[reikonomusha]

My problem is precisely that these scientific methods are not used when "cognitive load" is being used as rationale. Wouldn't you agree that it would be a mistake for me to claim that cognitive load is an issue with something if e.g. I have not shown that pupils dilate (or some other reasonable experiment indicating correlation)? Unfortunately, doing these experiments is difficult, which justifies "hard to substantiate."

[CuriousSkeptic]

Yes I do think claims should be justified by experiments. Perhaps I'm reading the wrong fora but it seems to me that serious HCI-studies on language design should be happening a lot more than it does.