One of the fundamental ingredients of television measurement within content analysis research is the extent of involvement in violence of different types of characters. Two of the five components of the Violence Index measure used by Gerbner and his colleagues in quantifying violence on American prime-time television drama output consisted of the extent of character involvement in violent episodes either as aggressors or victims, killers or killed. Gerbner (1972) argued that the distribution of characters in television drama programmes and the extent to which different types of characters become more involved in violence and the nature of their involvement (i.e., as aggressors or victims) carry important meanings concerning chances and risks in real life for different kinds of people. According to Gerbner (1972, pp. 44-45):
Who commits and who suffers violence of what kind is a central and revealing fact of life in the world of television drama that viewers must grasp before they can follow, let alone interpret, the play…who gets (and gives) what, how and why delineates the social structure of the world of television drama. The distribution of roles related to violence, with their different risks and fates, performs the symbolic functions of violence, and conveys its basic message about people.