Step Five - Combining your 'concepts'... with Boolean Operators
To combine the different concepts of your search question you will need to use boolean operators. Boolean operators are 'logical operators' which enable you to broaden or restrict a search. The main logical operators are 'OR' and 'AND'. To illustrate how they work, cast your mind back to Venn Diagrams taught at school:
In the example above, using the 'OR' operator for the concept of pressure sores will retrieve articles which mention either 'pressure sores' or 'decubitus ulcers' or 'bed sores'.
Using the 'OR' operator for the concept of beds will retrieve articles which mention either 'beds' or 'mattres*'.
Using the 'AND' operator will retrieve a subset of articles which mention 'pressure sores' or 'decubitus ulcers' or 'bed sores', but also mentions 'beds' or 'mattres*', that is, the intersection of the two concepts.
In practice you need to type each term into the database separately, to see which terms are working most effectively, and then combine them. It is best to do all the words or phrases from each concept, in term.
Try performing a search on Medline using the pressure sores example.
1. Type in all the terms relating to pressure sores (including MESH headings
and synonyms), and combine these terms using the 'OR' boolean operator.
2. Type in all the terms relating to beds (including MESH headings and synonyms),
and combine these terms using the 'OR' boolean operator.
3. Combine the results of the two sets using the 'AND' boolean operator.
4. Display some of the results and check the relevance of articles retrieved
to the search question.
| To complete this question you will need to search Medline database.
Remember to use the 'toggle' function to move between web pages. Once you have completed the task, 'toggle' back to this page to continue to tutorial. |
Welcome Back!
Now try our quiz to see how much you have understood about using boolean operators.