Reduce the number of animals used to a minimum, to obtain information from fewer animals or more information from the same number of animals.
Scientists have made a lot of progress in finding ways to reduce the numbers of animals used in experiments. Further reduction may come from more thorough analysis of the findings of studies already conducted (by ‘systematic reviews') and by improving animal models for certain areas of research.
Proper experimental design and statistical analysis of the proposed research project allow the optimum number of animals to be used. If too few animals are used then the results are not reliable and the experiment needs to be repeated, using more animals. If too many animals are used, the results are reliable, but animal life has been wasted.
All other aspects of the experiment must be properly designed and conducted. Good experimental design will minimise variability and reduce bias.
For more on good experimental design, systematic reviews etc see Experimental design & analysis
The National Centre for the 3Rs, set up by the UK government in 2004, funds 3Rs research and promotes exchange of ideas, information and best practice.