Experimental Design: A research design that involves the manipulation of one or more independent variables to observe their effect on a dependent variable, while controlling for other factors that may influence the outcome.
Correlational Design: A research design that examines the relationship between two or more variables without any manipulation, aiming to determine the strength and direction of the association.
Observational Design: A research design that involves the systematic observation and recording of behavior or phenomena in their natural environment, without any intervention by the researcher.