About Searching
When you search library databases, you will use keywords related to your research topic. Then use the keywords to combine them using Boolean Operators into search strings (or phrase searching) to improve your search. Boolean Operators are simple words (AND, OR, and NOT) that are used to connect and define the relationship between keywords.
Remember that the database can't interpret what you mean, so you have to be clear and specific with your searches in order to control the results.
PICO, Keywords, and MeSH Subject Headings
PICO Framework
Used to frame and answer a clinical or health care related question. The PICO acronym stands for P - patient, problem or population; I - intervention; C - comparison, control or comparator; O - outcome.
PubMed Health Glossary (Source: Wikipedia)
Related terms: PICOT, PICOS, PICOTS
PICO acronym for the model of a clinical question for a search strategy or systematic review of healthcare intervention PubMed Health
What is MeSH?
MeSH (Medical Subject Headings) is the NLM controlled vocabulary thesaurus used for indexing articles for PubMed. You can use these in combination with keywords in your searching.
MeSH is:
- an acronym for Medical Subject Headings.
- the U.S. National Library of Medicine's controlled vocabulary (thesaurus).
- a vocabulary that gives uniformity and consistency to the indexing and cataloging of biomedical literature.
- a distinctive feature of MEDLINE: Description of the Database.
- arranged in a hierarchical manner called the MeSH Tree Structures.
- updated annually.
MeSH Vocabulary includes four types of terms:
- Headings
- Subheadings
- Supplementary Concept Records
- Publication Characteristics (or Types)
Truncation Searching
Truncation is a technique that broadens your search to include various word endings and spellings.
- To use truncation, enter the root of a word and put the truncation symbol at the end.
- Examples:
child* = child, childs, children, childrens, childhood
genetic* = genetic, genetics, genetically
Wildcard Searching
| Symbol | What it does | Sample search | Instead of typing |
| * | replaces zero or more letters at the end of a word (this is truncation) |
comput* | computer OR computing OR computational OR... |
| # | replaces at most one letter | ne#t | net OR neat OR next OR nest OR... |
| ? | replaces only one letter | b?t | bat OR bet OR bit OR bot OR but OR... |
REMEMBER: Some databases may use these symbols differently or may use different symbols, so check the database's help section if you're having problems with wildcards.