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