WISC - IV (Wechsler Intelligence Scale IV)

Discussion in 'Special Ed 101' started by Sheila, Nov 11, 2007.

  1. Sheila

    Sheila Moderator


    difficult child's Processing Speed is problematic. I was trying to refresh myself on exactly what comprises Processing Speed in the WISC- IV and found a resource that others may find helpful also.

    The Processing Speed Index (PRI) comprises two subtest scores (Coding and Symbol Search) in difficult child's evaluation report:

    Processing Speed
    • Processing speed and working memory capacity are highly interrelated
    .....– Delay is the enemy of working memory
    • Allows previously retrieved content to decay or degrade
    • Reduced speed interferes with the encoding, processing, and retrieval of information

    Processing Speed
    • Slow processing interferes with the development of reading skills
    .....– Learning disabled children process information more slowly, especially rapidly changing information
    • Reduced naming speed (of letters, numbers, colors, objects) impairs word recognition and the development of reading automaticity

    Processing Speed
    • Slow processing interferes with math learning
    ....– Slow access to numeral names and arithmetic processes interferes with functioning of working memory
    • Precious capacity must be allocated to accessing labels and tracking procedures, siphoning off resources from math concepts
    • Delay increases risk of loss of working memory contents

    Processing Speed
    • Slow processing interferes with math learning
    .....– Slow access impairs efficiency, which is necessary to optimal performance of working memory
    • Only with rapid movement of information in and out of the limited-capacity working memory store is it possible to juggle information of any complexity at all

    Processing Speed
    • Slow processing interferes with written expression
    .....– Hinders efficient shifting of working memory focus within hierarchy of multiple demands
    • Vocabulary, spelling, mechanics, grammar rules, ideas, transitions, organization, style
    .....– Individual steps (e.g., lexical retrieval) are slowed, increasing risk of losing overall task focus

    • Processing Speed Composite Score
    Processing Speed
    .....– Dynamically related to mental capacity, reading performance & development, and reasoning by conservation of resources (e.g., efficiency)
    .....– See Fry & Hale, 1996; Kail, 2000; Kail & Hall,1994; Kail & Salthouse,

    • Assesses processing speed
    • Also involves short-term memory, learning ability, visual perception, visual-motor coordination, visual scanning ability, cognitive flexibility, attention, motivation and visual and sequential processing.

    Coding Subtest
    Graphomotor speed and accuracy (fine motor control); incidental learning
    • Record student’s position at 30", 60", 90", and 120" to allow later calculation of output (speed) changes over time
    .....– Look for student who starts strong but loses momentum, student who needs to “warm up” to task
    • Compare with RAN (Speeded Naming) tasks

    Coding: Instructional Implications
    • Does the child demonstrate relative (typical) consistency in response rate?
    .....– Provide frequent breaks in work periods if performance wanes and production not much of an issue
    .....– structure expectations, provide guidelines
    • Is graphomotor speed an issue? For several clinical groups, this is problematic.
    .....– Reduce writing demands, extra time

    Symbol Search
    • Involves processing speed.
    • The subtest also involves short-term visual memory, visual-motor coordination, cognitive flexibility, visual discrimination, and concentration.
    • It may also tap auditory comprehension, perceptual organization, and planning and learning ability.

    Symbol Search Subtest
    Mental processing speed and accuracy
    • Most important use for this subtest is score comparison with Coding
    .....– Allows partialing out of fine motor (graphomotor) speed from mental processing speed

    It also contains some vague interventions near the end of the handout.

    Scatter scores in tests can be important, so I also found the following interesting:

    Interpretation of Scatter
    • Variability among subtest scores is common
    .....– Does not necessarily indicate a learning disability or other cognitive problem
    • Assess frequency of a student’s scatter using Table B.6 before assuming it to be unusual or important
    .....For example:
    .....– Over half of all students exhibit scatter of up to 7 points among the 10 Core subtests
    .....– When all 15 subtests are administered, well over a third
    of students exhibit scatter of up to 9 points
  2. Martie

    Martie Moderator


    I think math problems have to main sources: poor teaching (and poor student motivation) and underlying processing deficits.

    Mostly schools focus on reading problems but when math becomes more abstract, the deficits in processing are harder to compensate for.

    In general, there is less stigma associated with math problems than reading. Therefore, lot of kids "slip through" with math skills well below reading skills and the school is still focused on reading.

    Thank you for posting this information.

  3. wakeupcall

    wakeupcall Well-Known Member

    Sheila, difficult child is in the process of having his three-year evaluation (yes, after I squawked about it). I got out his evaluation from 3 years ago and it was interesting to see what his processing speed scores were. He scored an 83 on the Processing Speed Index; coding=77, symbol search=92. No wonder he's having reading problems. The Woodcock-Johnson III scores weren't as low. We'll see what the testing from last week brings, but I think he's having lots of problems...thus the resistance each evening to reading for 20 min. Thanks for bringing this to light.