Truncating – derived from the word “trunk” – is the omission of (usually) the last part of a word, the part after the stem, which is replaced by a truncating symbol, sometimes called a wildcard. Wildcards can vary per database. The most common symbols are *, #, ? and %.
Some databases only allow truncating to the right, while others also permit left truncating.
One drawback to truncating is that there is a greater chance of “static”. Static means that the hits also include documents that are of little or no use. A general rule is the more precise and specific the terms chosen, the less static will be result from the search.
Example of truncating:
Masking (or hiding from view, concealing) involves the use of a masking symbol (wildcard) to leave open specific letters in a word. Masking is useful when you have a keyword that could be written in different ways and you are not sure of the exact spelling, or you wish to leave it open.
As with truncating, there is a greater chance of static with masking.
Example of masking: