Now maybe you are beginning to understand what I'm getting at. Even determining the functionality requires testing the physical parameters.
So in this case functionality is not a valid test. It is superfluous. Remember the purpose of this exercise is to determine a test or tests adequate to test my hypothesis. I think you can realize that it is best to actually look at the rock before you decide exactly what tests to perform. When I picked up the rock it was sufficient to convince me that it was an arrowhead or at least deserved some attention. In order to convince you the tests have to be determined after the hypothesis. As I stated, dried blood does not have the functionality of blood in the veins. It is still blood.
So in this case functionality is not a valid test. It is superfluous.
The most basic fundamental of engineering is that form follows function. You've submitted that it performs a given function, and have implicitly specified the physical parameters it needs to conform to to fulfill that function. Testing one implicitly tests the other, you cannot separate them. It is disingenous sophistry.