section 2.6.4, face validity example would help

[michaeladamkatz]

In all the other sections in this part, there is an example of the kind of validity. An example of face validity would be helpful also -- that is, an example of one or more claims that don't have good face validity, maybe one that actually turned out to be wrong and one that turned out to be right. As I was reading I was trying to imagine a study with poor face validity, maybe something like "Eating bacon makes you smarter," but as soon as imagined that I imagined most people being genuinely interested in the result and willing to entertain the premise. What is the relationship between face validity and the statement "extraordinary claims require extraordinary proof?"