover alternative and keywords for each component:
Who is the patient? What is the population or disorder of interest? What are key characteristics of the patient, problem or population? What health concerns are of interest?
What is the intervention or event? What therapeutic, diagnostic, preventative or other health care actions or processes of interest? What do you want to do for the patient or population?
Is there an alternative intervention? What is the intervention being compared to?
What is the effect of the treatment/intervention? What are the results of the intervention? What are you trying to accomplish, improve, or affect?
Boolean Operators AND, OR, and NOT are used to link your search terms together to either narrow or broaden your search results.
The Boolean Operator ‘AND’ retrieves articles that contain ALL terms. Using AND narrows your search. The example search from the diagram below, stroke AND paralysis, would retrieve articles that contain both terms.
The Boolean Operator ‘OR’ retrieves articles with either/any of the terms. Using OR broadens your search. Typically you will use OR with synonyms or related terms to capture the different words used to describe that concept. Using OR, the example search diagramed below would retrieve any results that included stroke, any that included brain infarction, any that contained ischemia, or any with two or all three of the terms.
The Boolean operator 'NOT' excludes terms from your search. Use NOT sparingly and carefully- if you use it at all- because in addition to excluding articles with the term you do not want, it may also exclude articles that are relevant to your research- but they will be removed from your results if they also contain the unwanted term. For the example diagrammed below, this search would retrieve articles with the term ischemic stroke and exclude articles with hemorrhagic stroke; it would also exclude articles that use both of those terms.
Nesting is a way to combine several Boolean operators into one comprehensive search statement. Most often you'll use parentheses ( ) to separate OR statements. Generally, databases process the search in the order of AND, OR, NOT. Searches within parentheses are performed first and operations proceed from left to right.
Example of a search with nested OR statement:
(stroke OR brain infarction OR ischemia) AND paralysis
Diagrams by Rachel Miles: https://www.flickr.com/photos/184495897@N07/
Most article databases provide an Advanced Search page that will help you structure your search and limit results to more relevant articles.
Enter your search term, then use the drop-down menus to the right to select the search fields you want to target, and between each row, select Boolean operators to connect your search terms.
For example, if my PICO question is 'Among nurses in the ICU (P), does a mindfulness-based stress reduction program (I) decrease the incidence of burnout symptoms (O)?' I could search for the terms nurses, intensive care unit OR ICU, mindfulness based stress reduction, and burnout. Remember, comparison terms are not required if only one intervention is being tested.
This image shows how this search looks in the CINAHL database using the search boxes and drop-down menus:
But there are many more options available on the Advanced Search page! You can find Field limiters in CINAHL to the right of each search box:
Brief definitions of some of the common search Fields you can choose from to narrow your search results:
►Select a Field or Any Field - Will look through all sections of item records for your keywords. This will deliver a larger, more comprehensive set of results.
►All Text - Will look through the entire full text of the items. This will deliver the largest set of results, but they may not always be the most relevant.
►Author - Use when you want to search for a particular author or theorist. Begin by just using the author's surname.
►Title - Will just search through the titles of the items in the database. This will give you a much smaller and relevant set of results.
►Subject - Will look through the subject tags attached to each record. Again, this will give you a smaller more relevant list of results.
►Journal Title/Source – Will search for articles using some or all of the words in a journal’s title
►Abstract - Limiting to an abstract search when looking for journal articles will often give you a relevant, yet comprehensive search. The abstract is the summary at the beginning of a research article
Use subject searching when you know actual/correct subject headings and you want to do a more precise search than you can with Keyword searching.
Subject searching uses subject headings that come from a predetermined list of possible terms and reflect the content of the item. Most academic libraries use Library of Congress Subject Headings (LCSH) for Subject Search of their online catalogues. A subject search is more specific than a keyword search as it looks in only one field of each record - the subject field.
Many databases use subject headings that are exclusive to that specific database. This controlled vocabulary allows for consistency of terms across the database. For example, Medline database uses MeSH - medical subject headings. These subject headings can be found in the database's thesaurus. In thesaurus, subjects are usually listed with broader, narrower, or related subjects. Using the database's thesaurus will help you identify most effective search terms.
If you are unsure of the correct subject terms, use the results of a keyword search to discover subject headings (descriptors) used in the database. Usually, they will appear at the bottom of the article or somewhere in the citation.
Adapted with permission from Atlantic Technological University Library.
Databases offer additional ways for you to narrow down your results and exclude results you don't want. Use database limits and filters to target specific content and generate more relevant results. You can usually find limiters and filters in the form of checkboxes, drop-down menus, and/or date range sliders on the Advanced Search page of databases, or you may see them on the side of your results screen or under the search box. You can learn more about a database's limits or filters by consulting that database's help pages. NOTE: Every database platform looks different, but most offer similar options for limiting your results. Scan your screen to see what your options are or Ask a Librarian for help.
On the Ovid platform, filters are located further down on the results page:
Content adapted with permission from Grand Canyon University Library.
Phrase searching can be useful if you are looking for a very specific, multi-word term. When you use phrase searching, the database will return results that contain those exact words in the exact order they appear in the search box. To use phrase searching, you will put double quotation marks on either side of the multi-word term(s) that you want to search as a phrase.
(Note: single-word search terms do not need to be searched as phrases/put in quotation marks).
For example, if I am looking for therapeutic treatments for a specific type of facial paralysis and I find multiple relevant MeSH descriptor terms, I might want to search for all of those terms using phrase searching and OR:
("facial palsy, upper motor neuron" OR "facial paralysis, central" OR "upper motor neuron facial palsy") AND (therapy OR treatment)
Truncation is an easy way to search for multiple versions of a word. If you remove the end of the word you want to truncate (leaving the root of the word) and replace the ending with an asterisk * this will expand your search to include all versions of the word. Truncating a word can not only give you a greater chance of finding articles on your topic; it will save you time because you won't have to type out all different versions of that word as separate search terms.
For example, we know an article about nurses might use the terms nurse, nurses, or nursing. If we truncate the root word as nurs* this will search any words that begin with the first four letters: nurs. Thus, using nurs* in our database search will retrieve articles that include the terms nurse, nursing, or nurses. More truncation examples:
Wildcards can find multiple versions of a word by using a wildcard character as a substitute for a character or characters at the beginning or middle of a word. For example, a search for wom#n will retrieve both woman and women. (Important Note: not all databases allow the use of wildcards, and different databases may use different characters as wildcards, such as an asterisk or question mark. If you're not sure about using wildcards in a database, look at their help/search tips page for more information). Find information about using truncation and wildcards for the CINAHL database.
Wildcards are also useful for terms that are spelled differently in other parts of the world, such as the American spellings of pediatric or color vs. the British spellings of paediatric and colour. The wildcard searches for those terms would look like this: p#ediatric and colo#r.
Proximity Operators (or adjacency operators) can be used to narrow your search by finding words that are near, next to, or within a specified distance from each other. They are often used when Boolean operator searches are not narrowing down a search enough.
Each database uses different proximity operators. As an example, operators like N (near) or W (within) followed by a number specifies the number of words between each search term. The lower the number, the narrower the search. You can also decide in which order the search terms appear according to each database’s unique operators.
The Near Operator (N) finds terms that are a maximum number of words away, regardless of the order in which the terms appear.
For example, if your PICO question includes the concept of knowledge translation, you could use knowledge N5 translat* to find: knowledge translation, translation of knowledge, translator of knowledge, translated this knowledge, translates clinical evidence into knowledge, and the list goes on and on.
If you want to search for specific words within the same phrase, sentence, or paragraph, you could try the following:
NOTE: Some databases use the Adjacent (ADJ) operator instead of Near.
The Within Operator (W) finds terms that are within a certain number of words and only in the order you entered them.
There are many ways you can revise your search or strategy if search results do not meet your needs.
Pearl Growing, a.k.a. Citation Mining is using articles and sources you've already found to find more relevant articles and sources. If you've got a really good article, chances are you can use it to find more good sources.
Cited In (Backward Citation Mining)
Take a look at the article's References and track down any older sources that seem promising.
Cited By (Forward Citation Mining)
See if you can locate other, newer articles that have cited the article you found. Good resources for forward citation mining are PubMed, Web of Science, and Google Scholar.
Keywords & Search Terms
Look at the keywords and subjects listed for the article to find other potential terms to add to your search strategy.
Related Readings
Some databases will suggest other articles based on the article you've found, and sometimes searching for an article by title in the PNW Library Catalog will bring up related articles.
Browse Journals
Search for or browse the journal the article published by, or use PNW Library's Journal Search to find other journals in the field.
Author Stalking (not really) & Thought Leaders
Search for other articles, books, websites, and blogs by that author- they may have published more on the topic! You can also search professional organizations or institutions, social media, and the internet in general for recommended authors and leaders who are writing about your topic. Always practice due diligence and research authors to ensure they are reliable sources.
Cochrane is a specialty database that publishes systematic reviews, attempting to identify, appraise, and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a specific research question. Far smaller in size than CINAHL or Medline, the Cochrane Library is an excellent resource for finding systematic reviews.
This specialty database from the Joanna Briggs Institute spans a range of medical, nursing, and healthcare specialties and includes evidence summaries, systematic reviews, best practice guidelines, and more. JBI does not draw their contents from published journals like many of our database resources; they publish their own research. It is a vastly smaller database than CINAHL or Medline, but a great source of high-quality systematic reviews.
5-minute video provides an overview of:
