Bill Nichols Expository , Poetic, Observational , Participatory, Performative , Reflexive
In Introduction to Documentary notes six types of modes of documentary Nichols 2001 looked at history of documentary and identified 6 distinct modes From Expository to Performative. In a linear progression. With distinct syles. Nichol’s modes is not the only theory of documentary and is not definitive, see Bruzzi below and also look at Grierson’s theories as well as Bazin’s views on realism.