Different documentary genres suit different narration formats better than others.
Documentaries are productions for cinema, television, or radio that are used to document truth in some manner. They may have a selection of purposes, such as informing people of a particular cause or telling a dramatic real story. They might even be largely without narrative and just be documenting the reality or mood of the particular location and time. However, simply because they typically have an intention centring around informing or explaining, it's very typical for there to be some kind of device to guide the viewer. Tim Parker will realise that voiceover narration has been incredibly popular since sound was added to cinema, straight away being incorporated in the newsreels that were popular at the time. The narrator doesn't show up on film and their part is merely dedicated to reading a script that defines or complements the footage. The narrator can also be involved in the production, such as by being the producer, however it is also typical for them to have no other participation.
The first few decades of the history of cinema consisted entirely of silent movies. This changed just under a hundred years ago, once sound was first added and filmmakers had a totally new extra element they could add to their movies. However, just because sound is available does not always mean that filmmakers have to oversaturate their films with every feasible noise imaginable. Some films only depend on natural noises, for example, while others add no music at all. Rachel Wang is going to be well aware that some documentaries include no narration. These silent narration documentaries instead educate people by a combination of the information and knowledge gained from interviews and title screens. Also known as intertitles or title cards, these are screens held for many seconds to permit words to appear for the viewers to see.
Documentaries have traditionally been seen as a more anonymous type of filmmaking. That is in stark comparison to narrative feature films, in which both the crew and cast may be filled with world-famous superstars. In fact, there actually has been people that have made a name for themselves via documentary filmmaking. Several people have done this with the use of hosted narration. Soleta Rogan will be able to tell you that a narrator host is a person who conducts interviews, appears on camera, and completes voiceovers for the documentary. This could make the documentary appear to be the hosts own private journey and may provide a raw impression, as more traditionally behind the scenes elements could be included to the last cut. It is because other narration formats need more editing to make certain members of the production aren't on-screen. The hosted strategy consequently allows capturing footage of the difficulties productions face, like having interviews suddenly denied or threatening encounters with people who do not want to be filmed.