GT-World Testing FAQ

Frequently Asked Questions about ... The Wechsler Intelligence Scale for Children (WISC)

Note: the information contained in this FAQ is not intended to be professional psychological advice, in fact this FAQ was compiled from various Internet sources. It is a summary of information gathered by parents, for parents, of gifted children. 

The Wechsler Intelligence Scale for Children (WISC)

Many psychologists use a Wechsler Intelligence Scale for Children (WISC) to identify learning disabilities. The WISC-R (R=Revised) is an intelligence test that can be administered only by a licensed psychologist or tester. The scores may be interpreted in several different ways by specialists and nonspecialists alike who understand the significance of the numbers. A WISC score is derived from the scaled combination of two sets of subtests, Verbal and Performance. Each of these two categories has its own total, which is derived from the scaled combination of 6 subtest scores. Symbol Search -- processing speed without the motor component -- was recently added to the WISC-III Performance section. Additional differences between the WISC-R and WISC-III are described in the bibliographic citation from the ERIC Clearinghouse on Assessment and Evaluation at the end of this FAQ. [From ERIC: GT LD Test-FAQ

Unfortunately, many psychologists also use the WISC to identify gifted children. This is unfortunate because the test was not designed for such use.

"He rejected most attempts that I made to add easy or hard items to the WISC-R saying firmly, 'My scales are meant for people with average or near-average intelligence, clinical patients who score between 70 and 130.'" "They are clinical tests." When I reminded him that psychologists commonly use his scales for the extremes, and want to make distinctions with the 'below 70' and 'above 130' groups, he answered, "Then that is their misfortune. It's not what I tell them to do, and it's not what a good clinician ought to do. They should know better." -- Intelligent testing with the WISC-III by Alan S. Kaufman, New York : Wiley, ©1994

Newer versions of the Wechsler tests, the WISC-IV and WPPSI-III, reach mildly into the gifted ranges, but are still not intended for use with highly, exceptionally or profoundly gifted kids. In Assessment of Children WISC-IV and WPPSI-III Supplement, Sattler and Dumont state that the WISC is not a good measure for children scoring outside of 3 deviations from the mean. An average subtest score of 14 or 15 is 2 standard deviations outside the mean, an average subtest score of 16 or 17 is 3 standard deviations outside the mean. Sattler and Dumont do not discuss the use of the test above those levels at all

"A flat profile of scores in the 14 to 16 range [indicates] that the child is gifted intellectually and may profit from instruction that capitalizes on the child's exceptional intellectual skills." -- Assessment of Children WISC-IV and WPPSI-III Supplement by Jerome M. Sattler and Ron Dumont

For more information on the ceiling effects of the WISC tests on gifted children, visit Hoagies' Gifted Education Page on Testing and Measurement and read "Don't Throw Away the Old Binet" by Linda Silverman and Kathi Kearney, and "Current Use of the Stanford Binet, Form L-M" by Barbara Gilman and Annette Revel.

Notes: Subtests in square brackets are optional. Verbal subtests are those with semantic items, performance subtests are those with pictorial items. All verbal subtests require that the child interpret meaning from the English language in some way. Performance subtests could be given and responded to without using language at all, merely by pointing at examples and available materials, for example. 

Verbal Subtests 

Information - (1) Fund of general knowledge; (2) Factual knowledge, long-term memory, recall; (3) This measures how much general information the child has learned from school and at home. 

Similarities - (1) Verbal abstract reasoning; (2) Abstract reasoning, verbal categories and concepts; (3) This measures the child's ability to think abstractly. The child decides how things are different or alike. 

Arithmetic - (1) Numerical reasoning, attention and short-term memory for meaningful information; (2) Attention and concentration, numerical reasoning; (3) This is not pencil-and-paper arithmetic. Rather it measures verbal mathematical reasoning skills by giving the child oral problems to solve. 

Vocabulary - (1) Knowledge of word meanings; (2) Language development, word knowledge, verbal fluency; (3) The child explains that a word means by defining or describing what it does. The dictionary definition is not the only acceptable answer. 

Comprehension - (1) Social comprehension and judgment; (2) Social and practical judgment, common sense; (3) This measures how well your child can think abstractly and understand concepts 

[Digit Span] - (1) Short-term auditory memory for non-meaningful information; (2) Short-term auditory memory, concentration; (3) This measures a child's ability to remember a sequence of numbers (both backwards and forwards). This sub-test is optional and does not have to be included in your child's assessment 

Performance Subtests 

Picture Completion - (1) Attention to visual detail; (2) Alertness to detail, visual discrimination; (3) The child looks at pictures and tells the examiner what part is missing 

Coding - (1) Visual-motor skills, processing speed; (2) Visual-motor coordination, speed, concentration; (3) This section measures a child's ability to decipher a code and copy the correct symbols in a controlled period of time. 

Picture Arrangement - (1) Attention to visual detail, sequential reasoning; (2) Planning, social logical thinking knowledge; (3) This requires a child to put pictures in order so that the story they tell makes sense. It measures their ability to create the whole from its parts. 

Block Design - (1) Visual abstract ability; (2) Spatial analysis, abstract visual problem-solving; (3) Unlike picture arrangement, where the child is given the parts and makes up the whole, this test measures the child's ability to look at the whole first, then break it into parts, and finally to reconstruct the whole. It provides blocks and pictures, and the child must put the blocks together to re-create what's in the picture of the blocks 

Object Assembly - (1) Part-whole reasoning; (2) Visual analysis and construction of objects; (3) The child is given puzzle parts and must complete the puzzle. It measures a child's ability to make a whole out of its parts. 

[Symbol Search] - (2) Visual-motor quickness, concentration, persistence (note: new with WISC III) 

[Mazes] - (1) Graphomotor planning, visual-motor coordination and speed; (2) Fine motor coordination, planning, following directions; (3) The child has to find the way out of a maze by using a pencil. Performance is also based on time. 

Information compiled from: 

  1. ERIC: GT LD Test-FAQ
  2. LD Online: Understanding Tests and Measurements
  3. Parent Soup: Psychological Evaluation

Specific Test Information

This page last updated on 12/15/99 by Carolyn K. Please submit all questions and answers directly to Carolyn. Thank you. 
Copyright ©1999 by Carolyn K. 
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