Scientists love to preach the importance of "double blind" studies because in that way they can compare their "old" toxic sludge to their "new" toxic sludge in the same study. but in many cases, a double blind study makes no sense in the world. For example, how could you do a double blind study comparing a person who refuses all orthodox cancer treatments with someone who goes through chemotherapy? It is a stupid concept, because after one day a person would know which group they were in.