WECHSLER ADULT INTELLIGENCE SCALES

• Wechsler Scale


  Developed by David Wechsler to measure the cognitive ability of individuals
• Wechsler Scale age range

  • 16.11 to 90 years old
• The original WAIS (Form I) was published

  February 1955
• WAIS is the most widely used IQ test, for both adults and older adolescents, in the world
• Intelligence


  The global capacity of a person to act purposefully, to think rationally, and to deal effectively with his environment
• Wechsler-Bellevue


  • Gathered tasks created for nonclinical purposes for administration as a "clinical test battery"
  • Used the point scale concept instead of the age scale
  • Allowed items to be grouped according to content
  • Participants were able to receive a set number of points or credits for each item passed
  • Resulted in a test that could be made up of different content areas with both an overall score and a score for each content area
  • Allowed for an analysis of an individual's ability in a variety of content areas
  • Included a Non-Verbal Performance Scale
• Non-Verbal Performance Scale


  • Allowed the measurement of nonverbal intelligence by tasks such as copying symbols or pointing to a missing detail
  • Overcame biases caused by language, culture, and education
• Wechsler-Bellevue II 1946


  Followed Wechsler-Bellevue
• WAIS 1955


  • Composed of subtests found in various other intelligence tests of the time
  • Surpassed the Stanford–Binet tests in popularity by the 1960s
• WAIS-R 1981


  • Consisted of six verbal and five performance subtests
  • Verbal tests included Information, Comprehension, Arithmetic, Digit Span, Similarities, and Vocabulary
  • Performance subtests included Picture Arrangement, Picture Completion, Block Design, Object Assembly, and Digit Symbol
  • Obtained verbal IQ, performance IQ, and full-scale IQ
• WAIS-III 1997


  • Provided scores for Verbal IQ, Performance IQ, and Full Scale IQ
  • Included four secondary indices: Verbal Comprehension, Working Memory, Perceptual Organization, and Processing Speed
• WAIS-IV 2008

  • Comprised 10 core subtests and five supplemental subtests, with the 10 core subtests making up the Full Scale IQ
  • Verbal/performance subscales from previous versions were removed and replaced by index scores
  • Introduced the General Ability Index (GAI) to measure cognitive abilities less vulnerable to impairments of processing and working memory
  • Standardized on a sample of 2,200 people in the United States ranging in age from 16 to 90
  • Conducted an extension of the standardization with 688 Canadians in the same age range
• WASI is a very short form of estimating intellectual functioning
• DAVID WECHSLER’S PHILOSOPHY ON INTELLIGENCE: '“The global capacity to act purposefully, to think rationally, and to deal effectively with [one's] environment"'
• Wechsler’s Intelligence Scale for Children = adaption of Wechsler–Bellevue Intelligence Scale


  1949
• Wechsler’s Intelligence Scale for Children


  • Subtests organized into Verbal and Performance scales
  • Verbal IQ (VIQ), Performance IQ (PIQ), and Full Scale IQ (FSIQ)
• A revised edition published as the WISC-R by Wechsler featuring the same subtests however the age range was changed from 5-15 to 6-16

  1974
• • The third edition was published as WISC-III
  • New subtest = processing speed
  • 4 new index scores: Verbal Comprehension Index (VCI), Perceptual Organization Index (POI), Freedom from Distractibility Index (FDI), Processing Speed Index (PSI)
  • Published by the Psychological Corporation


  1991
• • The WISC-IV was produced in 2003
  • Composed of 15 subtests


  2003
• • The WISC-V was published in 2014
  • Total of 21 subtests yielding 15 composite scores


  2014
• Materials Needed for Wechsler’s Intelligence Scale for Children

  • Administration and scoring manual
  • Technical and interpretive manual
  • Record form
  • Stimulus book
  • Response booklet 1 and 2
  • Block design blocks
  • Scoring key for Coding
  • Scoring key for Symbol Search
  • Cancellation scoring template
  • #2 Pencil without eraser
  • Red pencil without eraser
• VERBAL SUBTEST


  • Measures general cultural knowledge, long-term memory, and acquired facts
  • Children are asked questions about different topics like geography, science, and historical figures
• Similarities subtest


  1. Measures logical thinking, verbal concept formation, and verbal abstract reasoning

  2. Two similar but different objects or concepts are presented, and the student is asked to tell how they are alike or different
• Arithmetic subtest


  1. Measures numerical accuracy, reasoning, and mental arithmetic ability

  2. Mental arithmetic and story problems play an important part in the student’s success
• Vocabulary


  1. Measures students’ verbal fluency, concept formation, word knowledge, and word usage

  2. Children are shown pictures or a word is said aloud, and they are asked to provide the name of the object or define the word
• Comprehension


  1. Measures common-sense social knowledge, practical judgment in social situations, level of social maturation, and development of moral conscience

  2. Children are asked to explain situations, actions, or activities they'd be expected to be familiar with
• Digit Span


  1. Measures short-term auditory memory and attention

  2. Digits are presented in random order, and the student must recite them correctly and in reverse order
• Digit Span


  • For Digit Span forward, the tester reads numbers like "2, 3, 9, 1" and the child responds with the same numbers.
• Picture Completion


  1. Measures ability to recognize familiar items and identify missing parts

  2. Student separates essential and non-essential parts from the whole by observing each item closely and concentrating on picture detail
• Coding


  1. Measures visual-motor dexterity, associative nonverbal learning, and nonverbal short-term memory

  2. Fine-motor dexterity, speed, accuracy, ability to manipulate a pencil, and perceptual organization contribute to task success
• Picture Concepts

  1. Measures categorical abstract reasoning

  2. Students look at rows of pictured objects and indicate the single picture from each row that shares a characteristic in common with the single picture(s) from other row(s)
• Block Design


  1. Measures ability to analyze and synthesize an abstract design and reproduce it from colored plastic blocks

  2. Involves spatial visualization and analysis, simultaneous processing, visual-motor coordination, dexterity, and nonverbal concept formation
• Performance Subtest


  Includes Picture Completion, Coding, Picture Concepts, and Block Design
• Cancellation


  Measures visual vigilance or neglect, selective attention, and speed in processing visual information in accordance with previous attempts along the same line
• Children scan a two-page spread of relatively small colorful pictures


  The child's task is to identify all the appearances of the target animal
• Letter-Number Sequencing


  Measures attention span, short-term auditory recall, processing speed, and sequencing abilities
• Letter-Number Sequencing task


  Involves listening to and remembering a string of digits and letters read aloud at a speed of one per second, then recalling the information by repeating the numbers in chronological order, followed by the letters in alphabetical order
• Symbol Search


  Requires the student to determine whether a target symbol appears among the symbols shown in a search group
• Matrix Reasoning


  Measures visual processing and abstract, spatial perception and may be influenced by concentration, attention, and persistence
• Matrix Reasoning task


  Children are shown colored matrices or visual patterns with something missing. The child is asked to select the missing piece from a range of options