This document provides information about administering and interpreting the Wechsler Adult Intelligence Scale - Third Edition (WAIS-III). It outlines Wechsler's definition of intelligence, the goals in revising and updating the WAIS-III, the structure and composition of subtests used to calculate IQ and index scores, and how to determine strengths and weaknesses in a person's cognitive profile based on their subtest scores.

1. 11
TM

2. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Wechsler’s Definition of IQ
“Intelligence is the aggregate or global capacity of the
individual to act purposefully, to think rationally and to
deal effectively with his environment.”
– Global because it characterizes individual’s
behavior as a whole
– Aggregate because it is composed of elements or abilities
that are qualitatively differentiable
Wechsler, 1939
22

3. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Goals of the WAIS–III
Goal 1: Continuity and Familiarity
Goal 2: Updating of Norms
Goal 3: Extension of Age Range
Goal 4: Age-Corrected Norms
Goal 5: Improved Item Content
Goal 6: Improved Stimulus Materials
Revisions and Changes
33

4. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Goals of the WAIS–III
Goal 7: Improved Diagnostic and Descriptive Utility
Goal 8: De-emphasis on Performance Speed
Goal 9: Enhancement of Fluid Reasoning Assessment
Goal 10: Linkage with WMS–III and WIAT
Goal 11: Extensive Validity Studies
Goal 12: Enhancement of Scoring Rules
Revisions and Changes
44

5. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Basic Description of the WAIS–III
• Individual Administration
• Assessment of Cognitive Functioning in
Adults, Aged 16–89 Years
• Scale Composition
– 11 Subtests to Obtain IQ Scores
– 11 Subtests to Obtain Index Scores
– New Subtests: Matrix Reasoning, Symbol
Search, Letter–Number Sequencing
– Optional Subtest: Object Assembly
Goal 1: Continuity and Familiarity
55

6. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Demographic Stratification
Variables
• Age
• Sex
• Race/Ethnicity
• Education Level
• Geographic Region
66

7. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Stratification Variables: Age
16–
17
18–
19
20–
24
25–
29
30–
34
35–
44
4
5-
54
55–
64
65–
69
70–
74
75–
79
80–
84
85–
89
WAIS–
III
200 200 200 200 200 200 200 200 200 200 200 150 100
WMS–
III
100 100 100 100 100 100 100 100 100 100 100 75 75
45–
54
77

8. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Structure of the Scale
WAIS–III Levels of Performance
FSIQFSIQFSIQFSIQ
Digit SpanDigit Span
ArithmeticArithmetic
Letter–NumberLetter–Number
SequencingSequencing
VocabularyVocabulary
SimilaritiesSimilarities
InformationInformation
ComprehensionComprehension
DigitDigit SymbolSymbol
—Coding—Coding
Symbol SearchSymbol Search
Block DesignBlock Design
Matrix ReasoningMatrix Reasoning
Picture CompletionPicture Completion
Picture ArrangementPicture Arrangement
VIQVIQVIQVIQ PIQPIQPIQPIQ
VCIVCIVCIVCI WMIWMIWMIWMI POIPOIPOIPOI PSIPSIPSIPSI
88

9. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
WAIS–III Subtests for IQ Scores
• Vocabulary
• Similarities
• Arithmetic
• Digit Span
• Information
• Comprehension
• Picture Completion
• Digit Symbol—Coding
• Block Design
• Matrix Reasoning
• Picture Arrangement
Verbal Performance
99

10. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
WAIS–III Subtests
for Index Scores
• Vocabulary
• Similarities
• Information
• Arithmetic
• Digit Span
• Letter–Number
Sequencing
• Picture Completion
• Block Design
• Matrix Reasoning
• Digit
Symbol—Coding
• Symbol Search
Verbal
Comprehension
Perceptual
Organization
Working
Memory
Processing
Speed
1010

11. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Summary of Verbal Subtest Changes
VocabularyVocabulary 3535 2525 00 88 3333
SimilaritiesSimilarities 1414 1111 00 88 1919
ArithmeticArithmetic 1414 1313 11 66 2020
Digit SpanDigit Span 1414 1414 00 11 1515
InformationInformation 2929 1818 11 66 1818
ComprehensionComprehension 1616 1212 00 66 1818
Letter–NumberLetter–Number
SequencingSequencing —— —— —— 77 77
Subtest
Total
Items
WAIS–R
Unchanged
or Slightly
Modified
Substantially
Modified
New
Items
Total
Items
WAIS–III
1111

12. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Summary of Performance Subtest Changes
Picture CompletionPicture Completion 2020 88 22 1515 2525
Digit SymbolDigit Symbol
—Coding—Coding 9393 9393 00 4040 133133
Block DesignBlock Design 99 99 00 55 1414
Matrix ReasoningMatrix Reasoning —— —— —— 2626 2828
PicturePicture
ArrangementArrangement 1010 55 00 66 1111
Symbol SearchSymbol Search —— —— —— 6060 6060
Object AssemblyObject Assembly 44 33 11 22 55
Subtest
Total
Items
WAIS–R
Unchanged
or Slightly
Modified
Substantially
Modified
New
Items
Total
Items
WAIS–III
1212

13. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Converting Raw Scores to Scaled Scores
SUBTESTS Raw
Score
Picture Completion
Vocabulary
Digit Symbol–Coding
Similarities
Block Design
Arithmetic
Matrix Reasoning
22 12 12 12
56 13 13 15
54 7 7 6
28 12 12 13
41 1 1 1 1 10
1 1 8 8 9
20 13 13 12
VERBAL PERF. VC PO WM PS
Reference
Group
Scaled
Scores
Age-Adjusted Scaled Scores
1313

14. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Converting Sums of Scaled Scores
to IQ and Index Scores
IQ/INDEX SCORES VIQ PIQ FSIQ VCI POI WMI PSI
Sums of Scaled Scores
IQ/Index Scores
Percentiles
Confidence Intervals
62 55 117
101 106 103
53 66 58
96– 99– 99–
106 112 107
95
1414
%

15. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Plotting Subtest Scores (IQ)
1515

16. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Plotting Subtest Scores (Index)
1616

17. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Determining Strengths and Weaknesses
13 9.57 3.43 2.10 5 <5%
12 9.57 2.43 2.77
8 9.57 –1.57 2.63
7 9.57 –2.57 2.40 W >25%
1 1 9.57 1.43 2.34
1 1 9.57 1.43 2.96
SUBTESTS
Scaled
Score
Vocabulary
Similarities
Arithmetic
Digit Span
Information
Comprehension
Mean
Score
Difference
from Mean
Statistical
Significance .
05 Level
Strength
(+)
Weakness
(–)
Frequency of
Difference in
Standardization
Sample
Total
÷ No. of Subtests
Mean Score
67 70 = 137
7 7 ÷ 14
9.57 10 9.79Overall Mean
1717

18. Copyright © 2008 by Pearson Education, Inc. or its affiliate(s). All rights reserved.
Discrepancy Analysis
101 106 -5 8.48
110 111 -1 9.78
110 80 30 9.08 2.3%
111 79 32 12.13 2.6%
DISCREPANCY
COMPARISONS
Verbal IQ –
Performance IQ
Verbal Comprehension –
Perceptual Organization
Verbal Comprehension –
Working Memory
Perceptual Organization
– Processing Speed
Score
1
Score
2 Difference
Statistical
Significance
.05 Level
Frequency of
Difference in
Standardization
Sample
VIQ PIQ
VCI POI
VCI WMI
POI PSI
Digits Forward –
Backward 7 5 2 60%
FWD BKWD
1818