In some instances, a plaintiff in a negligence action may rely on a statute to prescribe a certain standard of care. Under the doctrine of negligence per se, a standard of conduct required under a statute is adopted by a court as defining the conduct of a reasonable person. In other words, rather than asking a jury what a reasonable person would have done under certain circumstances, the statute establishes what a reasonable person would have done under those circumstances. A statutory violation under this rule is conclusive on the issue of whether the defendant violated a standard of care.