This document defines and provides examples of observational documentaries. Observational documentaries follow subjects without interviews and use minimal equipment like handheld cameras to observe events in their lives. The goal is to allow subjects to forget the cameras and behave naturally. Examples given include the reality show Big Brother, which hides cameras throughout the house to observe housemates' natural behaviors without them being aware they are constantly filmed. Clips from Big Brother demonstrate techniques like hidden cameras and voiceovers that are characteristic of observational documentaries.