In many bibliographic databases, online catalogs, and search engines it is possible to refine searches using a technique called "truncation." Truncation allows you to search for variant forms of a word as a single search concept, rather than identifying and entering variant words of the keyword as individual concepts. Variations of words in keyword searches can be searched simply by adding or replacing characters at the end, beginning, or middle of the word with a truncation symbol, also known as a "wildcard." This wildcard "stands in" for the part of the word that may have variations. Common truncation symbols include *,#,$, and ?. Some databases may even use more than one of these symbols with specific criteria for their use. 

Sometimes there can be too much of a good thing. Truncating too early at the end of the word can broaden the search to unrelated topics. For instance, truncating a word to gen* to retrieve topics related to genetics and genomics will also pick up many words that are totally unrelated. 

When preparing to truncate your search term, it is important to know the scope of the resource being used as well as what truncation symbol(s) is used, which is usually a simple visit to the resources "Help" section.