Criminology journals around the world reveal many different approaches to criminology. These approaches derive from legal scholarship, medical research, sociology, economics, and other social sciences. Empirical criminology has at least three major forms: (1) formulation of hypotheses about crime based on a holistic understanding of a wide range of evidence; (2) hypothesis testing; and (3) analysis of flaws in a particular hypothesis that may produce invalid or unreliable conclusions. Manning concludes from his research that policing makes no difference in crime, and other scholars have reached a similar conclusion. The concept of the "preventive conceit" of police effectiveness is applied to domestic violence and to police practices in Australia, and the influence of jurisprudential epistemology on criminology is addressed. 14 references