In non-participant observation, researcher; observes from a distance without participating in the activities. Naturalistic observation is a form of non- participant observation.
The researcher takes care to see that he exerts minimal impact on the situation being observed. There are occasions when non-participant observation is not possible. In order to observe the marriage customs and marital life in a tribal society, it is not possible to stand back and observe the process. The subtle and sensitive aspects of a situation would only be available to a participant observer. The nature of observation would depend on the interest and requirement of the researcher.