1 Intellectual Assessment and Ability Tests
Chapter 13 covers individually administered intelligence tests.
Chapter 15 addresses many of the controversial topics related to the use of
3 Meaning of Intelligence
There is no consensus on a definition of intelligence, and there are many
General intelligence (g) vs. multiple intelligences
Intelligence is not the same thing as scores on an intelligence test.
4 Review of Intelligence Theories
Thurstone’s primary mental abilities
Cattell’s fluid (reasoning) vs. crystallized (acquired knowledge) intelligence
Hierarchical models (Carroll)
Gardner’s multiple intelligences
Sternberg’s cognitive processes
5 Sternberg’s Definition of Intelligence
“Intelligence comprises the mental abilities necessary for adaptation to, as well
as shaping and selection of, any environmental context” (Sternberg, 1997).
6 Triarchic Theory
7 Triarchic Theory cont.
Adaptation to one’s environment is the critical measure of intelligence.
Nature of intelligence:
– Components: knowledge acquisition and performance
– Context: intelligent behaviors vary by context
– Experience: when particular behaviors are intelligent
8 Important Caveats
The meaning of measured intelligence varies from test to test.
Intelligence is descriptive (not explanatory).
Intelligence tests are used to understand (not label).
Intelligence is not a single ability.
9 Individually Administered Intelligence Tests
Kaufman Assessment Battery for Children
10 Examiner Variables
Individually administered tests involve a social interaction.
Tests can be standardized, but examiner variables can never be completely
Highlights the importance of advance preparation and training.
11 Stanford-Binet: Background
Binet-Simon Scale 1905
Stanford-Binet 1960 revision introduced the deviation IQ
Stanford-Binet IV 1986
Stanford-Binet V 2003
12 Stanford-Binet: Theoretical Foundation
Measures 5 factors in both verbal and nonverbal domains:
– Fluid Reasoning
– Quantitative Reasoning
– Working Memory
13 Stanford-Binet: Characteristics
Uses standard age scores
Norms are provided across the age range in varying intervals
– 4 month interval ages 2-6
– 10 yr interval ages 23-33
M = 100; SD = 16
14 Stanford-Binet: Administration
Age range: 2-90+
Average testing time: 45-60 minutes
Two routing tests are administered, followed by all nonverbal subtests, and then
all verbal subtests.
15 Stanford-Binet: Evaluation
Continuity across all versions permits longitudinal research.
Reliability > .90 across age groups, and content, construct, and criterion validity
Administration is fairly difficult to learn compared to the other tests.
16 Kaufman Assessment Battery for Children
The KABC-II attempts to separate fluid (mental processing) and crystallized
Anchored in modern cognitive and neuropsychological theory
Designed for children ages 3-18
Mostly nonverbal items (e.g., pictorial diagrams) to minimize cultural bias
17 KABC-II Scales
Simultaneous processing (visual processing)
Sequential processing (short-term memory)
Planning ability (fluid reasoning)
Learning ability (long-term storage & retrieval)
Knowledge (crystallized ability)
18 KABC-II Administration and Scoring
Requires 35-70 minutes
Flexible procedures to facilitate cultural fairness
M = 100; SD = 15
19 Evaluation of the KABC-II
Reliabilities > .90 for the global scores and > .80 for subtests
Content, construct, and criterion validity are impressive, but there is some
question about how well mental processing really measures fluid intelligence.
20 The Wechsler Scales
Wechsler Adult Intelligence Scale (WAIS-III)
Wechsler Intelligence Scale for Children (WISC-IV)
Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III)
21 WAIS-III: Description
Includes 14 subtests, 11 of which are used in computing a Full-Scale IQ, a
Verbal IQ, and a Performance IQ
23 WAIS-III: Verbal tests
24 WAIS-III: Performance Tests
Digit Symbol Coding
25 WAIS-III: Factors
26 WAIS-III: Administration and Scoring
Subtests given separately and alternate between verbal and performance
Scoring is based on number of correct responses.
M = 100; SD = 15
27 WAIS-III: Evaluation
– Full Scale IQ: > .95
– Verbal and Performance IQs: .90-.95
– Subtests: > .70
Strong evidence of content, construct, and criterion validity
May take longer to administer than SB5, and this has led to short versions
28 WISC-IV: Description
12 subtests divided into Verbal and Performance domains
M = 100; SD = 15
29 WISC-IV: Evaluation
Reliabilities > .90
Excellent content, construct, and criterion validity (rs with academic
achievement around .50 to .70)
Much easier to administer than the SB5 but may take longer
30 Brief Intelligence Tests
Wechsler Abbreviated Scale of Intelligence (WASI)
– Requires 15-30 minutes, for ages 6-89
Kaufman Brief Intelligence Test, 2nd ed. (KBIT-II)
– Requires 20 minutes, for ages 4-90
31 Issues in Ability Testing
Bias and fairness
Impact of culture and utility of culture-reduced testing
Heritability, stability, and modifiability of IQ
32 Bias and Fairness
Bias: tendency of a test to make systematic errors in measurement or prediction
for particular groups
– Empirical data, test scores
Fairness: value judgment about the outcomes of testing
– Actions taken or decisions made
– Philosophical or politically driven
33 Types of Bias
Bias in measurement (slope bias; differential validity)
Bias in prediction (intercept bias; systematic underprediction or overprediction)
34 Possible Sources of Apparent Bias
Real mean differences
Test content is more relevant or familiar to some groups than others
Some groups are not adequately represented in the normative samples
Method of presenting the test
35 Test Fairness
Fairness is a philosophical/political consideration concerning the outcome of
using the test.
In reality, people are NOT created equal (with regard to cognitive ability), and
tests are designed to detect differences.
36 Culture-Reduced Testing
We know that it is impossible to create “culture-free” tests.
Culture-reduced testing minimizes the use of verbal or culturally specific items
(reduces culturally loaded items).
37 Utility of Culture-Reduced Testing?
Tests with less verbal, culture-specific content should minimize cultural
However, racial differences are equally large for verbal and nonverbal
Non-cognitive factors may be more influential.
38 Raven’s Progressive Matrices
Most common culture-reduced test
Completely avoids verbal content and uses multiple-choice perceptual analogies
Factor analyses support one factor: g
Reliabilities .70-.90 and evidence of construct and criterion validity
Whites typically score higher than non-Whites
39 Heritability vs. Modifiability
– identical twins (together) .85
– identical twins (apart) .67
– fraternal twins (together) .58
– siblings (together) .45
– siblings (apart) .24
40 Limitations of Heritability
Applies to populations, not individuals
Affected by environmental changes
Does not indicate modifiability of a trait
Bottom line: environment matters
41 Consistency of IQ
On average, IQ is highly stable
Stability increases with age
Meaning of stability
42 Modifiability of IQ
Can we obtain meaningful increases in IQ for disadvantaged children?
43 Correlates of IQ
Years of education
Social status and income
Other social variables