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Database Searching

This LibGuide is meant to illustrate database structure and how to search databases according to their design. This LibGuide is meant to be directed toward searching Medical and Life Sciences databases.


Use NOT in a search to:

  • exclude words from your search
  • narrow your search, telling the database to ignore concepts that may be implied by your search terms

Example:  Dementia NOT Alzheimer's

Using the Research Question & Boolean Operator NOT

The Boolean operator NOT is typically used in two instances. 

1. You run a search and get results. Within the results you notice that a keyword (typically) has inadvertently brought in many things outside the scope of the topic/question. For example, a researcher conducts a search on football with the intention of retrieving articles about American football. Therefore, the researcher searches football* as a keyword. Many articles may come in the results that are about European football, or soccer as it is typically called in the United States and Canada. In this instance the researcher may want to add to their search history a line that looks like: football NOT soccer*

2. To test a search! This is incredibly important for systematic searching. For example, the question used throughout this LibGuide you can test a new keyword you can add to the results. An example is exhibited below in PubMed, where the researcher is looking at the difference between the results whenever adding the keyword JUUL to the electronic cigarettes concept.