Participant observation is a qualitative research method where a researcher immerses themselves in a group to observe and participate in their daily lives over an extended period of time. This allows the researcher to gain an intimate understanding of the group's practices, behaviors, and culture. There are various levels of participation a researcher can take, from non-participatory observation to fully embracing the group's customs. While this provides rich insights, it also carries risks like bias and losing objectivity. Participant observation works best when little is known about a topic or setting and a detailed understanding is needed.