An Innovative Approach to Fair Evaluations for People with Cognitive Disabilities

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• An Innovative Approach to Fair Evaluations for
  People with Cognitive Disabilities

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• Julie M. Tourigny
• and Lucy Jane Miller
• University of Colorado Health Sciences Center
• Departments of Rehabilitation Medicine
• and Pediatrics

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Abstract

• The recent revision of the Leiter (Roid and
  Miller, 1997) has rendered the scale more
  comprehensive in domains assessed, and has
  greatly improved its psychometric
  characteristics. The Leiter-R assesses the global
  intelligence of children and adolescents who
  cannot be tested using traditional methods.
  Specifically, the new assessment targets
  individuals diagnosed with all types of cognitive
  disorders including communication disorders,
  hearing impairments, motor impairments, traumatic
  brain injury, attention deficit disorder, and
  some forms of learning disability.

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Abstract (contd.)

• This assessment tool is made up of two
  subdivisions comprised of 10 subtests each the
  Visualization and Reasoning (VR) subdivision, and
  the Attention and Memory (AM) subdivision.
  Administration of the VR and AM Batteries
  provides clinicians, teachers and families with a
  comprehensive understanding of a child or
  adolescents cognitive functioning regardless of
  language or motor ability. The Leiter-R battery
  of 20 subtests plus four rating scales (parent,
  teacher, examiner and self-rating) are
  specifically designed to detect small changes in
  cognitive ability, such as those that might be
  seen after interventions, because the scaling is
  based on item response theory.

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Abstract (contd.)

• Since the scales are detailed, they can aid in
  early detection of cognitive deficits or delays,
  as well as accurate treatment and program
  planning. Another unique feature and a major
  advance over previous intelligence scales, is
  that the Leiter-R is culturally fair and focuses
  on cognitive strengths rather than cognitive
  limitations.

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Construct Validity with Childrenwith Disabilities
As an integral part of the standardization of the
Leiter-R, comparison samles of a variety of
children in the following atypical and clinical
categories (N number of subjects in the VR
Standardization sample) were identified.
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Adaptation of Administrative Procedures for
Exceptional Population

• As it relates to the Leiter-R, any person between
  the ages of 2 and 20 years, who may not obtain an
  accurate evaluation from traditional, verbally
  loaded cognitive measures, is included in the
  term Exceptional Population as used here.
• Since the Leiter-R is a nonverbal and relatively
  nonmotor ability scale, most of the instructions
  are applicable for administration of the scale to
  children with special needs.

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Adaptation of Administrative Procedures for
Exceptional Population (contd.)

• Examiners are encouraged to be creative in
  demonstrating or explaining the tasks and
  employing any method that can help the child to
  understand the task. It may be necessary to
  create unusual methods by which the child can
  communicate his/her answers to test items within
  the capabilities they have.
• Note Caution should be exercised in using
  normative scores if standardization
  administration instructions are radically changed
  in the adaptation process.

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Use and Interpretation of Growth Scores

• For children who function at a low level of
  ability and any child who is expected to be
  retested on the Leiter-R, the Growth Scores
  provide an excellent source of information. The
  Growth Scores were designed using item response
  theory so that small increments of growth could
  be measured. Growth between two testing occasions
  are more clearly seen from Growth Scores and
  growth scale item values than from the normative
  scaled scores or IQ scores. Refer to the example
  below of Julieta, a 12-year-old girl who was
  retested on the Leiter-R. Please note Growth
  Score changes that occurred from past to present
  performance on each subtest.

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Classification Accuracy of Identification of
Cognitive Delay Using Cutpoints
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Classification Accuracy of Identification of
Cognitive Delay Using Cutpoints (contd.)
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Correlation with Weschler Intelligence Scale
(WISC-III)

• A sample of 126 children, ages 6 to 16, were
  given both the Leiter-R and the WISC-III. The
  sample included 57 male, 57 Caucasian, 15
  African-American, 25 Hispanic, and 3 other
  ethnic backgrounds. Testing was conducted
  predominantly in the Midwest (35) and South
  (44), with some subjects from the Northeast
  (17) and West (3). The sample included
  normative cases (47), cognitive delay (18),
  gifted (9) and ESL-Spanish (23).

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Classification Accuracy of Leiter-R with WISCFor
Children with Cognitive Delays