Evidence requires running good studies. Running controlled studies requires treating some people differently then other people based on arbitrary criteria. Treating everybody the same in front of the law is a basic principle in many countries which discourages the running of controlled studies.
Evidence requires running good studies. Running controlled studies requires treating some people differently then other people based on arbitrary criteria. Treating everybody the same in front of the law is a basic principle in many countries which discourages the running of controlled studies.