The Wechsler Intelligence Scale for Children Fourth Edition - Essay Example

This paper reports on the WISC-IV an intelligence test for children. Within the scope of the paper the reliability, validity and history ofthe test are given. The research also gives a thorough understanding of the test so that a layman can understand some of its parameters. Within the scope of this paper, an understanding of how the test can be used in this researchers future practice will be given. Finally, the paper will explore future ways for the WISC-IV to be used. The Wechsler Intelligence Scale for Children Fourth Edition (WISC-IV) The Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) was chosen because it is a test for children ages 6 to 16. The children that I work with are ages 11-16 which make it an appropriate test. The first version of this test was published in 1949 and today it is the "most widely used individual intelligence test for children," (Hogan, 2005, p. 306) surpassing the Stanford Binet. Wechsler, like many others, had his own definition of intelligence that has always been a part of the various versions of the test he created. His definition of intelligence is: "The aggregate or global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment" (Hogan, p. 297). He also said that intelligence was more than a childs intellectual ability; it also concluded that "the capacity to do intellectual work is a necessary and important sign of general intelligence" (Wechsler, 1952, p. 12 as quoted in Hogan, p. 297). In other words, Wechsler understood that children had the capacity to think on their own and to develop intelligence in more than one way. Description of Test and History The original test was an extension of an adult test called the Wechsler-Bellevue test. It included three sub-sections that were not seen before on any intelligence scale: digit span, symbol search and mazes span (Gregory, 1996, p. 209). The test was revised in 1974 (WISC-R), again in 1991 (WISC-III) and in 2003, which is the current version of the WISC-IV (Niolin, 2005). As the WISC-III was being used, some researchers found that they could use Verbal and Performance IQ, and these could be supplemented by a third test that they labeled Freedom from Distractibility (Niolin, 2005). The WISC-V has 10 core subtests with 5 additional subtests and tjat are summed up into four indexes and one Full Scale IQ. This Full Scale IQ can give scores from 40 to 160. The three subtests can be modified to allow for processing abilities within the examination. Studies have been done to retest children on the WISC-IV who had already been tested on the WISC-III and they showed about a 5 point drop in the Full Scale IQ which researchers attribute to the new test items (Niolin, 2005). The WISC- IV measures several important areas: Verbal Comprehension Index (VCI) This area includes core subtests of similarities, comprehension and vocabulary. It provides a measure of verbal concept formation and assesses a childs ability to answer a question using formal and informal education. They must be able to do simple reasoning and then give their answers aloud (Indiana Purdue University, n.d.). The supplemental subtests are information and word. Perceptual Reasoning Index (PPI) This index includes the core subtests of block design, matrix reasoning and picture concepts. There is a supplementary subtest of picture completion. This index measures non-verbal and fluid reasoning. The child must have the ability to examine a specific problem, use visual-motor and/or visual spatial skills, organize their thoughts into a creative solution and then test their solution. This area can also test learning styles, particularly in the differences in visual versus other forms of learning, their comfort with new or unexpected situations and whether they are comfortable learning by doing a task versus listening or observation (Indiana Purdue University, n.d.). Working Memory Index (WMI) This index includes the core subtests of digit span and letter number sequencing, with a supplementary subtest of arithmetic. The index measures the working memory. It assesses a childs ability to memorize new information and retain it in short-term memory. It also measures the ability to concentrate and manipulate the information into reasoning. Also, an understanding of how the child plans, their flexibility in cognitive processing and their sequential skill can be measured in this index (Indiana Purdue University, n.d.). Processing Speed Index (PSI) This index includes the core subtests of coding and symbol search, and supplementary subtest of cancellation. It measures the speed in which the child processes information. I t is helpful in assessing a childs ability to quickly focus their attention and then quickly scan visual information and then to discriminate between different types of visual information and sequentially order it. This will measure high or low processing speed. The WISC-IV is administered individually and its purpose is to test the childs cognitive abilities (Maller, 2003). The test requires at least 65 minutes and can go to 80 minutes. If the supplemental tests are being used, the administrator should allow an extra 15 minutes to take the test. The manual is easy to use and there are scoring instructions that are clearly written and it has artwork that shows good examples (Maller, 2003). The following list gives a short explanation of some of the WISC-IV subtests: 1. Word reasoning -- reasoning with verbal material. It measures a childs ability to tell what words mean. 2. Matrix reasoning -- children are given a grid that is partially filled in and they must fill in the next part of the grid. 3. Picture concepts -- the child is given two or three rows of objects at a time and must pick the next objects in the sequence. Children have to understand how concepts go together in order to process these. 4. Letter number sequencing -- the children are given a series of numbers and letters that they must put in a sequence (numbers in order from lowest to highest, letters in alphabetical order). 5. Cancellation -- A series of "structured animal target forms" (Indiana Purdue University, n.d., p. 3) are given to the child and they must put a strike through the one(s) that do not belong in the sequence. Psychometric Qualities of the Test The WISC-IV was standardized on 2,200 cases of children between the ages of 6 and 16 years of age. They were "carefully selected" (Hogan, p. 308) to represent every child in the United States listed in the March 2000 U.S. Census Bureau. They were selected on the basis of "gender, geographic region, race/ethnicity and the level of parents education" (Hogan, p. 308). The WISC-IV is classified as a level C test, which means that the individual administering it must have "substantial graduate training and supervision in assessment" (Madle, 2007) and must be familiar with the Standards for Educational and Psychological Testing; these credentials are needed in order to administer, score and interpret the test Madle, 2007). Reliability It has a reliability score similar to the WISC-III, which is .92 on the full scale (Kline, 2005). Process scores and Composite scales used the split-half method with the Spearman-Brown correction scale but they did not say how the halves were divided (Maller, 2003).The internal consistencies for three of the tests, the Verbal, Performance and Full IQ scores were above 0.95. Test-retest reliabilities were high and for the four index scores they were 0.90 (Hogan, 2005). The Full Scale IQ (FSIQ) shows r =97, and the index scores have a reliability score in the low .90s, with subtest scores in the mid-range of .80s. The average coefficients across age groups ranged from .79 to .90 and for core subtests .79 to .90, and for supplemental subtests, .79 and .88 (Maller, 2003). Test re-test stability for the FSIQ has an average score of .93 and the Index Scores are generally within the high .80s range along with the subtest scores. (Hogan, 2007). Based on a sample of 243 examinees, test-retest reliability showed score stability (n=18 to 27 in each age group) (Maller, 2003). Time intervals ranged from 13 days to 2 months, though the average interval was one month. Information is still needed per age group in terms of sample sizes, demographic characteristics and retest intervals. Validity The content validity for this test was based on extensive literature reviews and input from panels, consultants, and various psychologists. During the national tryouts, the items were reviewed by "content and bias experts" (Maller, p. 2). According to Hogan, "Overall, this is a very reliable test, with the usual precaution that the shorter the test, the less reliable." (Hogan, p. 309). Validity data for the WISC-IV is listed in the manual and includes correlations with a wide variety of other tests, factor analyses that support the composite scores, and a description of the performance of the test by several other groups (Hogan, 2007). Uses of the Test There are a variety of uses for the WISC-IV and since it is considered the most widely used test, there have been several studies done on a variety of children. To understand how this test had been used, this researcher turned to academic journal articles. Most of the research that was found was done on the WISC-III, because it was more widely researched than the WISC-IV at this time. Vance, Sinter and Engin (1980) used the test with children who had learning disabilities. Their particular interest was in understanding whether there were gender differences on various scales. They found that boys scored higher (not significantly) on the six verbal subtests and females scored significantly higher on the coding subtest. On the Verbal vs. Performance IQ section, it did not show that this test was useful in diagnosing learning disabilities (Vance, Singer and Engin, 1980). Children with clinical disorders were another area where the test was used. Calhoun and Dickerson-Mayes (2005) studied children with mental disorders who had challenges with learning, attention, writing, and processing speed weaknesses. They found that some children scored lower on the Coding and Symbol Search aspects while others shows no PSI at all; the most telling aspect was that those children who had anxiety disorders, oppositional-defiant disorder, and mental retardation showed no PSI differences (Processing Speed Index). Two studies were found that deal with pervasive developmental disorders. Loyama, Kamio, KInada and Kurita (2009) did a study that was similar to the study by Vance, Singer and Engin, that studied children with high functioning pervasive developmental disorders to see if there were also differences in gender, again using the PSI as the measure. They found that girls scored higher on the PSI, the Coding and Symbol Search, but scored lower on the Block Design. Both groups (boys and girls) showed weakness on the Comprehension test in verbal domain but the girls performance was relatively even but different from the boys (Koyama, Kamio, Inada and Kurita, 2009). Although their research was on the WISC-III, this is important information for the WISC-IV as well. Koyama, Inada, Tsujii, and Kurita (2008) also studied developmental disorders, using the WISC-III as a way to predict these disorders. They were able to correctly identify 95 (out of 139) children with developmental disorders. This showed that the WISC-IV was capable of predicting developmental problems that may be within a childs scope. Another area where children and adolescents have challenges when they have difficulties within their lives. Saigh, Yasik, Oberfield, Halamandaris, and Bremmer (2006) used the WISC-IV to study the performance of children who had been traumatized whether they had PTSD or not. Their study found that children performed less proficiently when they had PTSD than those who did not. This reference shows that the cognitive functioning of children who have experienced trauma can be shown through this test. Memory, learning and ability testing has been done by Siders, Kaufman, and Reynolds (2006) in which they tested 51 middle-class white children. They found that many children showed a long-term memory ability when they used the WISC-III. Generally, most of the studies found were for the WISC-III, but, there is very little difference between version III and IV. The WISC-IV is also used as an initial testing for gifted children because it gives an idea of the childs potential beyond their initial limits and it gives good diagnostic information (Silverman and Gilman, 2005). Critique of the WISC-IV (Strengths and Weaknesses) There are many strengths of the WISC-IV that are important to mention. The test is very versatile and more versatile than many others. It is the most popular test for children because it has a reputation for being accurate and reliable. The test also is available to give individually and has been proven to show a variety of opportunities to find a childs cognitive functioning. It is a very similar test to the WISC-III, which means that the manuals can be cross-referenced. Some of the items on the WISC-IV are a little more difficult than they were on the WISC-III as in the vocabulary subtest (Hogan, 2007). There is also a WISC-IV Integrated test that was created to help with the development of the Integrated revision (Madle, 2007). The WISC-IV has an updated theoretical foundations, updated norms, and many other aspects of the WISC-IV have been updated. The WISC-IV Integrated provides a "well-defined measure of intellectual ability" (Madle, 2007) which is widely accepted in many fields. In terms of weaknesses, much of the information has to do with the psychometric aspects of the test. Some of the interpretation relies on normative scores but other aspects rely in difference scores or comparisons that are lower in reliability (Madle, 2007). The reliability and validity are data is limited and there is a minimal of empirical information in the manual that supports the validity of the interpretation and they may emerge from the many comparisons that can be made. Some of the interpretations may also be based on clinical lore rather than on empirical findings (Madle, 2007). Some children were left out of the validity studies (e.g. deaf children) but there were consultants who provided some judgments of children that were left out (Maller, 2003). Measurement methods may need to become incorporated in clinical measurements as more versions of the test are done, according to Maller (2003). Also, the factor analytic methods do not report sufficient evidence in terms of the item and test bias studies (Maller, 2003). Ethical issues would suggest that the WISC-IV should only be used with children in the age group specified and the administrator should make sure that the test has been normed for the group that will be served by the test. Also, it is very important that only a person who has been trained in this test should administer it. This means that it should only be administered by an individual who has a Masters degree and several years of training. Use of WISC-IV in My Setting As stated in other papers for this course, I eventually want to work with teens. Many of the teens who come to us have problems with depression, some have addiction problems and others have learning disabilities. Many have come to our center from a referral and because they have had challenges in school. In thinking about the WISC-IV could be used in my center, I have several ideas. The major purpose of the test is to test the cognitive development in children ages 6-16. Most of the children that come to us are between the ages of 10 and 18. I could see that we would use the test for teens with learning challenges or those who had problems with processing. We only have two people that are eligible to administer this test at this time and I would be the third person. The benefits and usefulness of this test would begin with the fact that it was especially geared for the age group at our center which would be one of the reasons we should use it. Secondly, it has been tested on most of the categories of children who have come to our center, e.g. children with trauma, children with developmental challenges and so forth. I do not perceive any challenges with the test at this time. The results would be used specifically to help students in our center and with permission from parents, we may use some of our work for research to expand the information that has been used. Future Uses One of the areas where this test is being used is with gifted children as a starting point to understand where they may fall on the I.Q. scale. There may be a future use for seeing how children with disabilities will fare once they have taken this test to see how to improve their needs. This test could also be used to understand comprehension on some of the subtests. In the future, I can see that people may extend the test to include more information on children with disabilities and they may create more opportunities for younger children who may need assistance in developmental areas. Summary The WISC-IV is a very important test when you are working with children. Because updated versions have happened periodically that took into consideration any flaws that the test had from version to version, the test is for the most part reliable and valid. Although some people have criticized some of the psychometric aspects of the test, it is this researchers opinion that one test cannot do everything for every situation. The manual is clearly written so that anyone who has an interest in testing can learn much from the manual. Although it does require a Masters degree and other training specifically in the WISC-IV, it is clear that one can start to learn from the manual. Although the test has never been tested with deaf children and it has some other disabilities that have been left out, it is clear that more research can be done with it. The challenge is that Wechsler died so it is not clear how and when there will be other versions done; this could mean that there is plenty of room for improvement in the test over time. References Calhoun, S. and Mayes, S.D. (2005). Processing speed in children with clinical disorders. Psychology in the Schools. 42 (4), 333-343. doi: 10.1002/pits.20067 Gregory, R.J. (1996). Psychological testing: History, principles and applications (2nd ed). MA: Simon and Schuster. Hogan ,T.P. (2007). Psychological testing: A practical introduction (2nd ed.). NY: John Wiley & Sons. Indiana Purdue University. (n.d.). Wechsler intelligence scale for children-iv Conceptual and Interpretive Guide. Retrieved October 11, 2010 from http://www.iupui.edu/~flip/wiscdescription.pdf Kline, T.J.B. (2005). Psychological testing: A practical approach to design and evaluation. CA: Sage Publications. Koyama, T, Inada, N., Tsujii, H., and Kurita, H. (2008). Predicating children with pervasive developmental disorders using Wechsler Intelligence Scale for Children-Third Edition. Psychiatry & Clinical Neurosciences. 62 (4), 476-478. doi: 10.1111/j.1440-1819.2008.01826.x Koyama, T., Kamio, Y., Inada, N., Kurita, H. (2009). Sex differences in WISC-III profiles of children with high-functioning pervasive developmental disorders. Journal of Autism & Developmental Disorders. 39 (1), 135-141. doi: 10.1007/s10803-008-0610-6 Madle, R.A. (2007). Wechsler Intelligence Scale for Children-Fourth Edition Integrated. Mental Measurements Yearbook database. Yearbook 17 (AN: 17013214). Maller, S. (2003). Wechsler Intelligence Scale for Children Fourth Edition (Review). Mental Measurements Yearbook database, Yearbook 16. (AN: 16073105). Niolin, R. (2005). WISC IV history. Retrieved June 1, 2010 from http://www.psychpage.com/learning/library/intell/wisciv_hx.html Saigh, P.A., Yasik, A.E., Oberfield, R.A., Halamandaris, P.V., Bremner, J.D. (2006). The intellectual performance of traumatized children and adolescents with or without posttraumatic stress disorder. Journal of Abnormal Psychology. 115 (2), 332-340. doi: 10.1037/0021-843X.115.2.332 Siders, A., Kaufman, A., Reynolds, C. (2006). Do practice effects on Wechslers performance subtests relate to childrens general ability, memory, learning ability, or attention? Applied Neuropsychology. 13 (4), 242-250. doi: 10.1207/s15324826an1304_5 Silverman, L.K. and Gilman, B. (2005). Who Are the Gifted Using the New WISC-IV? Retrieved October 11, 2010 from http://www.gifteddevelopment.com/PDF_files/NewWISC.pdf Vance, H.B., Singer, M.G., Engin, A. (1980). Wisc-R subtest differences for male and female LD children and youth. Journal of Clinical Psychology. 36 (4), 953-957. Retrieved June 1, 2010 from Academic Search Premier database. Read More