1. Expository Documentary
Expository documentary is a mode of documentary which focus’s on social problems within the world.
It emphasises rhetorical content.

2. It usually uses a voiceover which is used to drive the narrative.
This is a much more spoken in relation to poetic who leaves the audience to gather the information via visual interpretation.
Nichols described the editing in expository documentaries as “evidentiary editing,” a practice in which expositional images “...illustrate, illuminate, evoke, or act in counterpoint to what is said…[we] take our cue from the commentary and understand the images as evidence or demonstration…” (Nichols 2001)

3. Example of Expository
– The inconvenient truth.

4. Observational

5. Unlike the content of poetic documentary, or the “rhetoricalness” of expositional documentary, observational documentaries tend to simply observe, allowing viewers to reach there own conclusions.
The camera is unobtrusive. Allowing the events to occur naturally.
Pure observational documentarians proceeded under some bylaws: no music, no interviews, no scene arrangement of any kind, and no narration.
The fly-on-the-wall perspective is championed, while editing processes utilize long takes and few cuts.

6. Example of Observational
Big brother