Gifted Issues Discussion homepage Forums Identification, Testing & Assessment Levels of Giftednes

Is anyone aware of an up to date statement or table, from a reasonably reputable source, to define levels of giftedness on current IQ tests (ie the WISC-V, with or without extended norms).

So much of the literature about highly, exceptionally or profoundly gifted children still references the SBLM, or other ratio based formats.

When guided to read the work of Miraca Gross for example, how does a parent with a child who has current IQ scores make sense of where their child fits within the context of Miraca's work (obviously one will find stories which are more or less relatable in a qualitative sense).

So this is Deborah Ruf's article on the SB5's extended norms, written under the auspices of the publisher.

SB5 ASB3

This is Linda Silverman's definitions of LOG. She collected data for, and helped to develop, the WISC-IV and -V extended norms:

GDC HG/PG

They are both referring to deviation IQs (contemporary test design, not the ratio IQ of SBLM days), and use essentially the same 1 SD brackets for each tier of GT-ness, with +2SD G/MG, +3SD HG (highly), +4SD EG (exceptionally or extremely), +5SD PG (profoundly). Ruf also includes an approximate concordance table for SBLM to SB5 comparisons.

Thanks AEH, I had not seen that one regarding the SB5. I will take some time to digest it.

With the second I had to stop myself from skimming and go through a second time, it reads like one I have read before, which did not seem to have been updated, but indeed it does have current references despite the start (where numbers are mentioned) seeming identical to an older article.

So those numbers are quite out of step with Davidson's requirements to join DYS or apply to their school (not an option for us anyway due to location). And also the Hoagies Gifted "Levels of Giftedness" which are often recommended as a guide.

The SBV article seems to clearly lay out the problem I am grappling with. But I can't seem to highlight text to quote any of it to discus here.

It seems to both be saying "We are still setting the boundaries at the same sorts of standard deviations, but our current tests don't really allow you get there." The artcile includes references to test subjects with SBLM scores over 200 and SBV scores below 145 and this is described as reflecting the nature of standard score vs ratio IQs, not the "Extremely high abilities" of the subjects.

This article doesn't really help with clarifying how to understand, in a current context, all the literature written about children identified and described using the SBLM.

Does Davidson have such a chart showing correlations between SB 5 and LM? Seems like they would have accumulated quite a data base.

This webpage from Hoagies Gifted Education Page may be of interest:
Highly, Exceptionally, Profoundly Gifted

Not exactly what you are asking for in your post, but may also be of interest...

...from Hoagies:
- WISC, WPPSI V SB-LM
- Don't throw away the old Binet
- About SB5...

...from members of this forum:
Old discussion thread WISC-IV V SB (November 2011)

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.

You've received great info from aeh, as usual.


To clarify, when comparing scores between various test instruments, a collection of paired scores from each of the test instruments is assembled and analyzed. Each test-taker will have taken both of the tests, and submitted the documentation of their test scores.

This Hoagies' webpage describes the process: Data Collection: Old and New IQ Test Score Pairs

It may a bit like contriving an equivalence table between ACT scores and SAT scores... each of which measure different things.

Thank you both.

Indigo I had read many of of those articles before, MANY years ago, the "Don't throw away..." article was particularly helpful to re-read in the current context. The discussion you linked to I was part of :-), amusing trip down memory lane.

This makes sense to me. What would you propose the levels of need would be on the right hand side of the distribution?