Wechsler Intelligence Scale for Children (WISC – IV)

This is a whisk, not a WISC!

This is a whisk, not a WISC!

The Wechsler Intelligence Scale for Children is referred to as the WISC. (No, not that type of whisk!) The WISC consists of a series of short sub tests that are used to assess cognitive ability. Usually the scores are consistent across the lifespan.

What is a WISC?

The WISC-IV (Wechsler Intelligence Scale for Children- Fourth Edition) is an individually administered clinical instrument for assessing cognitive ability of children between the ages of 6 years through to 16 years 11 months. The test provides subtest and composite scores which represent intellectual functioning in specific cognitive domains as well as a composite score which represents general intellectual ability. The WISC-IV takes from 1 ½ to 2 hours to complete. The report and scoring of results takes a qualified psychologist from 4 to 8 hours to complete.

Why might a teacher recommend a WISC Report?

A classroom teacher may recommend a WISC if there are inconsistencies in a child’s performance or a child is struggling to comprehend grade appropriate tasks.  The WISC assesses a student’s learning, potential and ability.  The WISC should be used as a part of a comprehensive psycho educational assessment. Often psychologists will use the WISC and an achievement based test, such as the WIAT–II (Wechsler Individual Achievement Test—Second Edition) to fully assess an individual’s learning profile.

Key Benefits of a WISC Assessment

The main benefits include:

  • Early identification of reading & learning issues;
  • Useful in identifying learning disabilities;
  • Understanding of an individual’s learning profile;
  • Identification of gifted children;
  • The assessment also helps Schools make appropriate; accommodations and develop learning plans for individual students;
  • The ability to determine learning processes, which include both strengths and weaknesses and the impact that they might have on individual student performance.

How to make sense of a WISC report?

The WISC allows the psychologist to identify learning patterns. It has four main components that are referred to as Indexes. These are called the Verbal Comprehension Index, the Perceptual Reasoning Index, the Working Memory Index and the Processing Speed Index.  Within each of these four domains are a variety of subtests that form the index score.

  1. The Verbal Comprehension Score emphasises crystallised intelligence and knowledge application.
  2. The Perceptual Reasoning Scores related to fluid reasoning/ intelligence or the ability to learn new information.
  3. The Working Memory Score assess auditory short term memory and retrieval.
  4. The Processing Speed Index had a emphasis on mental quickness and task performance with focused concentration and attention.

Verbal Comprehension Index

Verbal Comprehension Index (VCI) – measures verbal concept formation, verbal reasoning, and knowledge acquired from one’s environment. The subtests include:

  • Vocabulary: word knowledge and retrieval
  • Similarities: Verbal concepts and reasoning
  • Comprehension: social knowledge and awareness
  • Information*:  recall of verbally-encoded, factual  information
  • Word Reasoning*: general reasoning ability

Perceptual Reasoning Index

Perceptual Reasoning Index (PRI) – measures perceptual and fluid reasoning, spatial processing, and visual-motor integration.  The sub tests include:

  • Block Design:  visual spatial reasoning and visual-constructional ability.
  • Matrix Reasoning:  non verbal reasoning and concept formation.
  • Picture Concepts:  abstract, categorical reasoning.
  • Picture Completion:* attention to visual detail.

Working Memory Index

Working Memory Index (WMI) – requires working memory processes to manipulate orally presented verbal sequences. Or to simply recall orally presented sequential information. The sub tests include:

  • Digit Span – Digits Forward: Auditory short-term memory.
  • Digit Span – Digits Backward:  Auditory working memory.
  • Letter-Number Sequencing:  shorter string lengths indicate memory – longer reflect auditory processing.
  • Arithmetic:* auditory short-term memory, auditory working memory, fact retrieval.

Processing Speed Index

Processing Speed Index (PSI) – requires visual perception and organisation, visual scanning, and the ability to use hands and eyes together efficiently. The attention factor is two minutes. The sub tests include:

  • Coding:  speed and accuracy (fine motor control); incidental learning.
  • Symbol Search:  mental processing speed and accuracy.
  • Cancellation*:  processing speed, visual selective attention, visual neglect, vigilance.

*supplemental (not included in full scale IQ score)

Reference: Wechsler, D. (2003). WISC – IV Australian Administration and Scoring Manual. Harcourt Assessment.

  1. Kim Considine10-03-2010

    Do you have the range of scores that would be considered low, average, above average, etc… for the WISC_IV?

  2. rt12-04-2010

    lower averge: 85 – 99
    below average: 70 – 84
    borderline low : 55 – 69
    low: lower than 55

  3. tracey deegan12-18-2010

    My son has been having increasing problems with school. He has always taken an exceptional amout of time doing homework, esp. math. He took the wisc-iv test and did exceptional in all areas except the psi. His percent rank is 2!!! I have been explaining to the school he has always had difficulties…they say he is just “defiant”. Can I please have an explanation as to how this can affect my child? Should other testing be done? It takes him hours to do the work most do in 20 mins. Neither he or I can take any more 2 hr home work marathons. Any suggestions??? Please!!!

  4. Crystal02-18-2011

    Would this test be used for a student with OCD? Obsessive Compulsive Disorder?

  5. Deborah Jepsen02-18-2011

    The WISC-IV is a cognitive assessment. It basically assesses general intelligence and learning potential. You need a personality assessment for OCD, or a clinical interview with a psychologist.

  6. Deborah Jepsen02-18-2011

    It might be worth getting him tested with an achievement test, such as a WIAT. That test will explore his ability in reading, writing and maths. If his processing speed is low, it might be a handwriting speed (or pencil grip) issue, or he may simply process things slowly.
    The following subtests contribute to the PSI:
    • Coding – measures speed and accuracy of visual-motor coordination, speed of mental operation, attention skills, visual acuity, visual scanning and tracking, short-term memory, cognitive flexibility, hand writing speed and, possibly, motivation.
    • Symbol Search – measures perceptual discrimination, speed and accuracy, attention and concentration, short-term memory, and cognitive flexibility.

    You might want to look at the index scores to gain more insight.

  7. Laura03-05-2011

    Tracey, I’ve never written a comment on a blog or comment place like this before, but I feel very compelled to do so, since I just came back from a meeting at school, where I was told my son is 7, in this regard. Everthing else is much, much higher (so we’re very blessed), BUT we’re completely in your boat about NO MORE HOMEWORK MARATHONS (4+ hours/night, 8+ on weekends). I don’t know much, but will begin learning. Our school & state now recognize this as a ‘disability’, and my son will receive attention that he needs. These kids have a ‘disability’ in that they process slow. They are not dumb. I urge you to work with the school. We are just getting started today. My heart goes out to you.

  8. V Greybe03-13-2011

    My son scored extremely bad and was told that he had a very below average IQ was we are told to take him to a remedial school – we only did the test as he was experiencing panic attacks when he went to school – his teachers from grd0 to grd 3 are shocked and told us not remove him.

  9. Kerry Page05-11-2011

    My son is currently in Year 8 and I have been requesting physchological testing for years due to his slow learning in reading and spelling plus dyslexia being in the family – finally upon attending high school the testing got done – using mainly WISC – hoorah finally diagnosed as dyslexic and the school can now put appropriate processes in place to assist his learning.

    Please do not leave your childs learning too late, insist on testing even is you have to tie yourself to the school fence because I wish I had done that – maybe if I had my son who is currently 13 would have the reading and spelling ability closer to his age rather than that of a 10 year old

  10. lilla hoey06-10-2011

    my 6yr old has just had the WISC test done and scored in the top 10%. Does this mean she is gifted or bright?

  11. Deborah Jepsen06-20-2011

    It means she is above average but not gifted. The lowest IQ typically associated with giftedness is 130; this score or higher is seen in only about 2.5% of children. However, the good news is you don’t need to be a psychologist to assess her as ‘bright’. 🙂


  12. Deborah Jepsen06-20-2011

    @V Greybe
    I would be wary of taking any drastic action based on a single cognitive assessment. It may be worth seeking a second opinion from an Educational Psychologist. In addition, I would consider seeing a Clinical Child Psychologist and/or a Paediatric Psychiatrist regarding the anxiety issue.


  13. klc06-22-2011

    I have two questions and I really hope someone can help me. What does it mean if a child (6 yrs old) is tested and comes out having an average score on verbal comprehension and perceptual reasoning, but scores very high on working memory and processing speed?
    Is she gifted or not? Obviously the two average scores pulled down her other scores, but I’m just wondering what this means.

    The psychologist who did the test claimed she is totally average, will “never be a journalist”, and can be happy if she gets “B’s” for the rest of her school career. And if she gets A’s it’s because she is very determined.

    This is NOT how I experience my daughter. Can anyone help me figure this out? I’m very confused.

    The other question: Can being bilingual cause a child to score lower on the verbal comprehension?

    Thanks so much for any help!

  14. Melissa06-26-2011

    My daughter is 5 (6 in January), and has had many assessments done, including an IQ test (she was 4 at the time) and her result was low average, but with adult guidance she can be pushed into the normal range, and she has since been diagnosed with autism. She is slow in learning. I was talking to some people yesterday, and they suggested that we request a WISC from the school. What would the recommendation be. We are planning on changing schools next year anyway, as I am not satisfied with the way things have gone this year. The only reason she is still where she is, is because 1. I dont want to keep changing things, and 2. she has a marvellous teacher who is willing to do the hard yards with her (any other teacher would have put her in the too hard basket). So, should I just let things go this year as they are, and once she is settled in her new school, request it then?

    I am one confused mama

  15. nunyabiznez07-18-2011

    @klc – no one can or should make a judgement of that nature based on scores of this kind and a child of your child’s age. if your child wants to be a writer now, encourage him/her, but let her change her mind… being ‘average’ is not a bad thing and scoring ‘average’ scores on a test of this nature doesn’t accurately reflect what your child can achieve, plain and simple.

  16. louisa10-17-2011

    @kic – my 8 year old daughter has just done the test an also got low average in verbal comprehension, average in perceptual reasoning and superior in working memory and processing speed. The average marks pulled down her overall IQ result and they did tell me it would effect her school results but with help she could still reach her potential. They said she was a visual learner rather than verbal. I’m not too concerned, of course I would like her to bring home results that she is capable of but I also don’t want to put pressure on her as they said she was quite anxious about making mistakes. They also said when she is actually doing subjects that she really enjoys there will be no stopping her…good luck

  17. David10-20-2011

    My son scored low on block design on the WISC IV (standard score of 7) but scored average on Matrix Reasoning (10) and high average on picture concepts (13) and Picture completion (12) for a total score of 100 on performance part of the IQ. He has had some issues with visual motor integration when the OT tested him and scored in the low average range (85). I believe I read somewhere that visual motor integration is measured by the performance IQ) and I am just wondering is the visual motor integration the sub test that correlates with just block design or all the sub tests on the performance IQ. His score would make sense if it was just on block design as he scored low on this as well as his VMI. I should also mention that he was just diagnosed with ADHD and now has been placed on medication.

  18. cc_texas10-23-2011

    We just got our results back for my son. He scored at above 99.9th percentile on his Wechsler test. In the report, the psychologist mentioned that he is just as at risk as a child that’s at the 1st percentile because he will need help getting through school and staying challenged. The overall test also included the Woodcock-Johnson test which shows that he places at 6th grade across the board (verbal, spelling, math etc). But he’s only in 1st grade, just turned 7 years old. I am at a loss as to what I should or can do with him. There is no way I can put him in a classroom full of 12 year olds. Anyone else here that has had similar experience with their child and can share some thoughts?

  19. ks11-16-2011

    my 6 year old son scored top 2% on wisc iv test. I am told he is gifted. I am interested in any recommended strategies for his development. Is acceleration considered the way to go. He is in kindergarten and am unsure if emotionally it will be too much for him to be singled out by doing extra work/ higher level work.

  20. Morag12-07-2011

    My daughter (year 8) has had this test but there is a vast disparity in her results. She did exceptionally well in verbal reasoning and perceptual reasoning – above and average respectively, but her working memory was below average 4%. Also in the final test, her processing speed she gained 100% in the accuracy of both tests, but… one test she had average results and the other subtest she got below average. I would love to know what this means. It is possible that she is a high functioning autistic, although in the past she has been diagnosed with dyslexia and dyspraxia. I’m at a bit of a loss as to what the results mean. Why such a stark disparity?

  21. Karen12-22-2011

    My son scored a 141. Would that be considered “gifted”?

  22. Gemma12-29-2011


    My daughter sat the WISC IV when she was 6 and scored 156 (and the psychiatrist thought she could get higher but was so tired after 31/2 hours testing she was losing focus).

    We took her to be assessed as I believed some behavioural issues as school were related to her ability as she had always seemed exceptional on occasions to me (and completely daft in others!)

    My understanding is this is really high (>99.9%) yet now she is 9 she is doing well in school (is usually top or 2nd in her year) but is not standing out and does not seem to have a great passion for learning.

    She seems happy, although she sometimes gets frustrated that her peers don’t have the same level of emotional maturity (she never seems frustrated by them having less academic/intellectual ability – she just expects that) and she enjoys lots of performing arts too.

    I worry sometimes that she is just coasting, she does the work necessary to come at the top, but nothing more, and I just don’t know whether I am doing her a disservice in not pushing her to exceptional achievement, or if it would be worse to push her.

    Are there many cases of very highly scoring children leading pretty average lives and being happy about it – or will they look back one day and think they wasted their opportunities?



  23. cornfuzzled01-19-2012

    My 7 1/2 year old daughter was given the WISC-IV Short Form to help determine whether she qualified for Gifted services from our school district. She does qualify but I’m still a little confused by the report we were given.

    Verbal Comprehension:
    Similarities 13
    Vocabulary 14
    Comprehension 12

    Perceptual Reasoning:
    Block Design 12
    Picture Concepts 13
    Matrix Reasoning 16

    Verbal Comprehension
    Composite Score: 138
    Percentile: 99
    Confidence Interval 95%: 129 – 142

    Perceptual Reasoning
    Composite Score: 123
    Percentile: 94
    Confidence Interval 95%: 114 – 129

    General Ability Index
    Composite Score: 136 (IS THIS HER IQ?)
    Percentile: 99
    Confidence Interval 95%: 129 – 140

    Interpreted Intellectual Ability: Very Superior Range

    {Your child} scored within the Very Superior range of cognitive functioning on the WISC-IV Short Form, with verbal skills within the Very Superior range and nonverbal skills within the Superior range. She demonstrated strengths in concrete verbal reasoning and vocabulary development. A relative weakness was noted in practical social judgment (although still within the Average range for her age). In nonverbal subtests, she demonstrated a significant strength in abstract reasoning, a strength in conceptual reasoning, and a relative weakness in visual-motor coordination (although still within the Average range for her age).

    Can you please explain the “relative weakness” things and which test listed above they refer to? Obviously, my child is more intelligent than I am but I’d like to try to understand her results more fully. I don’t feel I can advocate for her unless I understand what this means exactly.

    Thank you!

  24. sandy01-21-2012

    My son is borderline in perceptual reasoning index,working memory index, and full scale IQ. What does this mean?
    He has difficulty in Math.
    What are the index scores?