Structural equation modeling

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o Kline, R. B. (2013b). Exploratory and confirmatory factor analysis. In Y. Petscher & C. Schatsschneider. (Eds.), Applied quantitative analysis in the social.
Structural equation modeling

o Rex B Kline Concordia

QICSS Set D

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CFA models

Resources o

o o

Bollen, K. A., & Hoyle, R. H. (2012). Latent variable models in structural equation modeling. In R. H. Hoyle (Ed.), Handbook of structural equation modeling (pp. 56–67). New York: Guilford. Fabrigar, L. R., & Wegener, D. T. (2012). Exploratory factor analysis. New York: Oxford University Press. Kline, R. B. (2013b). Exploratory and confirmatory factor analysis. In Y. Petscher & C. Schatsschneider (Eds.), Applied quantitative analysis in the social sciences (pp. 171–207). New York: Routledge.

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EFA o Phases: 1. 2. 3. 4.

Specification Extraction Retention Rotation D3

Extraction methods 1. Principle components analysis (PCA) 2. Principle axis factoring (PAF) 3. Alpha factoring 4. ML factoring D4

PCA X1

X2

A

X3

X4

X5

X6

B

D5

PAF E1

X1

X2

A

E2

X3

E3

E4

X4

X5

E5

E6

X6

B

D6

Indicator variance Unique

Common

Specific

Error

Systematic

1 − rXX

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EFA o Retention: No need to specify But best by theory D8

EFA o Retention: Parallel analysis Scree plots D9

4

Eigenvalue

3

2

1

0 1

2

3

4

5

6

7

8

Factor

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EFA o Rotation: 1. Orthogonal 2. Oblique D11

EFA o Orthogonal: 1. Varimax 2. Quartimax 3. Equamax D12

EFA o Oblique: 1. Promax 2. Oblimin D13

EFA o Rotation: Infinite Not identified D14

a) EFA (unrestricted; rotation)

E1

X1

E2

X2

E3

X3

E4

X4

E5

X5

A

E6

X6

B

b) CFA (restricted; no rotation)

E1 1

X1

E2 1

X2

1

E3

E4

1

X3

1

X4

E5 1

X5

E6 1

X6

1

A

B

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CFA after EFA o Does not “confirm” EFA: Restricted vs. unrestricted Items are “noisy” Follow EFA with EFA D16

CFA after EFA o

o

Osborne, J. W., & Fitzpatrick, D. C. (2012). Replication analysis in exploratory factor analysis: What it is and why it makes your analysis better. Practical Assessment, Research & Evaluation, 17. Retrieved from http://pareonline.net/pdf/ v17n15.pdf van Prooijen, J.-W., & van der Kloot, W. A. (2001). Confirmatory analysis of exploratively obtained factor structures. Educational and Psychological Measurement, 61, 777–792.

D17

D18

EG

1

1

Gender

EE

EA

1

Age

Ethnic

1

Background

D19

E1

X1

1

1

X2

1

E3

E2

1

+

X3



A

D20

CFA specification o Standard model: Continuous indicators (X) A→X←E D21

Reflective measurement

X =T+E 2 X

2 T

σ =σ +σ

rXX

2 E

2 T 2 X

σ = σ

D22

Reflective measurement

1− rXX but rXX estimates a single source

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CFA specification o Standard model: Independent E A

B D24

CFA specification o Unidimensional: Simple indicator (A → X only) No Ei

Ej D25

CFA specification o Unidimensional: Precise test Convergent validity Discriminant validity D26

CFA specification o Multidimensional: Complex indicator Ei

Ej D27

CFA specification o Ei

Ej: Indicators share something Repeated measures D28

CFA specification o Multidimensional caution: Increases complexity “Cheap” way to improve fit D29

CFA specification o Special variations: Hierarchical CFA MTMM models D30

E1 1

X1

E2 1

X2

E3

E4

1

X3

1

X4

1

E5 1

1

1

X5

X6

X7

E8 1

E9 1

X8

X9

1

1

VisualSpatial

Verbal

E7

E6

Memory 1

1

1

DVS

DVe

DMe

1

g

D31

Method 1

Method 2

1

Method 3 1

1

X1

X2

1

Trait 1

X3

X4

X5

1

X7

X6

X8

X9

1

Trait 2

Trait 3

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E1

E2

1

X1

E3

1

X2

1

E4 1

1

X3

E5

X4

1

X5

1

Trait 1

E6

E7 1

1

X6

E8

X7

E9

1

X8

1

X9

1

Trait 2

Trait 3

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CFA specification o

Eid, M., Nussbeck, F. W., Geiser, C., Cole, D. A., Gollwitzer, M., & Lischetzke, T. (2008). Structural equation modeling of multitrait-multimethod data: Different models for different types of methods. Psychological Methods, 13, 230–253.

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CFA identification o Necessary: dfM ≥ 0 Scale each latent D35

Scale E

ULI constraint:

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Scale factor 1. Reference (marker) variable ULI = 1, unstandardized 2. Standardize factors UVI = 1 3. Effects coding AVE = 1, all same metric D37

E1 1

1

X2

X1

E2

1

E3

E4

1

X3

1

1

X5

X4

E5

E6 1

X6

1

A

B

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E1 1

E2 1

X1

X2

1

A

E3

E4

1

X3

1

X4

E5 1

E6 1

X5

X6

B

1

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E1 1

X1

E2 1

X2

λ1 λ2

E3 1

X3

λ3

A

λ1 + λ 2 + λ 3 =1 3

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λ1 + λ 2 + λ 3 =1 3

λ1 = 3 − λ 2 − λ 3 λ 2 = 3 − λ1 − λ 3 λ 3 = 3 − λ1 − λ 2

D41

CFA identification o Counting parameters: 1. Exog:

Vars. + Covs.

2. Endog: Direct effects D42

CFA identification o Standard models: 1 factor, ≥ 3 indicators ≥ 2 factors, ≥ 2 indicators But… D43

CFA identification o Nonstandard models: No single heuristic Undecidable Ambiguous status D44

TABLE 6.1. Identification Rule 6.6 for Nonstandard Confirmatory Factor Analysis Models with Measurement Error Correlations

For a nonstandard CFA model with measurement error correlations to be identified, all three of the conditions listed next must hold: For each factor, at least one of the following must hold:

(Rule 6.6)

(Rule 6.6a)

1. There are at least three indicators whose errors are uncorrelated with each other. 2. There are at least two indicators whose errors are uncorrelated and either a. the errors of both indicators are not correlated with the error term of a third indicator for a different factor, or b. an equality constraint is imposed on the loadings of the two indicators. For every pair of factors, there are at least two indicators, one from each factor, whose error terms are uncorrelated.

(Rule 6.6b)

For every indicator, there is at least one other indicator (not necessarily of the same factor) with which its error term is not correlated.

(Rule 6.6c)

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(c)

1 X1

(d) EX1 1 X2

1

EX2 1 X3

X4

1 A

EX3 1

EX4 1 X1

X2

1 B

EX1 1

EX2 1 X3

EX3 1

EX4

X4

1 A

For each factor, at least one of the following must hold:

B

(Rule 6.6a)

1. There are at least three indicators whose errors are uncorrelated with each other. 2. There are at least two indicators whose errors are uncorrelated and either a. the errors of both indicators are not correlated with the error term of a third indicator for a different factor, or b. an equality constraint is imposed on the loadings of the two indicators.

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TABLE 6.2. Identification Rule 6.7 for Multiple Loadings of Complex Indicators in Nonstandard Confirmatory Factor Analysis Models and Rule 6.8 for Error Correlations of Complex Indicators

Factor loadings For every complex indicator in a nonstandard CFA model:

(Rule 6.7)

In order for the multiple factor loadings to be identified, both of the following must hold: 1. Each factor on which the complex indicator loads must satisfy Rule 6.6a for a minimum number of indicators. 2. Every pair of those factors must satisfy Rule 6.6b that each factor has an indicator that does not have an error correlation with a corresponding indicator on the other factor of that pair. Error correlations In order for error correlations that involve complex indicators to be identified, both of the following must hold: 1. Rule 6.7 is satisfied. 2. For each factor on which a complex indicator loads, there must be at least one indicator with a single loading that does not have an error correlation with the complex indicator.

(Rule 6.8)

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CFA estimates o Unstandardized: 1. Indicators loadings (B) 2. Factor, error variances 3. Factor, error covariances D48

CFA estimates o Standardized: 1. Indicators loadings (r, b) 2. Proportion unexplained 3. Factor, error correlations D49

CFA estimates o Failure to converge: 1. Data matrix (NPD) 2. Poor start values 3. Small N, 2 ind./factor D50

CFA estimates o Heywood cases (inadmissible): 1. Error variance < 0 2. | r or R2 | > 1.0 3. NPD parameter matrix D51

EMo

EFa 1

1

Father

Mother

EFM

EPr

1

FatherMother

1

Problems

EIn 1

Intimacy

1

1

Family of Origin

Marital Adjustment

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Group 2: Wives THETA-DELTA

problems

intimacy

problems -------520.305 (130.844) 3.977 - -

intimacy --------

-27.093 (104.927) -0.258 - -

father

- -

mother

- -

- -

fa_mo

- -

- -

father --------

mother --------

32.147 (29.214) 1.100 9.967 (26.870) 0.371 - -

63.416 (28.138) 2.254 - -

fa_mo --------

97.049 (25.232) 3.846

Squared Multiple Correlations for X - Variables problems -------0.520

intimacy -------1.052

father -------0.821

mother -------0.661

fa_mo -------0.531

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CFA estimates o Heywood causes: Identification Poor start values Small N, 2 inds./factor D54

CFA analysis o Testing strategy: 1. Fit 1-factor model 2. Nested under higher-order 3. Compare with χ

2 D

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EHM 1

1 Number Recall

Hand Movements

EWO

ENR

EGC

1 Word Order

1 Gestalt Closure

1

1 Spatial Memory

Triangles

EMA

ESM

EPS

1 Matrix Analogies

1 Photo Series

1

1

Sequential Processing

Simultaneous Processing

EHM 1 Hand Movements

ETr

EWO

ENR 1

Number Recall

EGC

1 Word Order

1

1 Gestalt Closure

ETr

Triangles

1 Spatial Memory

EMA

ESM

EPS

1 Matrix Analogies

1 Photo Series

1 General

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CFA analysis o Example: 4-factor model: 4 vs. 3 4 vs. 2 4 vs. 1 D57

CFA respecify o Options: 1. Number of factors 2. Indicator-factor match 3. Error correlations D58

CFA respecify o Residual patterns: Result Indicator has low standardized loading on original factor

Correlation residuals High correlation residuals with indicators of another factor

Indicator has reasonably High correlation residuals high standardized loading with indicators of another on original factor factor

Respecification Switch loading of indicator to other factor Allow indicator to also load on the other factor Allow measurement errors to covary

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CFA respecify o Wrong number of factors: Discriminant validity Convergent validity D60

CFA respecify o MIs in latent variable models: Approach with caution Nonsensical respecification May not be identified D61

EHM 1 Hand Movements

1 Number Recall

EWO

ENR 1 Word Order

EGC 1

Gestalt Closure

ETr 1

Triangles

EMA

ESM 1

Spatial Memory

EPS

1 Matrix Analogies

1 Photo Series

1

1

Sequential Processing

Simultaneous Processing

Observations = v (v + 1)/2 = 36 Parameters = 17 dfM = 19 D62

Exogenous variables

Direct effects on endogenous variables

Sequential → NR

Variances

Sequential → WO

Seq, Sim

Simultaneous → Tr

Simultaneous → SM

E terms (8)

Simultaneous → MA

Simultaneous → PS

Covariances Total

Seq

Sim

17

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Example o o o o o o

Amos EQS lavaan LISREL Mplus Stata D64

title: principles and practice of sem (4th ed.), rex kline two-factor model of the kabc-i, figure 9.7, table 13.1 data: file is "kabc-mplus.dat"; type is stdeviations correlation; nobservations = 200; variable: names are handmov numbrec wordord gesclos triangle spatmem matanalg photser; analysis: type is general; model: Sequent by handmov numbrec wordord; Simul by gesclos triangle spatmem matanalg photser ! first indicator in each list is automatically ! specified as the reference variable output: sampstat modindices(all, 0) residual standardized tech4; ! requests sample data matrix, residual diagnostics, ! modification indexes > 0, all standardized ! solutions (STDYX is reported), and estimated ! correlation matrix for all variables

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3.40 2.40 2.90 2.70 2.70 4.20 2.80 3.00 1.00 .39 1.00 .35 .67 1.00 .21 .11 .16 1.00 .32 .27 .29 .38 1.00 .40 .29 .28 .30 .47 1.00 .39 .32 .30 .31 .42 .41 1.00 .39 .29 .37 .42 .58 .51 .42 1.00

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CFA indicators o Indicators: Scale: Default ML Likert:

Other method D67

CFA indicators o Item distributions: 1. Binary (e.g., T / F) 2. Likert (3-6) 3. Likert (≥ 7) D68

CFA indicators o Estimation options: 1. Corrected ML: a. Robust SEs b. Santorra-Bentler D69

CFA indicators o Estimation options: 2. Robust WLS: a. Item thresholds b. Latent response variable D70

CFA indicators o Threshold: Location on latent dimension Differentiates categories Estimated as z D71

Example: 1 = disagree 2 = not sure 3 = agree

−1.62

1.15

D72

X3

X2

X1

EX * 1

X1*

EX *

EX *

1

1

X 2*

2

1

3

X 3*

A

D73

CFA indicators o Latent response variables: Sample polychoric Predicted polychoric Correlation residuals D74

CFA indicators o Estimation options: 3. ML + numerical integration a. ↑ computation b. Markov chain Monte Carlo D75

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CFA indicators o Estimation options: 4. IRT, ICC a. Difficulty, discrimination b. Logit, probit link D77

1.0

Probability of Correct Response

.9 .8 .7

.6

ICC

.5

difficulty

.4

tangent line

.3 .2 .1 0 −3.0

−2.0

−1.0

0

1.0

2.0

3.0

Latent Ability (θ)

D78

CFA indicators o Estimation options: 5. Bootstrapping: a. Very biased small N b. Not as developed D79

CFA indicators o Estimation options: 6. Create parcels: a. Homogenous item set b. Total score D80

It 1

It 2

●●●

It 33

1

It 34

It 35

It 66

1

Pr 2 (It 12–It 22)

1

It 68

B

Pr 3 (It 23–It 33)

Pr 4 (It 34–It 44)

Pr 5 (It 45–It 55)

1

A

It 67

●●●

It 99

1

A

Pr 1 (It 1–It 11)

●●●

C

Pr 6 (It 26–It 66)

Pr 7 (It 67–It 77)

Pr 8 (It 78–It 88)

Pr 9 (It 89–It 99)

1

B

C

D81

Cautions about parcels 1. Assumes unidimensional 2. Ways to parcel 3. Mask multidimensionality

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CFA indicators o

Edwards, M. C., Wirth, R. J., Houts, C. R., & Xi, N. (2012). Categorical data in the structural equation modeling framework. In R. Hoyle (Ed.), Handbook of structural equation modeling (pp. 195–208). New York: Guilford Press.

o

Wirth, R. J., & Edwards, M. C. (2007). Item factor analysis: Current approaches and future directions. Psychological Methods, 12, 58–79.

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CFA indicators o

Bernstein, I. H., & Teng, G. (1989). Factoring items and factoring scales are different: Spurious evidence for multidimensionality due to item categorization. Psychological Bulletin, 105, 467–477.

o

Bandalos, D. L., & Finney, S. J. (2001). Item parceling issues in structural equation modeling. In G. A. Marcoulides and R. E. Schumaker (Eds.), New developments and techniques in structural equation modeling (pp. 269–296). Mahwah, NJ: Erlbaum.

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Exploratory SEM o CFA-EFA-SR hybrid o Restricted + unrestricted o EFA part is rotated D85

E X1

1

X1

1

1 Y1

E X2 1 E X3 1

X2

EY1 Y2

1

EY2 Y3

1

E X5

1

E X6

1

1

EY4

1

Y5

Y4

EY5

1

EY6

Y6

A 1

1

X3 C

E X4

1

EY3

X4

F

1 DC

X5

1

DF

B

X6

D86

Exploratory SEM o Marsh, H. W., Morin, A. J. S., Parker, P. D., & Kaur, G. (2014). Exploratory structural equation modeling: Integration of the best features of exploratory and confirmatory factor analysis. Annual Review of Clinical Psychology, 10, 85– 110.

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