HDG, I see what you mean. One example, if there are 10 studies in the past without ss, and someone did the 11th trial to reach ss, is it obvious? You can argue either ways as clearly the 10 prior ones show the desire but I would say before the 11 th, it was non-obvious.
I see it come down to the definition of POSA, as would a POSA like Du who may simply look at the numbers but ignor the ss to draw obvious conclusion.