WISC-IV subtest score interpretation?

[LynnS6]

I posted a while ago that I was worried about ds' visual-spatial processing being much weaker than his other skills. I finally got the info back from the research study that ds is part of, and they've given me the scaled scores on the WISC-IV subtests they gave, but no interpretation. I'm not sure how the scores for the sub-tests correspond to the overall score.

They gave him the Block Design, Vocabulary, Information and Digit Span tests. He scored quite a bit lower in Block Design (7) than the other 3 (13). Since I don't know anything more about the WISC-IV and the subtests, I'm not able to interpret this.

Can anyone point me to a resource? Thanks!

(If it helps, my suspicion is that he's about the 90th percentile for most things. It's the difference in score between Block Design and the others that concerns me.)

[chiefmir]

I can give you some basic info on the scores you posted-  the visual spatial subtest scores will combine to give a Perceptual Reasoning Index score, which (in turn) contributes along with the other Index scores to the Full Scale IQ score.  Generally for school, a FSIQ of 130 and over is considered gifted, though there is room for individual interpretation of scores based on strengths/weaknesses etc.

The scaled score of 7 is equiv to a score at the 16th percentile and the subtests with a scaled score of 13 are equiv to scores at the 84th percentile.  ALL of the subtests that make up the PRI are visual spatial subtests, so I wouldn't worry about one particular subtest score unless it is a part of a pattern of other low scores (16th percentile is considered "borderline impaired" by most in the field) AND if there are functional deficits.  Otherwise, one low or lower score usually is irrelevant. 

Particularly in the case of the Block Design subtest, HOW the child failed the items that they got no points for (the subtest is discontinued after 3 scores of zero in a row) is important.  For example, a child could get zero points for the last 3 items they were given, but they might have gotten each one correct, but not before the time cut off.  If a child is still working on an item at the 60 second mark, for example, we usually let them finish rather than make them stop in the middle because it is upsetting to them and could affect their mood/other scores.  So, if a child got some wrong on the Block Design subtest due to speed, then there is no visual spatial problem- it is processing speed (how did your DS do on the Processing Speed Index?)

Hope some of that helps!

[ChristaN]

The few things I can tell you:

A scaled score of a 7 is the 16th percentile.  The block design subtest relies heavily on not only what it is testing (visual spatial ability/ability to rotate things in space), but also on speed.  A child with motor difficulties or anxiety or processing speed issues may do significantly worse on this section than the other two pieces of the PRI index, which it doesn't sound like he was given at all.

Of the other parts he was given, vocab and information, are 2/3 of the VCI index.  Scaled scores of 13 are at the 84th percentile.  Technically anything btwn 8-12 is considered average (1 standard deviation or less from the mean), so his scores fall just a bit outside of that range on both sides.

Digit span is 1/2 of the WMI index.  Again, that 13 is at the 84th percentile.

I guess that I'd like to see the PSI (processing speed) index given to see if the block design score was due to speed issues as well as the other two tests in the PRI (perceptual reasoning) index given to see if he really has issues with visual spatial stuff.

[LynnS6]

They didn't give the Processing Speed Test to him. This was for an ADHD research study where ds is a control, and so they only gave a few subtests  of the WISC. 84th percentile is about where I'd put ds in terms of skills. Above average, but well within the ability of most classrooms to handle him.

The question is: Given the discrepancy between the block design and the other 3 that they gave him, is it worth following up with educational testing of our own? What are the implications of either low visual spatial skills or low processing speed? (OK, maybe I need to take this over to Special Needs, but I know there are more parents here with experience with testing.)

[chiefmir]

Without any "reason" to be concerned about neuropsychological or psychoeducational functioning, I would definitely not recommend further testing at this point.  If there are overall concerns or specific concerns, that may warrant thoughts.  I would not put any level of concern into the lower block design subtest, particularly b/c it can be impacted by speed.  Also, one of the reasons that a real full battery of testing can take up to 7 hours to administer is because one low (or high) score in an area is essentially meaningless (IMO) and the whole idea is to look for a pattern of scores.

[ChristaN]

So, if I am reading this correctly, your child is not suspected of having ADHD, correct?
 

Originally Posted by LynnS6 

They didn't give the Processing Speed Test to him. This was for an ADHD research study where ds is a control, and so they only gave a few subtests  of the WISC. 84th percentile is about where I'd put ds in terms of skills. Above average, but well within the ability of most classrooms to handle him.

The question is: Given the discrepancy between the block design and the other 3 that they gave him, is it worth following up with educational testing of our own? What are the implications of either low visual spatial skills or low processing speed? (OK, maybe I need to take this over to Special Needs, but I know there are more parents here with experience with testing.)

I'm not as sure on impact of lower VS skills, but would venture to guess that might play out as a child who is less of an out of the box thinker and maybe weaker in higher level math that doesn't rely so much on arithmetic and memorization.

In regard to lower processing speed, both of my kids tested lower on processing speed than their other indeces of the WISC but for different reasons.  One is HG+ and 2e and, while her PSI score looked average, it wasn't related to her actually doing things slowly, but rather to her making huge numbers of errors (she has ADD).  I've had the adult version of the same IQ test given and my PSI was in the 99th.  This one kiddo of mine can beat me occassionally on timed games like Blink so I don't really think she is slow so much as error prone and lacking attention to detail.

My other child truly is slower than the rest of her abilities.  I can't call it true slow processing in that her PSI was average, but since her other scores were significantly higher (she, too is HG, but not really 2e), it is slow for her.  In her case, she is grade and subject accelerated and, in order to be placed where she belongs intellectually, she winds up either needing a little extra time occassionally to complete tests or she spends much longer on homework than other kids who process faster.  Her school is heavy on homework anyway, but I'd say that she takes longer than someone, say like me who whipped through stuff quickly.  She spends hours on homework quite frequently.  This might not work for many children who would get burned out.  The only thing that keeps her plugging away is that she is unusually motivated and directed in her career focus.
 

[LynnS6]

Christa -- you're right ds does not have ADHD. It's never been suspected, and the research study confirmed it. They were very thorough in their testing for ADHD, so I believe them. I know the Block Design alone doesn't show much,  but it confirms what I've observed about his overall visual spatial skills. He actively avoids anything to do with visual spatial reasoning. No puzzles (he can't do them), no tangrams, no games like TrafficJam, no legos.

Ds does not struggle academically, but there are certain times when I wonder. He scores relatively high (95th percentile) in math reasoning, but lower in math accuracy. He refuses to try any kind of music. He sometimes really bombs reading passages where he's supposed to extract information and I wonder if it's a processing speed issue. He's terrible at remembering details, but he's verbally quite quick in conversation.

I think for now, I'm not going to do anything. I'm going to keep this info in the back of my mind. I'm  not worried about what he's doing now. He's not got the scores to get into the gifted middle school, and honestly, I don't think he'd thrive there. He's remarkably unambitious about academic things. My concern is really for the future and whether not really knowing whether he's got an issue with either visual spatial stuff or processing speed is going to hurt him down the road.

So, it's the mixed picture of being really pretty good at some things and really not good at others that makes me wonder. If all it means is that he's not going to be an architect or civil engineer, I can handle that. If it means that he's going to become increasingly frustrated at school, that's not good.