General Discussion
In reply to the discussion: Rickety Woo [View all]Bernardo de La Paz
(49,001 posts)But one's mind should not be so open as to be drafty.
Anecdotal evidence is evidence. But it is only indicative, not definitive. When the friend made the clay pot connection, he had an indication. So he did a study (experiments) and obtained scientific evidence, which is much more definitive.
Another lesson to learn from the story is that "absence of evidence is not evidence of absence". It is only indicative. However, when the absence is repeatedly tested in multiple ways, those indicators can add up to a nearly definitive statement. But technically it can never be definitive.
In this case, the strong anecdotal evidence was sufficient motivation for the friend to continue looking for positive definitive evidence. His persistence paid off, where some might have been satisfied with the "absence of evidence" and written off the anecdotes. His work showed that would have been a mistake.
All the same, it is important not to draw too strong a lesson here. It would be "woo" to persist too long, especially if the anecdotal evidence is not strongly indicative, as it was in the Iroquois case. When one researcher looking at a hypothesis a few different ways fails to find evidence, that is very different from multiple researchers following many lines and failing to find support for a hypothesis.
I would like to know if your friend was able to research the diabetes issue and what he found.