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Evidence-Based Practice: Tips for Searching the Literature

How Do I Search PubMed?

How do I search PubMed?

  1. Identify the key concepts for your search. 
  2. Enter the terms (or key concepts) in the search box.
  3. Press the Enter key or click Search.

For many searches, it is not necessary to use special tags or syntax. PubMed uses multiple tools to help you find relevant results:

  • Best Match sort order uses a state-of-the-art machine learning algorithm to place the most relevant citations at the top of your results.
  • An autocomplete feature displays suggestions as you type your search terms. This feature is based on PubMed query log analysis described in “ Finding Query Suggestions for PubMed .”
  • A spell checking feature suggests alternative spellings for search terms that may include misspellings.
  • A citation sensor displays suggested results for searches that include terms characteristic of citation searching, e.g., author names, journal titles, publication dates, and article titles.

https://pubmed.ncbi.nlm.nih.gov/help/#how-do-i-search-pubmed

PubMed Tutorials

UpToDate Tutorials

Conducting a Search in UpToDate


Using the UpToDate App

Searching Cochrane Library

AND/OR/NOT

Two is better than one

Think about it: search engines crawl thousands, maybe even millions and billions, of pages or records trying to match your search term with results. You're going to be absolutely overwhelmed with results if you only enter a single search term. You're also going to find a lot of completely irrelevant stuff.

So how can you improve your chances?  

Come up with multiple search terms and combine them using the options described here.

Venn diagram highlighting the area of overlap between the two circles.

Combining search terms with AND will:

  • Reduce the number of results
  • Make the search focus more specifically on your topic

Search for "college student"  = 1.2 billion results 

Search for politics = 296 million resultsAdvanced search examples show how to select AND to connect multiple search terms

Search for "college student" AND politics = 43 million results more focused on your topic

Search for "college student" AND politics AND "2008 election" = 543,000 more relevant results

Combining search terms with OR will:

  • Expand your search and increase number of results
  • Give your search flexibility to find alternate terms

Search for film  = 601,786 resultsEBSCO search for movie or film

Search for movie = 199,781 results 

Search for film OR movie  = 642,906 results that mention either film or movie, or both


Search for "middle school" = 21,401 results that mention "middle school"EBSCO search for "middle school" or "junior high"

Search for "junior high" = 7,261 results

Search for "middle school" OR "junior high" = 28,177 results that mention either "middle school" or "junior high", or both

Combining search terms with NOT will:

  • Decrease your search results
  • Increase the relevancy of your results by telling the search to exclude certain terms

Search for "Hunger Games"  = 745 results Demonstrates the advanced search "Not" feature of EBSCO

Search for "Hunger Games" NOT movie = 487 results 

 


Search for cloning = 42,736 resultsBasic EBSCO search bar: cloning NOT human

Search for cloning NOT human = 30,325 results

Search engines attempt to match your terms to the items it searches (titles, authors, abstracts, description fields, full text, etc).

However, search engines do NOT understand phrases, sentences, or questions. So when it does this matching, it searches for each term indivdiually. Some searches attempt to find terms in proximity to each other, but this varies depending on where you search.

Quotation marks to the rescue

If your search terms are more than single worlds, employ quotation marks to show the search engine that you want the terms to be found together. The search will look for exactly what you place in the quotation marks, so be sure there are no mistakes.


Search for Adam Smith = 38,700,000 results

Search for "Adam Smith" = 2,730,000 results


Search for theory of relativity = 3,430,000 results

Search for "theory of relativity" = 856,000 results

Truncation

Truncation is a way of giving your search tool flexibility to find alternate endings for your search term.

Why it's helpful:  Search engines match your terms to results; they will not find an alternate version of your term. Truncation tells the search to match the root of your term and gives it freedom to find whatever endings it can.

Truncation symbols include question mark, number sign, asterisk, and exclamation point.

Examples:

  • Gene! will bring back gene, genes, genetic, genetics, genetically, general, generally, etc
  • Liv* will bring back results for live, lives, lively, livelihood, liver, livery, etc
  • Child$ will bring back child, children, childrenhood, etc

How to do it:  Shorten your search term to its base or root form. Then add a truncation symbol to the end of your term. Note: truncation symbols vary by search tool.

Truncation Symbols by adstarkel. Used under CC BY-NC-SA 2.0.

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Email Butler University Libraries
Irwin Library: 317-940-9227
Science Library: 317-940-9937

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