Using AND, OR and NOT with your Keywords
se AND in a search to:
- narrow your results
- tell the database that ALL search terms must be present in the resulting records
- example: cloning AND humans AND ethics
The purple triangle in the middle of the Venn diagram below represents the result set for this search. It is a small set using AND, the combination of all three search words.
Be aware: In many, but not all, databases, the AND is implied.
- For example, Google automatically puts an AND in between your search terms.
- Though all your search terms are included in the results, they may not be connected together in the way you want.
- For example, this search: college students test anxiety is translated to: college AND students AND test AND anxiety. The words may appear individually throughout the resulting records.
- You can search using phrases to make your results more specific.
- For example: "college students" AND "test anxiety". This way, the phrases show up in the results as you expect them to be.
Use OR in a search to:
- connect two or more similar concepts (synonyms)
- broaden your results, telling the database that ANY of your search terms can be present in the resulting records
- example: cloning OR genetics OR reproduction
All three circles represent the result set for this search. It is a big set because any of those words are valid using the OR operator.
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: cloning NOT sheep
