Item response theory analysis of intimate-partner violence in a community sample.
ABSTRACT The Revised Conflict Tactics Scale (CTS2; Straus, Hamby, Boney-McCoy, & Sugarman, 1996) is a widely used measure of physical, psychological, and sexual aggression as well as injury and negotiation between partners. In this study, we analyzed male-to-female and female-to-male physical aggression using data from 453 community couples. We used item-response theory (IRT) to assess the range and precision of physical aggression severity in the past year, as evaluated by the CTS2. Our analyses support a single dimension of physical aggression with quantitative, rather than qualitative, differentiation between minor and severe physical aggression items. Surprisingly, test information curves revealed that male perpetration and victimization items provided as much or more information as their counterpart female victimization and perpetration items over the same range of aggression severity. Finally, the data suggests that CTS2 items best assessed moderate-to-severe levels of physical aggression in the previous 12 months. However, virtually no information was assessed by male or female reports of perpetration or victimization items below or around the mean of aggression (i.e., theta; θ = 0). Suggestions for improved item coverage and implications for the assessment of aggression are discussed.