Animal behavior is studied by construction of an ethogram—a listing and description of all naturally observed behaviors. Behavior can also be studied through the use of manipulative investigations, both in the field and in the laboratory. In order to be objective, all observers must record behavior patterns in exactly the same way; observations can then be statistically analyzed. For example, animal behavior can be sorted into broad categories (such as courtship and feeding) or into more specific patterns (such as an attack, chase, and/or aggressiveness).