The article proposes a conceptualization that sees prevalence as the extent to which violent behavior is distributed in the population and incidence as the amount of violent behavior that occurs among those in the population who experience violence. The calculation of prevalence and incidence rates is exemplified with respect to interpartner violence using Statistics Canada’s Violence Against Women Survey. Using duration as an independent variable, the article illustrates how the choice of incidence or prevalence rates may affect the operation of risk markers. Given the need for standardization, the relative ease with which this can be accomplished and the knowledge that research in this area will be conducted well into the future, the article concludes with a plea for a standard use of prevalence and incidence among family violence scholars. Tables, figures, references