Experimental Design: Experimental design refers to the specific setup of an experiment, including how participants are assigned to different groups and how variables are manipulated, in order to determine cause-and-effect relationships.
Survey Method: The survey method involves collecting data through questionnaires or interviews from a sample of individuals in order to gather information about their thoughts, opinions, or behaviors.
Observational Study: An observational study involves observing and recording behavior in its natural setting without any intervention or manipulation of variables. It is used when it is not possible or ethical to manipulate variables directly.