[schoen]

An interesting thing about LLPSI is that it does include abstract discussion of grammatical rules and concepts - in Latin, once readers have learned enough to permit following the discussion.

So it's not just learning from example and trying to pick up grammatical rules intuitively. Like when I took my German class, it was taught by immersion but included discussions, conducted in German, of how grammatical rules work. LLPSI is also attempting to do that kind of thing.