Documentaries construct a particular version of reality through film techniques used to position viewers to respond in specific ways. They mediate meaning by providing an interpretation of the subject between the viewer. Documentaries aim to record, reveal, persuade, analyze or express while entertaining, educating, informing or persuading audiences. Viewers expect content to be grounded in the real world presented objectively. Documentaries can be categorized into expository, interactive, observational, and reflexive modes using styles like travel, diary, fly-on-the-wall, docu-soaps, and investigative forms with values of educating, illuminating issues empathetically, and social/political criticism or analysis.