Which of the following methods involves changing a variable to observe the effects on behavior?

The experimental method is characterized by the systematic manipulation of one or more independent variables to observe the resulting changes in behavior, which are measured as dependent variables. This approach allows researchers to establish cause-and-effect relationships by controlling for other variables that could influence the outcomes. Through experiments, researchers can test specific hypotheses and draw conclusions that are supported by empirical data. In the context of animal behavior, this method is particularly powerful as it enables scientists to isolate factors that might influence behavior, thus providing clear insights into how different variables interact to affect actions and responses in animals.