The Three Rs framework of Replacement, Reduction, and Refinement provides the ethical foundation for minimizing animal use and harm in scientific research.
The Three Rs framework represents a structured approach to the welfare challenge of animal research: society derives benefit from scientific knowledge but that benefit must be weighed against the welfare costs to the animals involved. Replacement directly eliminates welfare harm by removing animals from research entirely where scientifically valid. Reduction reduces harm through using fewer animals. Refinement minimizes harm per animal through better methods. The practical implementation of Three Rs requires institutional commitment, researcher training, funding for alternatives development, and regulatory enforcement. The welfare argument for investment in alternatives is compelling: every validated non-animal method eliminates welfare harm for all future studies in that area while often providing more human-relevant data.