Testing Question

[Anonymous]

Does anyone know reasons for a significant discrepancy between verbal and performance sections on the WISC? We have this issue and I'm trying to gather some preliminary ideas before we do further testing.

[Anonymous]

You should meet with the test provider. It could mean nothing or lots of things. For us it was an early indication of attention issues.

[Anonymous]

Us as well. Verbal was easy for our child so did incredibly well on that section. Performance took more patience, so lost focus and rushed just to get it over with. Eventually the two sections evened out. Also, was diagnosed with adhd. Could be result of some other issue, however.

[Anonymous]

Our tester told us that it was attributable in large part to DD being left handed. I have a few friends with left handed kids who had similar experiences.

[Anonymous]

How much do you consider significant? My daughter had a big difference in points, but percentile wise it was 97 vs 99.8; I can't get too worked up by that.

[Anonymous]

Anonymous wrote:How much do you consider significant? My daughter had a big difference in points, but percentile wise it was 97 vs 99.8; I can't get too worked up by that.

"Significant" should be used in its mathematical sense here. Under no definition is 99.8 vs 97 "significant." But yay for you and your child.

[Anonymous]

Should it be used in the mathematical sense? The writeup we got actually said it was a "significant" difference. I was just trying to make the point (probably poorly) that large point differences might not be that significant when viewed in context of the bigger picture. If a child is especially good on one portion does that mean there needs to be something wrong if they're not equally as good on another section? We've all met people who are very good verbally and not as good at math and vice versa.

[Anonymous]

We were told variations in scores are "significant" if they are two standard deviations apart.

[Anonymous]

"Significant" should be used in its mathematical sense here. Under no definition is 99.8 vs 97 "significant." But yay for you and your child.

There is no such thing as mathematical significance. It's called statistical significance and you probably want to read up on it to really understand the scores.

[Anonymous]

google : high verbal IQ/ low processing speed and read all the information and research posted by Davidson Young Gifted Center and others. Basically, the skinny on the WIPPSI and WISC is that, though the Verbal,Matrix reasoning,Perceptual reasoning are good indicators of giftedness, processing speed is the poorest measure( poorest indicator) at measuring giftedness to the point that it confounds the overall score. If a child tests more than 2 STD apart on any subset the results cannot be interpreted, and SHOULD NOT be averaged, which is what the test instructions say to do.

Also,I read that as the WISC is not a test specifically designed to identify giftedness, but rather to identify problems at the lower end of IQ scale, it is more appropriate to look at the score in context with someone who cannot follow instructions or is doing poorly in school, despite high IQ overall. If you look at scores below, you will see that the average person, with an average IQ has very little discrepancy between Verbal IQ and Performance. Gifted people, on the other hand, often have a wide variance. This is because they score significantly higher on other parts of the WISC, whereas average people do not.

Average scores Gifted Scores


Verbal Comprehension 104 Verbal Comprehension 145

Processing speed 100 Processing speed 100


What you will never see is this: Verbal comprehension: 98 / processing speed 145

[Anonymous]

First point: the absolute value of each score is as important as the size of the discrepancy. A pattern with two divergent but very high scores (e.g., VCI=155, PRI=128) is more common, and less meaningful, than the same pattern 30 points lower. This is because there is generally more variation at the upper end of the scale (it's uncommon to be highly gifted at everything) and because a score at the 97th percentile isn't really a handicap.

Second point: it is true that children with ADHD often have more trouble with the PRI than the VCI. One of the PRI tests is timed, with bonus points for speed, so a slow/distracted worker suffers (although at young ages, a kid who works slowly but gets everything right will still get a very high score). Also, all three of the PRI tests require pretty good executive functioning (planning ahead, seeing the big picture, choosing the best answer from several possibilities, using lots of working memory).

Third point: on the WISC, handedness should make no difference at all on the PRI. You can assemble the blocks with your right hand, your left hand, or your feet, whatever works for you. The other two tests are motor-free - just looking at pictures and reasoning. Unless you're saying that left-handed children have stronger right hemispheres in the brain it makes no sense. And even then it makes no sense. The only subtest on the entire test where handedness could matter is Coding, and that goes onto the Processing Speed Index, not the Perceptual Reasoning Index. On the older WISC-III Coding did load on the Performance Scale, but it was one test out of six so it still wouldn't make a big difference overall.

Last point, while it is uncommon to see a very high PSI and lower/average VCI and PRI, it's not impossible. It's just that those kids aren't gifted.

[Anonymous]

I disagree with the above PP who said that, " a child who works slowly, but diligently and gets all correct will still get a very high score" . This is not true with the coding subset of the processing speed portion of the WISC IV. A child who is a perfectionist, as many gifted are, and who works carefully, thoughtfully and deliberatively will get a relatively "low" score compared with their other subtests that test their knowledge and reasoning ability with less emphasis on speed. While it is true that consecutive wrong answers stop the testee and fix the score, a child given to perfectionism ( as many gifted children are) may choose to work slowly and carefully, may choose to go back and change an answer if in later prompts they recognize a pattern that their working memory( also high) tells them that they coded wrong ten answers ago so they go back and change the answer....doubly so if they are a young child with developing fine motor and growing testing experience, such that they do not realize that correcting a wrong answer by going over it over and over again with a pencil, though effective in correcting, takes significant time and slows them down. Coding is a timed test and the gifted child who is a perfectionist often takes MORE time, not less on this test , and the results then confound there overall IQ score. Note the research on this below:


http://www.gifteddevelopment.com/PDF_files/NewWISC.pdf

For this reason, organizations that work with the gifted , use the GAI as an indicator of giftedness. ( the calculation of GAI is outlined in the above ref'd research paper)

[Anonymous]

Anonymous wrote:I disagree with the above PP who said that, " a child who works slowly, but diligently and gets all correct will still get a very high score" . This is not true with the coding subset of the processing speed portion of the WISC IV. A child who is a perfectionist, as many gifted are, and who works carefully, thoughtfully and deliberatively will get a relatively "low" score compared with their other subtests that test their knowledge and reasoning ability with less emphasis on speed. While it is true that consecutive wrong answers stop the testee and fix the score, a child given to perfectionism ( as many gifted children are) may choose to work slowly and carefully, may choose to go back and change an answer if in later prompts they recognize a pattern that their working memory( also high) tells them that they coded wrong ten answers ago so they go back and change the answer....doubly so if they are a young child with developing fine motor and growing testing experience, such that they do not realize that correcting a wrong answer by going over it over and over again with a pencil, though effective in correcting, takes significant time and slows them down. Coding is a timed test and the gifted child who is a perfectionist often takes MORE time, not less on this test , and the results then confound there overall IQ score. Note the research on this below:


http://www.gifteddevelopment.com/PDF_files/NewWISC.pdf

For this reason, organizations that work with the gifted , use the GAI as an indicator of giftedness. ( the calculation of GAI is outlined in the above ref'd research paper)

I'm the PP you were quoting, and the quote is from a paragraph about the Perceptual Reasoning Index (specifically about the Block Design subtest). Coding is on a different Index (Processing Speed). A VERY slow worker may not finish the designs in time to get credit but that's very unusual - the time limit is generous. My point was that a slow worker won't get bonus points, but at young ages that doesn't really matter for the final score.

You should also know that Coding is not a get-five-worng-and-then-we-stop subtest. It is a flat 2-minute time limit, with a point for every correct response. It's true that a perfectionistic kid will get a lower score. The GAI is used not globally for gifted kids, but for any kid where the VCI and PRI are significantly higher than working memory and/or processing speed.

[Anonymous]

New poster here. Can I suggest that the two PPs who want to discuss what certain scores may or may not say about giftedness please take your discussion to another thread? OP's question was just about a disparity between scores, and not about GT issues. Thanks.

[Anonymous]

We had a big difference between our verbal and performance (verbal low, performance high) Further testing showed that my son had issues with auditory processing and needed help with language as related to spelling and reading. He is now a much better reader, just okay with spelling and writing but we found out early enough to do something about it.