naturalistic observation

n. A research methodology that collects descriptive data via observations of target phenomena occurring in their natural context (as opposed to laboratory research). Naturalistic research involves watching target behaviors, 
events, or phenomena without interference from the researcher; as such, naturalistic observation is one of the most common unobtrusive research methods. The goal of naturalistic observation is to observe and record target behaviors without influencing, controlling, or manipulating the situation. For example, a researcher interested in mating behavior may choose to observe individuals interacting at a dance to examine social interaction in an environment in which people do not know they are being studied. The advantage of this type of approach is that people are not influenced by the research environment; the disadvantage is that there are often ethical concerns with the observation and recording of behavior without the consent of the individuals being studied. – BJM