The purpose of this review is to evaluate the current status of scientific knowledge on intimate partner violence (IPV) and sexual violence, with a particular focus on the measurement of gender patterns. A multimethod analysis of estimates for the incidence and prevalence of intimate and sexual aggression reveals consistencies across some methodologies and inconsistencies across others. In particular, self-report using behavioral checklists such as the Revised Conflict Tactics Scales yields results that are very discrepant from other research findings. Contrary to some assertions, self-report studies using simple checklists do not represent "most data" on intimate violence; there are large criminological and public health databases that warrant attention. When these sources are considered and placed in the context of other data on violence and aggression, a clear pattern of gender asymmetry emerges, with males perpetrating more physical and sexual violence than females for virtually every form of violence ever studied. Violence research has been hampered by the conservative forces that affect most social science research, including peer review, grant review, and tenure review processes that discourage methodological innovation and reward incremental research studies. We need to focus resources on scientific and technological innovation to better understand violent phenomena and better serve all those involved in violence. Two examples of self-report methods that do not produce gender symmetry are described.