Transcript WAIS-III presentation

TM
1
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
Copyright © 1997 by The Psychological Corporation. All rights reserved.
2
Revisions and Changes
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
Copyright © 1997 by The Psychological Corporation. All rights reserved.
3
Revisions and Changes
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
Copyright © 1997 by The Psychological Corporation. All rights reserved.
4
Goal 1: Continuity and Familiarity
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
Copyright © 1997 by The Psychological Corporation. All rights reserved.
5
Demographic Stratification
Variables
•
•
•
•
•
Age
Sex
Race/Ethnicity
Education Level
Geographic Region
Copyright © 1997 by The Psychological Corporation. All rights reserved.
6
Stratification Variables: Age
16– 18– 20– 25– 30– 35– 45– 55– 65– 470– 75– 80– 85–
17 19 24 29 34 44 54 64 695- 74 79 84 89
54
WAIS–
III
WMS–
III
200 200 200 200 200 200 200 200 200 200 200 150 100
100 100 100 100 100 100 100 100 100 100 100 75 75
Copyright © 1997 by The Psychological Corporation. All rights reserved.
7
Structure of the Scale
WAIS–III Levels of Performance
FSIQ
VIQ
PIQ
VCI
WMI
Vocabulary
Similarities
Information
Comprehension
Digit Span
Arithmetic
Letter–Number
Sequencing
Copyright © 1997 by The Psychological Corporation. All rights reserved.
POI
Block Design
Matrix Reasoning
Picture Completion
Picture Arrangement
PSI
Digit
Symbol
—Coding
Symbol Search
8
WAIS–III Subtests for IQ Scores
Verbal
•
•
•
•
•
•
Vocabulary
Similarities
Arithmetic
Digit Span
Information
Comprehension
Copyright © 1997 by The Psychological Corporation. All rights reserved.
Performance
•
•
•
•
•
Picture Completion
Digit Symbol—Coding
Block Design
Matrix Reasoning
Picture Arrangement
9
WAIS–III Subtests
for Index Scores
Verbal
Perceptual
Comprehension Organization
• Vocabulary
• Similarities
• Information
Working
Memory
• Picture Completion • Arithmetic
• Block Design
• Digit Span
• Matrix Reasoning • Letter–Number
Sequencing
Copyright © 1997 by The Psychological Corporation. All rights reserved.
Processing
Speed
• Digit
Symbol—Coding
• Symbol Search
10
Summary of Verbal Subtest Changes
Subtest
Vocabulary
Similarities
Arithmetic
Digit Span
Information
Comprehension
Letter–Number
Sequencing
Total
Unchanged
Items
or Slightly Substantially New
WAIS–R
Modified
Modified
Items
Total
Items
WAIS–III
35
14
14
14
29
16
25
11
13
14
18
12
0
0
1
0
1
0
8
8
6
1
6
6
33
19
20
15
18
18
—
—
—
7
7
Copyright © 1997 by The Psychological Corporation. All rights reserved.
11
Summary of Performance Subtest Changes
Subtest
Total ItemsUnchanged
WAIS–R or Slightly Substantially New
Modified
Items
Modified
Picture Completion
Digit Symbol
—Coding
Block Design
Matrix Reasoning
Picture
Arrangement
Symbol Search
Object Assembly
Total
Items
WAIS–III
20
8
2
15
25
93
9
—
93
9
—
0
0
—
40
5
26
133
14
28
10
—
4
5
—
3
0
—
1
6
60
2
11
60
5
Copyright © 1997 by The Psychological Corporation. All rights reserved.
12
Converting Raw Scores to Scaled Scores
Reference
Group
Scaled
PERF. VC PO WM PS Scores
Age-Adjusted Scaled Scores
SUBTESTS
Raw
Score VERBAL
Picture Completion
22
Vocabulary
56
Digit Symbol–Coding
54
Similarities
28
Block Design
41
Arithmetic
11
Matrix Reasoning
20
Copyright © 1997 by The Psychological Corporation. All rights reserved.
12
13
12
12
13
15
7
12
7
12
11
13
11
8
10
8
13
6
13
9
12
13
Converting Sums of Scaled Scores
to IQ and Index Scores
IQ/INDEX SCORES
VIQ
PIQ
FSIQ
Sums of Scaled Scores
62
55
117
101
106
103
53
66
58
96–
106
99–
112
99–
107
IQ/Index Scores
Percentiles
Confidence Intervals
95
%
Copyright © 1997 by The Psychological Corporation. All rights reserved.
VCI
POI WMI
PSI
14
Plotting Subtest Scores (IQ)
Copyright © 1997 by The Psychological Corporation. All rights reserved.
15
Plotting Subtest Scores (Index)
Copyright © 1997 by The Psychological Corporation. All rights reserved.
16
Determining Strengths and Weaknesses
Total
÷ No. of Subtests
Mean Score
SUBTESTS
67
7
9.57
70
7
10
=
÷
Overall Mean
137
14
9.79
Frequency of
Difference in
Statistical
Scaled Mean Difference Significance Strength Weakness Standardization
Sample
Score Score from Mean .05 Level
(+)
(–)
Vocabulary
13
9.57
3.43
2.10
Similarities
12
9.57
2.43
2.77
Arithmetic
8
9.57
–1.57
2.63
Digit Span
7
9.57
–2.57
2.40
Information
11
9.57
1.43
2.34
Comprehension 1 1
9.57
1.43
2.96
Copyright © 1997 by The Psychological Corporation. All rights reserved.
5
<5%
W
>25%
17
Discrepancy Analysis
DISCREPANCY
COMPARISONS
Verbal IQ –
Performance IQ
Score
1
Frequency of
Statistical Difference in
Score
Significance Standardization
2
Difference .05 Level
Sample
VIQ 101 PIQ 106
-5
8.48
Verbal Comprehension –
Perceptual Organization VCI 110 POI 111
-1
9.78
Verbal Comprehension –
VCI 110 WMI 80
Working Memory
30
9.08
2.3%
Perceptual Organization
– Processing Speed
32
12.13
2.6%
Digits Forward –
Backward
POI 111 PSI
FWD
Copyright © 1997 by The Psychological Corporation. All rights reserved.
7
79
BKWD
5
2
60%
18