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Agriculture and Natural Resources

PICO Search Framework

The PICO method of search was initially developed for use in health science research. However, the fundamental strategies of the PICO method can be utilized effectively for scientific research in many disciplines. PICO helps a researcher identify the key terms that should be included in a search. PICO is an acronym that stands for:

P - Patient: what is the population that are you interested in? Think of this as the subject of your research.

I - Intervention: what is the exposure or intervention that you are interested in? Think of this as the independent variable in an experiment. 

C - Comparison: what is the comparison to the current intervention? What other factors could be considered as an alternative to the main intervention? For many types of research, this step can be ommitted.

O - Outcome: what are you hoping to measure or improve? Think of this as the dependent variable in an experiment.

While this process may seem formulaic, it helps identify terms that should be included in your search strategy. By doing this BEFORE you attempt to do a search, you can ensure that you will not waste your time looking at search results that are not relevant to your research.

For additional resources on PICO, please see the links below. Need more help applying PICO or creating a search strategy? Contact a librarian!

Develop a Search Strategy

Searching Strategies

Choosing your topic can be a difficult process - it is important to pick a topic that is not so narrow that little if anything has been written about it, yet it is also important to pick a topic that is not so broad that there is too much information and it is impossible to develop a coherent and focused thesis.

Let's say that ....



1. Divide your research question into concepts and connect them with the Boolean operator AND.

  •  cucumber AND waxing AND Salmonella

2. Brainstorm some synonyms and connect them with the Boolean operator OR:

  • cucumber* OR "Cucumis sativus" OR “gherkins, etc. 
  • Species identifiers?
    Use USDA Plants, ITIS - Integrated Taxonomic Information System, or IPNI - International Plant Names Index
  • Similar technical terms?
    Look them up in NALT - National Agricultural Library Thesaurus

3. Your final search strategy could look like:

(Cucumber* OR "Cucucmis sativa" OR gherkin*) ​AND (wax* OR "edible film*" OR "edible coat*") 
AND (Salmonella OR "Bacillus cholerae*") 
NOT juice


Try using the Search Strategy Builder from Georgia State University to explore your own concepts!


A brief video tutorial on how Boolean operators work.


Search Strategy Builders

In order to get the best results from electronic indexes and full text databases, you need to have a well constructed search strategy. These resources provide strategies for developing focused searches that will yield useful results. If you're still not finding the results you need, contact a librarian for more assistance!

Public Health Databases

These databases are great places to find original research articles as well as review articles.

Need more help creating your search? Check out the tab on Crafting A Search.

Searching Tips

Searching techniques to limit or expand your results






Find all the words

Find any of the words

Find documents which have the first word, but not the second word

internet AND education

internet OR intranet

internet NOT html




Search for an exact phrase by using quotes around the phrase

 "environmental health"

Truncation *

Find all forms of a word - the asterisk * is used as a right-handed truncation character only.

Searching for econom* will find "economy", "economics", "economical", etc.

Wildcard ?

Replace any single character, either inside the word or the right end of the word. ? cannot be used to begin a word.  

Searching for wom?n will find "woman" and "women."




It is important to realize that if you search a database with a certain word or phrase and you don't retrieve results to your liking, it doesn't mean that there are no other articles in that database on your topic. It may mean that you need to try other related words in your search, such as synonyms. For example, try automobile or auto instead of car.

Using Zotero

Citation and Avoiding Plagiarism