If it is known beforehand that all the participants will answer in the same way, testing 5 will produce as much information as testing 10000, so the question is

If it is known beforehand that all the participants will answer in the same way, testing 5 will produce as much information as testing 10000, so the question is whether any beforehand assertion like that applies. One reason that assertion might not hold is if the 5 being tested come from a special interest group, knowing if that could be the case or not depends on domain knowledge. http://www.bd.com/vacutainer/labnotes/Volume17Number1/composition_differences.asp http://www.bd.com/vacutainer/labnotes/Volume17Number1/compos... So, it is known that small samples of blood taken from capillaries will have a different composition than large samples taken from veins. Is it possible to write a test that compensates for the known differences? Or is it just known that they are so different that one can't be inferred from the other? Hard to tell, needs cutting edge domain knowledge.