News values are "criteria that influence the selection and presentation of events as published news". These values help explain what makes something "newsworthy".
Initially labelled "news factors", news values are widely credited to Johan Galtung and Mari Holmboe Ruge. In their seminal 1965 study, Galtung and Ruge put forward a system of twelve factors describing events that together are used as defining "newsworthiness". Focusing on newspapers and broadcast news, Galtung and Ruge devised a list describing what they believed were significant contributing factors as to how the news is constructed. They proposed a "chain of news communication",:65 which involves processes of selection (the more an event satisfies the "news factors", the more likely it is selected as news), distortion (accentuating the newsworthy factors of the event, once it has been selected), and replication (selection and distortion are repeated at all steps in the chain from event to reader). Furthermore, three basic hypotheses are presented by Galtung and Ruge: the additivity hypothesis that the more factors an event satisfies, the higher the probability that it becomes news; the complementary hypothesis that the factors will tend to exclude each other; and the exclusion hypothesis that events that satisfy none or very few factors will not become news.
