> Pedagogy is about how children learn, it has less relevance in higher education, which is more about learning how to learn. Andragogy is how adults learn and I invite anyone to see how often that word is used.

It's always amusing to see lectures on correct usage from people who don't know the difference between etymology and meaning. (And also who don't know the etymology, either, since etymologically, pedagogy isn't “how children learn” but more like “the act of leading children”.)

In English, especially American English, “Andragogy” is mostly used in relation to a particular theory/approach to adult education originating with Martin Knowles, who leveraged the same conflation of etymology and meaning—even when it originated, pedagogy was well established with its modern and more general meaning despite the narrower sense of its Greek roots—to promote it; education for different audiences by age or other circumstance is not generally distinguished by different greek-root terms in English, but by English terms [“early childhood education”, “adult education”, “continuing professional education”, etc.)