Keyword searching: truncation and wildcards
2004 version 2
24 May 2004
Word stemming (truncation) and wildcards
We've already found that to search for a particular word stem with any of a number of possible endings add the character $ to the end of your initial string of characters and before the two character field code, eg practi$.tw. will retrieve practice, practices, practitioners, as well as other words you may not want like practicalities or practised. Be careful not to make the word stem too short. This will take a long time to search and may retrieve irrelevant material.
You may specify how many characters you are willing to accept after your basic word stem by adding a number after the $ character. For example, type ovar$3.ti. to retrieve item where the word stem ovar is followed by 0-3 other characters.
The mandatory wildcard character # can be used within or at the end of a search term to substitute for one required character. For example, type wom#n.ti. to retrieve items with titles containing the word woman or women. A character must be present in the position denoted by the # in your search term for an item to be retrieved. You may use multiple mandatory wild card characters in a single query.
The optional wildcard character ? may be used within or at the end of a search term to substitute for one or no characters. For example, type
gyn?ecology.ti. to retrieve items with titles containing the word gynecology or gynaecology. You must have at least two characters before the position denoted by the ? in your search term to be able to use this facility.
Figure 29: Result of wild card title search for gynaecology
You may use multiple optional wild card characters in a single query. A summary of these and other shortcuts is in Appendix 6 .
Any questions? Please contact the MEDLINE Plus help desk:
Tel: 020 7383 6224 or 6737
email: info.medline@bma.org.uk
web: http://www.bma.org.uk/medline