Gerbner's initial work looked specifically at the effects of television violence on American audiences. Measuring the effect of violence underscored the larger part of Gerbner's work on cultivation theory. Therefore, he measured dramatic violence, defined as "the overt expression or threat of physical force as part of the plot." Gerbner's research also focused on the interpretation by high-use viewers of the prevalence of crime on television versus reality. He argues that, since a high percentage of programs include violent or crime-related content, viewers who spend a lot of time watching are inevitably exposed to high levels of crime and violence.