American Medical Association 1992. Use of Animals in Biomedical Research - The Challenge and Response - An American Medical Association White Paper. AMA. Group on Science and Technology, Chicago, IL.

Biomedical experiments are conducted in accordance with the principles of the scientific method developed by the French physiologist, Claude Bernard, in 1865. This method established two requirements for the conduct of a valid experiment:(1) control of all variables so that only one factor or set of factors is changed or at a time, and(2) the replication of results by other laboratories. Unless these requirements are met, an experiment is not considered valid..... Most scientists do not mistreat animals and would prefer not to use animals at all if that were possible. In fact, mistreated or stressed animals do not make good research subjects, particularly in behavioral research.