1. Confirmatory Factor Analysis
SPSS/AMOS

2. The WISC, Verbal IQ INFOrmation – general knowledge questions
COMPrehension – of social situations and common concepts
ARITHmetic
SIMILarities – how are two words similar
VOCABulary
DIGITspan – repeating strings of digits after hearing them

3. The WISC, Performance IQ
PICTureCOMPletion – identify the missing part
PictureARrANGement – arrange pictures to tell a story.
BLOCK design – arrange blocks to match model.
OBJECT assembly – puzzles involvement arrangement into a whole
CODING – associate simple shapes with symbols coding them

4. Download From BlackBoard
CFA-WISC.sav
CFA-Wisc.amw
CFA-Wisc2.amw
CFA-Wisc-Amos-Output.doc
Bring CFA-WISC into SPSS
Analyze, AMOS

5. AMOS Open, CFA-Wisc.amw Select Data Files, Working, View Data, OK
Analysis Properties
Minimization history
Standardized estimates
Squared multiple correlations
Residual moments
Modification indices

6. Calculate Estimates
View the output path diagram
Standardized
View Text (Output)

8. Text Output Chi-square = 70.236 Degrees of freedom = 43
Probability level = .005
Poor fit or just too much power?

9. Standardized Residual Covariances
CODING
OBJECT
BLOCK
PARANG
PICTCOMP
DIGIT
.000
.159
.758
.156
.049
-.180
.358
-1.513
.331
-.301
-.414
2.062
-1.248
-1.098
.519
-.805
VOCAB
.886
-.908
-.152
-1.058
.199
-.079
SIMIL
-.931
.443
-.272
1.327
1.573
-.191
ARITH
.872
-1.884
.576
.905
-.553
.623
COMP
.413
1.186
1.159
-.073
2.112
-.431
INFO
-.333
-.872
-.965
-.127
-.464
.618
Large residuals for Comp-Pictcomp and Digit-Coding.

10. Fit
GFI = .931
CFI = .941
RMSEA = .06
Fit is not bad.

11. Modification Indices
M.I.
Par Change
CODING
<---
DIGIT
4.509
.171
OBJECT
ARITH
5.513
-.194
PICTCOMP
4.194
-.138
4.608
.143
VOCAB
PARANG
4.065
-.122
4.276
-.109
COMP
Performance IQ
4.569
.438
5.317
.142
7.109
.159
I am going to add a path from Performance to COMP.

12. CFA-Wisc2.amw has this path diagram.

13. 2 Dropped Significantly
Chi-square =
Degrees of freedom = 42
Probability level = .033
Change in 2 = ( – ) = 9.94
On 1 df, is significant.

14. Better Fit GFI = .942, had been .931 CFI = .960, had been .941
RMSEA = .050, had been .060

15. Regression Weights
The path to CODING is not significant. I am going to eliminate CODING.
Estimate
S.E.
C.R. P
COMP
<---
Verbal IQ
1.491
.254
5.860
***
INFO
2.256
.200
11.286
PICTCOMP
Performance IQ
1.790
.239
7.474
VOCAB
2.273
.201
11.297
SIMIL
2.205
.227
9.721
ARITH
1.307
.173
7.562
CODING
.253
.791
.429
OBJECT
1.633
.234
6.990
BLOCK
1.823
.219
8.310
PARANG
1.189
.224
5.302

16. CFA-Wisc3.amw has this path diagram.

17. 2 No Longer Significant
Chi-square =
Degrees of freedom = 33
Probability level = .079

18. Yet Better Fit GFI = .952, had been .942 CFI = .974, had been .960
RMSEA = .046, had been .050