Hey! I've been thinking about the tests in the Wechsler series and is after 12 years of interest still not letting go. I've written a few times on this forum and I think I can say that it's the most insightful forum I've come across that deals with psychometric testing.

Now, I mostly want to rant about what I've thought about and it comes down to the division of General ability index (GAI) and Cognitive proficiency index (CPI).

Interesting fact that its common among highly scoring individuals to have a separation between these two where the CPI is far lower then the GAI. As far as I can understand GAI includes how well you can do things, its a bit odd however because I want to think of GAI and CPI as dependent on each other. For example I found that higher GAI makes you do less errors on Coding.

So one question would be, "What is the impact of lower CPI when you have a high GAI?".. I've read threads from years back and sometimes you can have a scaled score of 4-6 in coding and a 18 in similarities.

If you would pinpoint, what difference does it make to your performance if this kinds of difference is present?
My first concern would be that the process of using the "ability" would be slower and more prone to error. But what if your just a slow thinker? Is coding more reliant on executive functions?

What would be a core description of the process? Is processing speed only the speed at which things are done, thoughts, writing etc? Where does working memory come into this, as it is a part of the CPI?

Basically I believe that he CPI as an efficiency measure which tells us how good someone is at using their abilities, which is close to executive functions but wouldn't the GAI scores be lower of you couldn't use your abilities to its fullest? Maybe its the timed tests that suffer most from lower CPI..

What is the "qualitative" relationship?

These are my thoughts in covid times..
Thank you!

With coding in particular, there is major confounding due to the need for sensory motor control (handwriting) and good visual processing & visual memory. Strengths or weakness in both these areas will also impact some of the subtests that make up the GAI (block design for example) but others may not be impacted at all.

Using the two subtests you mention is a particularly good example because a blind person with no hands could score 18 on similarities just as much as any other person might be able to, and would be completely unable to undertake the coding subtest at all, despite possibly having quite excellent executive function.

Also with coding, the person being tested has to actually be motivated to do such a thing in some sort of timely manner. Ask me how I know.

How do you know KAI?

I read a book by Heelen Braaten about processing speed and also found her on youtube. She's a specialist on the topic. She claims that people who have deficits in processing speed are slow to complete tasks. That's all.. That's what all that stuff is about. It's not mysterious at all..

However I've suffered due to this.. All the years in school when pen and paper has been the standard I've barely received a grade. At university I aced all the online exams and got nothing when the time to sit down and write came.

It's unfair that I have all the answers but is unable to show that because of the style that we have to present information.

GAI of 125
CPI of 85

If the person taking the test doesn't push themselves to go quickly or worse, drags their feet the entire time, the score will be lower, sometimes far lower, than if they had.

One of my kids was like this. He had us all convinced that he had a processing speed deficit that was getting worse over time. He was also homeschooled, and my impression of his processing speed was that it was sometimes lightning fast and sometimes dismally slow--and tests of processing speed seemed to be designed to bring out his dismally slow side.

Fast forward to his high school years, where he was able to finish the SAT in half the time and still get all (or almost all) of the questions right.

But more generally, when you use test results to infer something essential about a person (intelligence, for example), there is an implicit assumption that the person was trying to do their best when taking the test.

I have one of these! I have said the exact same thing to various professionals in their lives "Slow and deep... also, sometimes lightening fast"



Mine is horrified at the suggestion that they should have (and use) extra time...


Our recent report explicitly states that child worked hard and it was a "Valid" and accurate result... No actual explanation for the very bizarre pattern of strengths and weaknesses. We often hear about a child with some indexes very strong, other's weaker (ie strong VCI, weaker PS or WM). My child managed to have nearly two standard deviations between the two subtests in most indexes (except VCI which was even, and VSI with only one deviation). Even AEH struggled to find a pattern if I recall correctly. Tests that might normally clump together just don't (ie two tests which rely heavily on visual memory and no motor component) and areas that I know are personal strengths have scored relatively poorly compared to relative weakness in day to day life.

I don't think this was a conscious act on the part of my child. But I am not fully on board with the psychologist that the test results accurately reflect best effort or accurately capture my child's strengths and weaknesses. Except in so far as my child has a problem with very variable engagement and performance.

My thoughts goes to the form of expression desired.. For example I scored low on Coding which measures speed, fine motor and visual memory but high on block design which also measure speed, fine motor and something similar to visual memory.. I don't know if the difference is that its visual vs spatial but that's the pattern

Concerning what you're good out the mode of output is important. Coding is doing something boring which taxes your flexibility (executive function) a lot while block design is more complex and requires problem solving to a larger degree.

I think it's extremely important as an assessment professional to maintain a level of humility with regard to any client, but especially for low-incidence learners like twice-exceptional students. Even for those of us who may have encountered a few more of them than others. There's an old principle in assessment along these lines: interpret the test in the context of the child, not the child through the lens of the test.

I've come to understand how processing speed works on a deeper level and my interpretation is that processing speed is the speed with which we can make basic information useful to us.

A way to explain this is to give someone a number, say 1. This is a basic piece of information and its easy to interpret. How quickly did you make sense of the 1?

Now the spread would be that all information requires making sense of before we can use it and I have found that I have an excellent spatial working memory but slow "coding" or visual processing speed.

This means that I can take huge stretches of information but it takes time for me before that information becomes understandable.
This shows up in the behavior of necessary contemplation afterwards in which I go through my impressions during the day and use that information to learn.

This explanation also sheds some light as to how people can have high verbal comprehension and performance index while not having good processing speed. Processing speed if low hampers performance index to some degree but less when it comes to verbal skills.

Some thoughts of mine.. I've had periods where my visual processing speed has been extremely high which during the time made me able to react much faster to people and my surrounding.
I think that having a balanced profile allows us to find our level of function easier but mine fluctuate a lot!

Recently been thinking about my approach to life and how it coalesce with testing scores..

I'm someone who has difficulties functioning in certain areas.. I seem to be better at randomly jostling around looking for "clues" or details that I need? I think of myself as unable to attend a university because of my poor performance in school subjects that are associated with writing and reading.. So I've been thinking about this and trying to adapt to my circumstance..

I wonder what my weakness is and what it is that makes me unable to do what would be more successful in a modern society. I'm not successful at all it would seem but I work hard every day to achieve something.

Similar to what other people talked about with ADHD it's like I have to work twice as hard but get half the result and I want to question why this is..

I believe results from the WAIS-test is more important then tests of executive functions when it comes to predicting success but the executive tests tells me more about how my process works? In what way am I attending to information well?

I've done TMT B for example online and recieved a score of 7/10 people.. That indicates a good executive function but when I tested my verbal flexibility with a psychologist i recieved a bottom result.. 1/10 I would say.. So one question is if executive flexibility is one thing or is dependent on different areas of the brain..

I do a massive amount of thinking and real life excursions because I don't think I am executively disabled, at least not in a standard sense so there are a lot of things I can do "visually". I have no problem planing a route or finding new patterns in movement. I think this is correct because of my high score in spatial working memory which is a good indicator of executive function. This with the TMT B result indicates I do well with visual orientation. I also don't have problems with visual computer games that I play..

Verbally I was thinking there might be something to my low score. Mostly I've been trying to imagine what someone with poor verbal flexibility would be able to say or interact with. I wonder if there is any truth to my poor result because I've been finding that I can have success even though my poor results have led me to believe I am useless..

A question for Aeh would be how I detect poor verbal flexibility as measured by the D-kefs verbal fluency collection. A question is also why executive functions matter on a practical level. One psychologist said it was decision making? Is it the speed at which we make new decision based either one verbal or visual information? "New choices" with which we direct out behavior?

I think that doing an IQ-test is not very reliant on Executive functions and I've read about it that the correlations between D-kefs and Wechsler subtests is in the 0.20 range if not lower.

The interesting thing is that I believe in IQ-testing a lot, to the degree that it's a certainty of ability in tasks. I had a poor coding result and I've been analyzing why that could be. There are multiple things that you need to be good at to be a "fast coder"..

Anyhow, having a executive detriment slows down coding or more generally, "the speed with which you accomplish something" and in the coding test they estimate how many digit/symbols you can finish within a short time frame.. I believe this to be a good estimate of how fast you progress with tasks.. What do you think Aeh?

The question that I've been pondering from the beginning is if the full scale IQ score is most important or if the CPI/GAI rule is relevant. The rule is that is you have to much variation in your profile the full scale IQ doesn't accurately represent your actual ability. A question would be if most my GAI scores are in the 120-130 range and coding is in the 80 range. Hmm.. I think the rule applies. Is this correct?

When I look at my real life pattern of verbal interaction I'm a person that doesn't answer and take my time to ponder the conundrum.. This would be a description of someone with low verbal processing speed but high verbal logical ability. I spend hours every day after I've come home analyzing thoughts and ideas I've picked up during the day, it seems there is endless learning..

It's not entirely accurate.. Executive functions are used to make new knowledge, stuff that I already know aren't a problem, i have enough verbal fluency for that (average).. I believe that the definition of "slow but deep" applies to me. Some people prefer quick surface interaction while I want accurate and to the point interaction, Quality of quantity I've said at some times..

Anyone else ponders this way?

I think the accurate description is "slow but accurate".. Takes time to develop ideas but they are very good when they are! This is because logical tests such a similarities measure the accuracy of you verbal thinking or "verbal logical reasoning" while coding assess speed of completion.. My low coding, the doctor claimed was due to poor executive functioning which means that my process of making a decision is really slow but since I'm very intelligent I make accurate conclusions about things.. I just can't wrap my head around the executive limitations based on how the test measures it..

You are asked to name one piece of fruit and then "switch" to a piece of furniture. Where does this process show up in real life? I think I tend to stick to one topic for a long time based in task itself.. The test assesses how many times you can switch and how many items you get accurately. I failed miserably at both. Does this test have anything to do with intelligence? Why do we use this test in the first place? What is executive verbal flexibility?