It is not a specific method of teaching science. As a matter of fact, almost all science begins with observation. Several hundred years were devoted to accumulating a large amount of observed descriptions of nature.
A systematic study of behaviour in the natural settings is called naturalistic observation. It is very critical to the development of scientific knowledge. Behaviours which otherwise cannot be observed in experimental settings can be studied through naturalistic observation.
While conducting observations, the investigator may take the role of either a participant or non-participant observer. In participant observation, the investigator actively participates in the group activities, and thereby, becomes a part of the situation that is observed.
In non-participant observation, researcher; observes from a distance without participating in the activities. Naturalistic observation is a form of non- participant observation.
In subjective observation, which is also called introspection, a person observes his own mental activities. Introspection literally means, "Looking within". It means getting insight into one's own mental activities. In introspection, a person perceives, analyses, and gives a report of his own feelings and experiences.