Observer Effect: The changes in an individual's behavior when they are aware they are being observed. Like how animals might act differently if they know David Attenborough is watching them!
Field Study: A type of study where research is conducted outside the laboratory, in its natural context – similar to naturalistic observations but may involve some level of interaction with subjects.
Ethnography: A qualitative research method often used in social sciences, particularly in anthropology and sociology, involving close observation of social practices and interactions.