Truncation, wildcards and other functions

Preparing your search: truncation, wildcards and other functions

Using truncation and wildcards

The easiest way to search for words that look similar is to use truncation, or a wildcard. The symbols will vary according to the search tool you are using (use the help page to find out what symbol to use), but the principles are always the same.


By using the following symbols at the end of a word or word stem, you can retrieve variant endings of that word. Common symbols which are used include * and $.
Example: contamina$ will retrieve references containing the words: 
contamination, contaminants, contaminated, contaminate, contaminates 

Example: market* will retrieve references containing the words: 
market, markets, marketing, marketed 


Use a wildcard to replace a letter in the middle of a word. The symbol ? is often used. 
Example: m?n will retrieve references containing the words ‘men’ or ‘man’ 
Example: colo?r  will retrieve references containing the US spelling ‘color’, or the UK spelling ‘colour’.

Other functions
Field restriction

Most databases allow you to search specific fields. For instance, if you know that David Begg has written a useful paper on your subject, you may want to search for Begg and limit your search to the author field. Similarly, if you have retrieved far too many papers on your chosen topics, you may want to limit your search to title only.


Some databases allow you to apply limits such as language, date of publication, and publication type. Again, if you have retrieved too many references, you may want to limit your search to a shorter date range, or to only retrieve review articles. Specialist databases may have limits particular to the topic. For example, a health and medical database may contain limits specific to patient types, gender and specialisms.