There are two types of observations in sociology, participant and non participant. Key words that go with observational methods are covert (secret, undercover) and overt (participants aware being watched – think back to the Hawthorne effect).
Interpretivists would employ the participant covert observation as it allows for deep understand of perception and emotion within a societal group however poitivist would see this as a case study whichever has low scientific value. Positivist would more likely to conduct non participant observation. These can also be covert but equally they could be overt. The non participant observation allows researchers to observe people in their natural environment and researchers record their behaviours either to a preset behavioural categories list or taking qualitative notes. The obvious disadvantage with this type of observation is you no longer have the indivudal perception.
The secret life of four year olds is a non participant observation, two psychologist observe the children through one way glass.
Participant observation, Non participant observation, Covert, Overt.