Good questions. I listened to the session recording and that provided some answers.
The 138 to 159 was his typo on the slide. He corrected it on the audio to 138 to 144 for HG modern.
He said there are no universally accepted terms to describe these LOGs and sometimes PG is described as 145 and above.
He discussed GAI and used it in some of the profiles. It seems the same number ranges are used for GAI.
He discussed how the older scores are ratio scores and weren't meant to fit a standard curve. This is why they aren't comparable to the modern scores.
He mentioned a book called
Gifted Children Myths and Realities by Winner. One of the myths is that gifted children are globally gifted.
His website is
www.palmerlearning.com and he has links for parents. Coincidentally I'd just read his book
Parents Guide to IQ Testing and Gifted Education after hearing about it on this site.
It was a 59 minute presentation but I thought it was useful and got my laundry folded while listening.
