The WISC–IV is designed to meet several goals:

Expand and strengthen clinical utility to support your decision making
Develop the four Index Scores as the primary interpretive structure
Improve the assessment of fluid reasoning, working memory, and processing speed
Improve subtest reliabilities, floors and ceilings from WISC–III
Link to the WIAT–II and to measures of memory (Children’s Memory Scale, CMS), adaptive behavior (Adaptive Behavior Assessment System, ABAS), emotional intelligence (Bar-On EQ), and giftedness (Gifted Rating Scale, GRS)

Changes from WISC–III
Both the look and the feel of the instrument are updated to improve the testing experience for you and the child. The WISC–IV’s modern artwork is colorful and engaging and incorporates recent changes in clothing, technology, and demographics. Instructions to both the examiner and the child are improved to make the WISC–IV even more user friendly.

Updating norms to match current U.S. census data
Replacing outdated items
Expanding the manual to include a chapter on interpretation as well as an extended discussion on validity
Reducing weight to improve kit portability
Subtest Changes
Three WISC–III subtests have been eliminated from WISC–IV: Object Assembly, Mazes and Picture Arrangement. WISC–III subtests that are now supplemental include Picture Completion, Arithmetic, and Information.

New Subtests
Several new subtests are added to reflect current clinical knowledge and practice:

Word Reasoning—measures reasoning with verbal material; child identifies underlying concept given successive clues.
Matrix Reasoning—measures fluid reasoning a (highly reliable subtest on WAIS® –III and WPPSI™–III); child is presented with a partially filled grid and asked to select the item that properly completes the matrix.
Picture Concepts—measures fluid reasoning, perceptual organization, and categorization (requires categorical reasoning without a verbal response); from each of two or three rows of objects, child selects objects that go together based on an underlying concept.
Letter-Number Sequencing—measures working memory (adapted from WAIS–III); child is presented a mixed series of numbers and letters and repeats them numbers first (in numerical order), then letters (in alphabetical order).
Cancellation—measures processing speed using random and structured animal target forms (foils are common non-animal objects).
In addition, new optional recall procedures have been added to the Coding subtest, including free recall, cued digit recall, and cued symbol recall; a coding copy procedure is also included to allow examination of graphomotor abilities apart from paired-associate learning.

Four Composite Scores
In order to make interpretation more clinical meaningful, the dual IQ and Index structure from WISC–III has been replaced with a single system of four composite scores (consistent with the Four Index Scores in WISC–III) and the Full Scale IQ. This new system helps you better understand a child’s needs in relation to contemporary theory and research in cognitive information processing.