Is there a site online which details these levels? I don't have Ruf's book. What do the levels tell us? Is it along the lines of Gifted/Highly Gifted/Exceptionally Gifted/Profoundly Gifted? Or something different?

Two books that I do have and thought were interesting are:
Nature's Gambit by David Henry Feldman
and
Exceptionally Gifted Children by Miraca U.M. Gross

I remember reading case studies in these books when our son was very young and being surprised that the case studies were exceptional. At the time, I didn't have much experience with kids and just assumed our son was average. We were involved in a very small neighborhood playgroup of 3 toddlers that consisted of one boy who was clearly a low-functioning autistic and one girl who was what I considered "normal" and now know was PG. At the time I didn't really know the difference. Our son and the girl got along famously. I remember many anecdotes that didn't seem remarkable at the time but now, after having spent time with a wide variety of children, are astounding.

Unfortunately, the little girl's family moved away. At the time I didn't realize how unusual it was for our son to find a friend who was his intellectual peer. Now, our son is yearning to find a friend with whom he can talk about his interests, and I'm sad that we haven't yet found someone(s) for him.

I'm sorry for that tangent.

E