kaŝperanto:
They did demonstrate correct usage, but in teaching an English audience the use of that term may be damaging to the basic understanding of adverbial participles. I can see that maybe putting a familiar term to use may trick people into being comfortable with them, but maybe an explanation that they are (approximately) a subset of English gerunds may be apt. I think the use of -ado for true verb-nouns is more clear than using -ing for both.

In this case you should contact the site's owner. It isn't really helpful to complain on a forum that the site owner probably doesn't read, that the site contains incorrect information.

erinja:

kaŝperanto:
They did demonstrate correct usage, but in teaching an English audience the use of that term may be damaging to the basic understanding of adverbial participles. I can see that maybe putting a familiar term to use may trick people into being comfortable with them, but maybe an explanation that they are (approximately) a subset of English gerunds may be apt. I think the use of -ado for true verb-nouns is more clear than using -ing for both.

In this case you should contact the site's owner. It isn't really helpful to complain on a forum that the site owner probably doesn't read, that the site contains incorrect information.

I actually have looked into contacting the author; just haven't yet had the time to compose a message.