Progress in replacement has been restricted by certain plausible, but untenable, assumptions, summed up as the high fidelity fallacy
References
1.
RussellW.M.S., & BurchR.L. (1959). The Principles of Humane Experimental Technique. xiv + 238 pp. London, UK: Methuen.
2.
TinbergenN., & PerdeckA.C. (1950). On the stimulus situation releasing the begging response in the newly hatched Herring Gull chick. Behaviour3, 1–39.
3.
Russell and Burch used “ignorance” here, rather than “knowledge”. I regret that I cannot discuss this with them, and I hope they would have approved of my change of word. However, knowing Bill Russell, I am sure that he would have been able to explain precisely what he actually meant and would probably have resisted the change.