The search methods detailed in this tutorial are based on the U.S. Patent Classification system developed and maintained by the USPTO. If you are searching for patents based on subject matter, the U.S. Classification search is most useful. While Keyword searching is useful, complete search results are somewhat unlikely because of the way the search is performed and its dependency on the searcher's ability to guess at key terms or words.

See Classification searching and Keyword searching for other advantages and disadvantages of each search method.