Wechsler Intelligence Scale for Children Instrument Assessment

The Wechsler Intelligence Scale for Children (WISC) is a test that is designed to evaluate intelligence in children of different ages. It was initially developed by David Wechsler and received a number of further improvements. David Wechsler is a world-renowned Romanian-American psychologist who significantly contributed to the development of psychological methods and theoretical models.

His contribution was particularly noticeable in the field of intelligence assessment for both children and adults. As already mentioned, WISC was first introduced in 1949. Therefore, it was edited and adjusted in order to comply with the most recent rediscoveries in the field and to compensate for the Flynn effect. The second edition was published in 1974, the third in 1991, and the fourth edition was introduced in 2003. Each of these revisions provided a number of new methods and approaches. The most recent edition of WISC was published in 2014 and is broadly utilized to date. The price for the instrument varies from $1,350 to $1,475, depending on the package and format.

Testing Kit

The testing kit is designed to provide needed instruments to assess intelligence in children between 6 years and 16 years 11 months of age. The kit consists of a number of components, including Technical and Interpretive Manual, three Stimulus Books, two Response Booklets, forms needed for recordings, scoring keys, and scoring templates (Wechsler, 2017). It also contains Wechsler Standard Block Design Set and cancellation Scoring Template. These components should be sufficient to conduct intelligence assessments in children according to the WISC frameworks.

Norming Sample

The norming sample for the WISC was based on 2,200 children. The sample was designed to accurately reflect the demography and achieve consistent and reliable results. Therefore, 11 age groups from 6 years to 16 years 11 months were included. Males and females were equally represented in the norming sample, and hence the study was balanced with respect to gender. The sampling method also focused on representing diverse ethnic and racial groups.

Hence, the norming sample was adjusted in accordance with 2012 US census data. Critical information regarding race and ethnicity was used, as well as data on the geographic spread of participants. A similar study in Canada involved fewer participants, with only 880 children tested. The sample was also designed in a way that reflects gender, ethnicity, race, and regional diversity. However, some sources state that the Canadian norming sample was too small to provide reliable results (Watkins et al., 2017). Overall, the sampling method is effective in terms of adequately representing diversity in society.

Purpose of the Instrument

The WISC-V is an important instrument that is normally used for two primary purposes. First, it may provide valuable data regarding the intelligence levels of a particular individual. Second, it may be utilized as a clinical tool in order to diagnose diverse intelligence-related disorders (Weiss, 2019). The first purpose of the WISC is usually utilized by school psychologists in order to assess discrepancies between the intelligence and performance of a child. It may be essential in terms of identifying the origin of the poor performance of a student. High discrepancies between performance and intelligence may indicate that the child is capable of performing better but is not willing to. Therefore, further actions should be taken in order to motivate the child.

The second use of WISC-V is broadly utilized in clinical practice. The instrument may help in diagnosing such disorders as attention-deficit hyperactivity disorder (ADHD) or learning disabilities. It may be challenging to diagnose ADHD in children as some symptoms may be interpreted as relatively normal behavior. Therefore, WISC-V frameworks play a significant role in identifying and assessing such disorders. The instrument is also highly effective as it offers a wide variety of scoring. In some cases, the final intelligence score is not as important as interim scores. It may be possible to diagnose learning disabilities or intelligence-related disorders by comparing primary index scores, ancillary index scores, and complementary index scores. Hence, the WISC-V represents a valuable tool that can be used.

Qualification Requirements

The WISC-V is a relatively complicated testing tool that requires high professional qualification. Even though the WISC frameworks offer sufficient methods and techniques, it may be challenging to assess intelligence accurately and comprehensively (Weiss et al., 2019). Therefore, qualification requirements include a high level of knowledge and skills related to test interpretation. In order to ensure that the test interpreter has sufficient skills, a number of requirements were developed. There are two alternative qualification requirements that may indicate a sufficient level of expertise.

First, an individual with a doctorate degree in psychology and education may use the testing instrument. In some cases, a doctorate degree in a closely related field that involves training in ethics, scoring, and clinical assessment evaluation may also be sufficient. Second, an individual with a membership certification in such organizations as APA and NASP in a relevant area may use the assessment tool. In general, qualification requirements include sufficient knowledge and practical skills related to test interpretation and education regarding ethical administration. It may be vitally important not only to conduct the testing with accuracy but also in accordance with ethical frameworks.


As the WISC-V is broadly utilized not only to assess interrelation between student’s performance and intelligence but also as a clinical tool, it may be essential to achieve high reliability. Test results provided by the assessment instrument may play a considerable role in diagnosing diverse intelligence-related disorders. Therefore, reliability was thoroughly tested in accordance with the targeted population using the norming sample.

Moreover, reliability is closely linked with validity as high reliability is required for validity. Split-half coefficients were used and computed from the norming sample, which was designed to reflect the targeted population. Average results were close to the mean score, which may indicate high reliability of the WISC-V. Furthermore, alpha internal consistency estimates, as well as model-based estimates, have shown high reliability levels. Therefore, the WISC-V may be considered a reliable instrument that accurately assesses intelligence with minor distortion.


Unlike previous editions, the WISC-V utilized a five-factor model in order to interpret testing results. Therefore, it introduces a higher-order system in terms of factorial validity. Moreover, the five-factor model relies on 16 subtests, which also improves the validity of the WISC. However, in some cases, the fifth factor, which was added in the latest edition, is viewed as unreliable and hence, invalid. Some sources state that only the matrix reasoning subtest has a considerable influence on that factor (Canivez et al., 2018). Moreover, the fourth edition is considered to be more reliable and is supported by EFA and CFA (Canivez et al., 2017). Therefore, it may be highly beneficial to test the WISC-V validity depending on the targeted population, and further development may be required.

Score Types

The WISC-V relies on a wide variety of score types designed to assess intelligence comprehensively and introduce consistent results in diverse dimensions. Primary index scores include Verbal Comprehension Index (VCI), Visual-Spatial Index (VSI), Working Memory Index (WMI), Fluid Reasoning Index (FRI), and Processing Speed Index (PSI) (Johnson, 2018). The VCI scores consist of several subtests, such as finding similarities, defining words, and assessing general knowledge.

The VSI scores rely on block design and visual puzzles, which are conducted with a time limit and measures visual-spatial processing. During the WMI testing, children listen to sequences of numbers, which they need to repeat. It may also involve picture span tests and Letter-Number sequencing. The FRI scoring includes matrix reasoning, figure weights, picture concepts, and arithmetic tests. The PSI is designed to assess processing speeds by such subtests as coding, symbol search, and cancellation.

The fifth edition of the WISC also included five Ancillary Index Scores that were designed for clinical purposes. Ancillary Index Scores include Verbal (Expanded Crystallized) Index (VECI), Expanded Fluid Index (EFI), Quantitative Reasoning Index (QRI), Auditory Working Memory Index (AWMI), Nonverbal Index (NVI), General Ability Index (GAI), and Cognitive Proficiency Index (CPI). In some cases, three complementary index scales may be utilized in order to assess cognitive processes that may be linked to learning disabilities. These three scales include Naming Speed Index (NSI), Symbol Translation Index (STI), and Storage and Retrieval Index (SRI).

The Mean Score and the Standard Deviation

The Wechsler Intelligence Scale for Children is designed in a similar way to the Wechsler Adult Intelligence Scale. In both cases, the mean score is 100 and should be achieved on average by all participants (Mireles, 2016).

The mean score should reflect the most probable results of the test, whereas standard deviation is utilized to divide test results into groups. In the WISC-V, the standard deviation is 15, and it divides the test results into five major groups. The biggest group is from 85 to 115 points, which is an average result that should be achieved by approximately 65% of people. Below average intelligence may be indicated by results between 70 and 85. The WISC-V results below 70 points may indicate intellectual disabilities and may require particular attention. On average, that group should include less than 2,5% of people. There are also results that may indicate intelligence levels that are above average, which is between 115 and 130 points in WISC-V. Finally, individuals who scored more than 130 points display intelligence levels that are significantly higher than average and may be considered as a sign of genius.

Professional Judgement

The WISC-V is an essential tool that can be used to assess intelligence levels in children. It offers relatively flexible frameworks that may contribute to comprehensive assessments and provide reliable results.

Moreover, the WISC-V can be adjusted by appropriate norming samples in order to adequately reflect the intelligence levels of the targeted population. It can also be used as a clinical tool, which may identify intelligence-related disorders that are hard to diagnose. However, there are also some limitations linked with the use of the WISC-V. First, it requires relatively high qualification of a professional who conducts the testing. Second, testing results may not be consistent if the norming sample fails to reflect the population. Conclusively, even though there are several limitations, the WISC-V is a valuable tool that should be broadly utilized in practice.


Canivez, G. L., Watkins, M. W., & Dombrowski, S. C. (2017). Structural validity of the Wechsler Intelligence Scale for Children–Fifth Edition: Confirmatory factor analyses with the 16 primary and secondary subtests. Psychological Assessment, 29(4), 458–472. Web.

Canivez, G. L., Watkins, M. W., & McGill, R. J. (2018). Construct validity of the Wechsler Intelligence Scale for Children – fifth UK edition: Exploratory and confirmatory factor analyses of the 16 primary and secondary subtests. British Journal of Educational Psychology, 89(2), 195–224. Web.

Watkins, M. W., Dombrowski, S. C., & Canivez, G. L. (2017). Reliability and factorial validity of the Canadian Wechsler Intelligence Scale for Children–Fifth Edition. International Journal of School & Educational Psychology, 6(4), 252–265. Web.

Wechsler, D. (2017). Wisc-V. Pearson.

Weiss, L. G. (2019). Wisc-V: Clinical Use and Interpretation. Academic Press.

Weiss, L. G., Locke, V., Pan, T., Harris, J. G., Saklofske, D. H., & Prifitera, A. (2019). Wechsler Intelligence Scale for children—fifth edition. WISC-V, 129–195. Web.

YouTube. (2016). Overview of Wechsler Intelligence Tests. YouTube. Web.

YouTube. (2018). Intelligence Testing the Wisc V. YouTube. Web.

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1. PsychologyWriting. "Wechsler Intelligence Scale for Children Instrument Assessment." September 19, 2023. https://psychologywriting.com/wechsler-intelligence-scale-for-children-instrument-assessment/.


PsychologyWriting. "Wechsler Intelligence Scale for Children Instrument Assessment." September 19, 2023. https://psychologywriting.com/wechsler-intelligence-scale-for-children-instrument-assessment/.