You’ll recall the development of adult intelligence tests from earlier in the semester I hope. Thus, the WISC III offered a FSIQ as a the education of children with mental retardation preschool age of g, a Verbal and a Performance IQ for those used to the WISC R, and four new factors.
These were the Verbal Comprehension Index, Perceptual Organization Index, Freedom from Distractibility Index, and Processing Speed Index. Of note, while the Psychological Corporation believed the factor structure supported these four factors, Sattler had some doubts. The WISC IV is an update of the WISC III, and contains 10 core subtests, and 5 additional subtests, that can be summed to four indexes, and one Full Scale IQ. The FSIQ can range from 40 at the lowest to 160 at the highest.
Three subtests can be given in modified forms to allow for additional examination of processing abilities. The test takes between 65 and 80 minutes to administer to most children, with more time required if the additional subtests are given or if the client is more intelligence, and less time required for clients suffering from Mental Retardation. It can be given to children as young as 6,0 and as old as 16,11. The test overlaps with the Wechsler Preschool and Primary Scale of Intelligence — Third Edition for children between the ages of 6,0 and 7,3. While research has not been collected to determine the effect of practice on re-examination, research based on the WISC III indicated that one year was needed between administrations to avoid significant practice effects. Over the WISC IV test-retest period of 32 days, the VCI gained 2-3 points, PRI gained 3-6 points, WMI gained 1-5 points, and PSI gained 5-11 points.
As a result, the FSIQ was 6 points higher overall, ranging from 4-8 depending on the age range. While I do not recall guidelines for this in the previous version of the test, the WISC IV manual now specifies that if testing must be broken up into two sessions, they should be no more than one week apart. Use the first date of testing to compute the child’s age. Pages 9-18 discuss special considerations to take into account when testing for neuropsychological purposes and for testing children with special needs. Pages 22-24 discuss the importance of rapport in testing children.
While I have not seen research examining this in the WISC IV, in the previous version of the test, research showed that the difference between good and poor rapport could mean a difference of 10 points in final IQ scores. Working Memory us better assessed through changes made to one test and the addition of a new subtest. While this used to be called Freedom From Distractibility, the name of the index has been changed to be more consistent with the adult version of the test and current research. Processing Speed is a cleaner factor, since the two main subtests are joined and a third new subtest is added. March 2000 US Census data very closely. There were 5 levels of parental education, and 4 geographical areas covering the whole United States and Hawaii.