A taxonomic key is a method used to classify and identify objects and organisms. It shows a series of choices about the characteristics of different organisms. A user picks from these choices and ultimately finds the identity of a specimen.
Also called a dichotomous key, a taxonomic key gives users a systematic and reproducible way to identify items and organisms. It is used for a variety of purposes, such as identifying unknown organisms to a certain taxonomic level (e.g. family, genus and species) and identifying rocks or minerals. Taxonomic keys are commonly used by scientists, researchers and students. They are ordered in a manner that leads the user to the correct identity of a particular item. Every dichotomous key has a recognizable starting point. Two choices are always provided at every level. These choices contain descriptions of key characteristics of an organism. The paired statements or choices consider the similarities and differences between items. Physical traits are best observed for easier identification of objects. After choosing the statement that best matches the object, a user proceeds to another pair of statements until the name of the item is identified. Taxonomic keys have many possible end results. Each final identification typically shows a complete description of the object. Some keys contain information on numerous species, while others provide concise information.