In the study of literature, an audience surrogate is a fictional character with whom the audience can identify, or who expresses the questions and confusion of the audience. It is a device frequently used in detective fiction and science fiction.
In detective fiction, the audience surrogate is usually a minor character who asks a central character how he or she accomplished certain deeds, for the purpose of inciting that character to explain (for the curious audience) his or her methods.
In science fiction, the audience surrogate frequently takes the form of a child or other uninformed person, asking a relatively educated person to explain what amounts to the backstory. Clumsy use of this device is derided in the catchphrase "As you know, Bob, ...".
In superhero comics and other stories with a heroic central character, the audience surrogate is often the sidekick of the hero. Like the audience, the surrogate is normally young, permitting the audience vicarious participation in the hero's adventures.
Hobbits fulfill this role in J. R. R. Tolkien's novels The Hobbit and Lord of the Rings. Dr. Watson in Arthur Conan Doyle's Sherlock Holmes stories may be considered an audience surrogate, as would most of The Doctor's many companions in Doctor Who. In Torchwood, this role is filled by Gwen Cooper, and later her husband Rhys Williams. Harry Potter also served this role in the earlier books in the series, but decreasingly so in the later books as the character became more accustomed to the Wizarding World; Eragon is used similarly in the Inheritance Cycle because he knows nothing about magic, dwarf, or elvish customs. Examples from criminal and police procedurals include Seeley Booth in Bones and Anthony DiNozzo in NCIS.
The West Wing television series frequently uses audience surrogates to explain some aspect of politics. Donna Moss is probably the most commonly used, but other characters are used occasionally in areas which are outside their own fields of expertise.