Ethnography is based on fieldwork. In order for Chagnon to create this film about the Yanomamo people, he had to take part in their events he was observing, describing, and analyzing.
The process of ethnography involves conducting fieldwork. For Chagnon to make a documentary about the Yanomamo people, he had to immerse himself in their daily life by participating in key events and gathering detailed information through observation, description, and analysis.