Reduction of the number of animals used to obtain a certain amount of knowledge with the requisite precision.
Reduction comprises instances where a smaller number of animals can be used in a given situation in a specific experimental model than previously. Consequently, reduction must always be a target for lowering the number of animals used for generating a certain amount of knowledge and not as a target for whether a given organisation, state or company has reduced the overall number of animals within a given time frame compared to corresponding previous periods of time.
The development of animal models with a view to enhancing the scientific results achievable from each individual animal is therefore also considered reduction. Reduction can be obtained using measures such as screening with animal-free models or technologies prior to animal testing, by using animals with the exact characteristics that one is interested in or by designing more systematic experiments.