In online research, truncation refers to the ability to search for all word variations that begin with a certain root without typing each word. On both Westlaw and LexisNexis, you can place an exclamation point (!) at the end of a root to find the root plus all words made by adding letters to the end of the root. The exclamation point is referred to as a root expander or truncation device.
For example, a search for mediat! will find occurrences of the terms mediate, mediates, mediated, mediating, mediator, and related terms.
The trick to using truncation is knowing how much of the root to include. In the above example, including one letter too many in the root and searching for mediate! would miss the terms mediating and mediator. On the other hand, including one too few letters and searching for media! would retrieve many terms that you didn't want, including media, medial, and median.
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