>Yes you can define reading comprehension to mean that.

You don't have to define it thusly, though. Whatever SAT tests test for, this is already the dictionary meaning of the term. The except was from Wikipedia.

Here's a dictionary lemma too: comprehension: "a test to find out how well students understand written or spoken language" (listening/reading comprehension).

It's not argued that domain knowledge doesn't factor tremendously in understanding. Just that this is not a reading comprehension intends to measure (heck, the hint is in the very combination of the words that make up the term).

Of course in order to understand some text in a reading comprehension test, domain knowledge will also help.

But reading comprehension is not about any particular domain -- and tests in that don't constraint themselves to only present texts about a specific subject.

Reading comprehension, as you are defining it, is not what the SAT (and most other standardized reading comprehension tests) is actually measuring. That's it. That's the entirety of my point.