Chapter 10: Tests of Intelligence
The Binet Scales
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Directed by the French government to develop a test for identifying mentally retarded
school children for special instruction
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Considered the first intelligence test (1905)
Binet-Simon Scale Contrasted Previous Tests
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Primarily verbal with some sensorimotor tests
– Sampled on 50 normal children (3-11 years)
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1908 revision - 300 normal children (3-13 years)
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1911 revision - minor changes
1916 - Lewis M. Terman at Stanford revised the Binet
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Introduced the Stanford-Binet and Intelligence Quotient (ratio IQ)
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Ratio between mental age and chronological age MA/CA x 100
2003 - Stanford-Binet 5th Ed.
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Age 2 - Adult
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Based on a hierarchical model with general mental ability
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Cattell-Horn-Carroll (CHC) Theory of intelligence.
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Focus 5 major cognitive areas
1. Fluid reasoning
2. Knowledge
3. Quantitative Reasoning
4. Visual-Spatial Processing
5. Working Memory
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Standardization
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500 Examiners
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Stratified random sample of 4,800
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No accommodations for special needs
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Certain exclusions
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Scoring
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Raw scores summed across item scores
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0 = wrong; 1 = correct
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Converted into normative standard scores
– mean of 100, SD of 15
Psychometric Properties
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Reliabilities range
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Factor index reliability
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Range of the 10 subtests
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Concurrent and criterion validity
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Test Administration
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Adaptive Testing
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Routing Test
Teaching Items
Basal Level
Summary
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Favored test
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Focus on “g”
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High correlation to achievement tests
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Considered cumbersome to administer
David Wechsler
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Wechsler Adult Intelligence Scale - R (WAIS-R)
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Wechsler Intelligence Scale for Children - R (WISC-R)
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WAIS-IV (2008)
David Wechsler
11 subtests: 6 verbal & 5 nonverbal
Assess problem solving
IQ is relative
Summary of Wechlser Scales
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Widely used
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Strong standardization
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Long history of research
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Focus on “g”
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High correlation to achievement tests
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Low intercorrelation of several subtests
Goals of WAIS-IV
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Eliminate Dual IQ/Index Score Structure
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Enhance Measure of Fluid Intelligence
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Enhance Measure of Working Memory
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Enhance Measure of Processing Speed
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Enhance clinical utility
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Additional Special Group Studies (e.g., Mild
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Cognitive Impairment, Borderline Intellectual Functioning)
Improve Psychometric Properties
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Update Norms
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Expand FSIQ Range
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Maintain or improve reliability
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Provide initial evidence of validity
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Enhance User-Friendliness
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Reduce Testing Time
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Revise Instructions
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Redesign Record Form
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Increase Portability
Separate WAIS-IV and WMS-IV Technical Manuals (Wechsler Memory Scale)
Subtest Modifications
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4 Subtests Dropped
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12 Subtests Retained
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3 New Subtests
– Visual Puzzles, Figure Weights, Cancellation
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Visual Puzzles
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Which 3 of these pieces go together?
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Figure Weights
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Which one balances the scale?
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Cancellation
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When I say go, draw a line through each red square and yellow triangle.
Normative Sample
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Ages 16-90
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Normative sample: N = 2200
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National sample stratified by:
– Sex
– Education Level
– Ethnicity
– Region
Psychometric Properties
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The reliability coefficients for WISC–IV composite scales good
– Range?
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Interscorer agreement range
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Mean of 100; SD 15
– Subtest Scaled Scores: Mean = 10, SD = 3
Summary
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Widely used
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Strong standardization
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Long history of research
Tests for Group Administration
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Army Alpha & Beta
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Screening procedures
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Tests in schools
Pros
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Administration
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Scoring
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Cost
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Influence
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Cons
Administration
No clarification
Literacy
No innovative formats