Simple Summary Efforts to improve the design of animal studies have tended to focus on the
more mathematical aspects, such as randomization, blocking and statistical analysis. There
are, however, many other factors that affect the data from preclinical studies. To improve
validity, scientists must collaborate closely with the animal facility involved as soon as the
decision to use animals has been made. Such discussions will also help to improve animal
welfare, as well as any health and safety issues. A large number of guidelines have been …