Kerbouchard - I'm still confused - mostly because its not Understanding exposure which says that ISO is part of exposure, but every single guide I've ever read concerning photography (some written before UE) - heck I only got the book after learning most of exposure and whilst I keep the copy it didn't give me many revelations.
In the end I'm still coming to the same conclusion that Exposure is a word with (at least) duel meanings - one within the photography world of the average photographer - and another within the scientific based world that photography is founded upon. As such, and since this is a photography forum not a physics forum, it still stands to confuse most when you take the science angle (even in beyond the basics) directed at a majority of the population who are not scientists/physicists.
It's highly likely that a large number of us need to read far more into the physics behind photography in order to appreciate the "error" that you are attempting to correct; but when that "error" in terminology is used throughout the whole of the photography hobby/practice with (as far as I've noticed) no suitable alternative being suggested/used - then it does appear to me to be a duel world meaning situation based on the context of the discussion at hand.
Except that it's not a dual word meaning. Nobody has produced even one link to a credible or recognized source saying ISO is a part of exposure. On the contrary, all of mine, and several of the references have said, that indeed, ISO, is not technically a part of exposure. The scientific definitions don't match how you use it. The dictionary definitions don't match how you use it.
Dude, I don't know what else to say. Just because a bunch of people use a word to mean something other than what it does, doesn't mean it's right. Honestly, I can't argue with your logic. You get your point across to others like you.
IMO, in the next few years, Webster, will probably add another footnote in the definition of 'exposure' to appease people like you. At that point, I won't have a leg to stand on...a bunch of morons will have successfully changed the definition of a word. It won't be the first time that has happened.
Until then, ISO is not a part of Exposure. Period.
P.S., show me one source that explains how to measure ISO in 'Lux Seconds', which is the standard unit of measure for exposure.