Journalism involves the collection, preparation, and distribution of news through various media. It serves the purpose of disseminating and analyzing information as a public service. Journalistic integrity is based on principles of truth and accuracy. The forms of journalism have diversified and include investigative, broadcast, photo, and advocacy journalism. Modern journalism is increasingly participatory through social media. Historically, Walter Lippmann and John Dewey debated the role of journalism in democracy in the 1920s. Their perspectives still influence discussions around journalism's social responsibilities. A journalist is defined as someone who regularly gathers, processes, and shares news to serve the public, though this definition excludes some unpaid citizen journalists.