The document discusses several techniques used in documentaries to convey information to audiences in an authoritative and believable manner. It notes that a constant voiceover acts as a narrative to pass information to viewers, while an assertive voice implies the speaker is knowledgeable. Additionally, documentaries aim to present real, unaltered footage and include interviews from experts to appear more authentic. Non-diegetic music is also used to create effects and influence audience perceptions of what they see. Mise-en-scene and props help layout footage naturally for viewers.