Observational research is type of correlational (i.e., nonexperimental) research in which a researcher observes ongoing behavior. There are a variety of types of observational research, each of which has both strengths and weaknesses. These types are organized below by the extent to which an experimenter intrudes upon or controls the environment.
Naturalistic Observation: Naturalistic observation, also known as nonparticipant observation, has no intervention by a researcher. It is simply studying behaviors that occur naturally in natural contexts, unlike the artificial environment of a controlled laboratory setting. Importantly, in naturalistic observation, there is no attempt to manipulate variables.
Strength: We can measure what behavior is really like. After all, the researcher is observing real-life. This type of research, then, has high ecological validity (the extent to which a situation generalizes to real-life circumstances).
Click here to read Observational Research