Well, in some ways, it's not possible to quite place the SBLM data in the current context, since they're not the same type of scaling, as I've discussed elsewhere. Ratio IQs were more intuitive, I think, to understand in terms of LOG, but also didn't always stand up well moving up through the developmental stages, because of the shape of the curve of normal development over time.

And Davidson probably does not have a deep pool of comparative data on SBLM and other tests, since they did not come into existence until nearly 30 years after the last time the SBLM was re-normed (and about 10 years after the SBIV was released).

The LOGs are more or less modeled after the levels of impairment on the other tail. Which brings up another angle on LOG. At the left tail, the field has moved away from using strict IQ ranges for classifying levels of impairment (at one point, they were strictly by IQ, and basically tracked the LOGs I listed previously, but with the SDs negative instead, and the classifications named mild, moderate, severe, and profound). In recent years, both the DSM-5 and the AAIDD have moved to a "levels of support" model--which is, of course, more positively phrased than "levels of impairment"--but also emphasizes that two adults with the same tested IQ can function very differently. So while measured IQ still plays a role (if you have an 80 IQ, intellectual disabilities are very unlikely to be part of the diagnostic discussion), the IQ score-based descriptors have moved to ones more like
mild = can live independently with minimal support
moderate = can live independently with moderate support (e.g., group home)
severe = needs daily support for self-care
profound = needs continuous care.

Analogously, there might be value in discussing LOG in terms of levels of need as well.


...pronounced like the long vowel and first letter of the alphabet...