CFA: Path Diagram I

Confirmatory Factor Analysis (CFA) explicitly specifies variable/factor relationships and it is used when you want to test a theory you have already developed, or based on your EFA. Based on the theory underlying the BFI dataset, there are five hypothesized factors: Agreeableness, Conscientiousness, Extraversion, Neuroticism, and Openness. In order to speed up estimation of the model, factor variances are set to 1 rather than estimating them freely.

Column

Fit Statistics

Both the GFI (Goodness-of-fit index = 0.84) and the CFI (Bentler CFI = 0.77) for this model are lower than 0.9, indicating not a good fit. The RMSEA (Root Mean Square Error of Approximation) is higher than 0.05, which also indicates a poor fit.


 Model Chisquare =  2192.923   Df =  265 Pr(>Chisq) = 4.360523e-300
 Goodness-of-fit index =  0.8603839
 RMSEA index =  0.0769389   90% CI: (NA, NA)
 Bentler CFI =  0.7930581
 BIC =  307.5091

 Normalized Residuals
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
-6.9425 -0.4925  0.7267  0.9490  2.5144  8.3253 

 R-square for Endogenous Variables
    A1     A2     A3     A4     A5     C1     C2     C3 
0.1320 0.3711 0.5920 0.2510 0.4962 0.3168 0.3602 0.3142 
    C4     C5     E1     E2     E3     E4     E5     N1 
0.5100 0.3932 0.3403 0.4831 0.4243 0.5073 0.3231 0.6723 
    N2     N3     N4     N5     O1     O2     O3     O4 
0.6202 0.5265 0.3608 0.2796 0.3251 0.1625 0.5495 0.0611 
    O5 
0.2073 

 Parameter Estimates
            Estimate   Std Error  z value    Pr(>|z|)     
lam[A1:AGE] -0.5111064 0.04305214 -11.871801  1.658585e-32
lam[A2:AGE]  0.7191435 0.03379027  21.282562 1.646935e-100
lam[A3:AGE]  1.0097322 0.03554920  28.403800 1.814996e-177
lam[A4:AGE]  0.7446237 0.04400746  16.920397  3.182804e-64
lam[A5:AGE]  0.9210056 0.03620403  25.439311 9.269854e-143
lam[C1:CON] -0.6656171 0.03536991 -18.818737  5.303399e-79
lam[C2:CON] -0.7814172 0.03853148 -20.279969  1.932542e-91
lam[C3:CON] -0.7147337 0.03815981 -18.730011  2.818588e-78
lam[C4:CON]  0.9992480 0.04014303  24.892189 9.039998e-137
lam[C5:CON]  1.0114786 0.04736769  21.353766 3.597454e-101
lam[E1:EXT]  0.9551618 0.04679111  20.413317  1.273427e-92
lam[E2:EXT]  1.1336295 0.04466961  25.378095 4.401783e-142
lam[E3:EXT] -0.8999288 0.03849849 -23.375690 7.553797e-121
lam[E4:EXT] -1.0500514 0.04009159 -26.191315 3.337348e-151
lam[E5:EXT] -0.7830930 0.03956836 -19.790888  3.567016e-87
lam[N1:NEU]  1.2941195 0.03987379  32.455389 4.546826e-231
lam[N2:NEU]  1.1888799 0.03871342  30.709763 4.216098e-207
lam[N3:NEU]  1.1571604 0.04205639  27.514497 1.177667e-166
lam[N4:NEU]  0.9447428 0.04371865  21.609603 1.458980e-103
lam[N5:NEU]  0.8676891 0.04677423  18.550579  8.067807e-77
lam[O1:OPE]  0.6541324 0.03712670  17.618920  1.763394e-69
lam[O2:OPE] -0.6292351 0.05120660 -12.288163  1.048624e-34
lam[O3:OPE]  0.8885251 0.03953358  22.475200 7.257528e-112
lam[O4:OPE]  0.2972076 0.04017358   7.398086  1.381609e-13
lam[O5:OPE] -0.6007384 0.04299838 -13.971188  2.336970e-44
C[AGE,CON]  -0.3568260 0.03363974 -10.607275  2.756724e-26
C[AGE,EXT]  -0.7137755 0.02291011 -31.155480 4.275217e-213
C[AGE,NEU]  -0.2239554 0.03364772  -6.655886  2.815990e-11
C[AGE,OPE]   0.3200306 0.03633095   8.808760  1.265383e-18
C[CON,EXT]   0.3588834 0.03337729  10.752322  5.778819e-27
C[CON,NEU]   0.3050043 0.03288475   9.274947  1.777069e-20
C[CON,OPE]  -0.2856980 0.03731644  -7.656091  1.916779e-14
C[EXT,NEU]   0.2774708 0.03270636   8.483697  2.181500e-17
C[EXT,OPE]  -0.4631384 0.03329989 -13.908103  5.655943e-44
C[NEU,OPE]  -0.1371004 0.03672736  -3.732922  1.892709e-04
V[A1]        1.7172345 0.07186458  23.895421 3.417572e-126
V[A2]        0.8766167 0.04125198  21.250296 3.275932e-100
V[A3]        0.7027906 0.04397615  15.981175  1.728575e-57
V[A4]        1.6543950 0.07254980  22.803579 4.225172e-115
V[A5]        0.8613558 0.04588856  18.770599  1.313965e-78
V[C1]        0.9555922 0.04478509  21.337283 5.118358e-101
V[C2]        1.0847762 0.05271263  20.579054  4.228499e-94
V[C3]        1.1150453 0.05215587  21.379096 2.091411e-101
V[C4]        0.9594147 0.05651325  16.976809  1.219375e-64
V[C5]        1.5785888 0.07923047  19.924012  2.519703e-88
V[E1]        1.7687461 0.08046367  21.981923 4.289024e-107
V[E2]        1.3751683 0.06996547  19.654957  5.243349e-86
V[E3]        1.0987259 0.05293784  20.755019  1.104387e-95
V[E4]        1.0706745 0.05598076  19.125760  1.541118e-81
V[E5]        1.2845090 0.05787751  22.193578 3.961845e-109
V[N1]        0.8162634 0.05216843  15.646693  3.499382e-55
V[N2]        0.8654649 0.04959711  17.449904  3.448088e-68
V[N3]        1.2041432 0.06056038  19.883349  5.671895e-88
V[N4]        1.5810142 0.07072700  22.353759 1.109947e-110
V[N5]        1.9400426 0.08388888  23.126337 2.516016e-118
V[O1]        0.8883171 0.04591608  19.346538  2.180039e-83
V[O2]        2.0400989 0.08967543  22.749809 1.441263e-114
V[O3]        0.6471597 0.05422094  11.935604  7.719647e-33
V[O4]        1.3566540 0.05623746  24.123671 1.411210e-128
V[O5]        1.3798807 0.06272779  21.997916 3.015200e-107
                        
lam[A1:AGE] A1 <--- AGE 
lam[A2:AGE] A2 <--- AGE 
lam[A3:AGE] A3 <--- AGE 
lam[A4:AGE] A4 <--- AGE 
lam[A5:AGE] A5 <--- AGE 
lam[C1:CON] C1 <--- CON 
lam[C2:CON] C2 <--- CON 
lam[C3:CON] C3 <--- CON 
lam[C4:CON] C4 <--- CON 
lam[C5:CON] C5 <--- CON 
lam[E1:EXT] E1 <--- EXT 
lam[E2:EXT] E2 <--- EXT 
lam[E3:EXT] E3 <--- EXT 
lam[E4:EXT] E4 <--- EXT 
lam[E5:EXT] E5 <--- EXT 
lam[N1:NEU] N1 <--- NEU 
lam[N2:NEU] N2 <--- NEU 
lam[N3:NEU] N3 <--- NEU 
lam[N4:NEU] N4 <--- NEU 
lam[N5:NEU] N5 <--- NEU 
lam[O1:OPE] O1 <--- OPE 
lam[O2:OPE] O2 <--- OPE 
lam[O3:OPE] O3 <--- OPE 
lam[O4:OPE] O4 <--- OPE 
lam[O5:OPE] O5 <--- OPE 
C[AGE,CON]  CON <--> AGE
C[AGE,EXT]  EXT <--> AGE
C[AGE,NEU]  NEU <--> AGE
C[AGE,OPE]  OPE <--> AGE
C[CON,EXT]  EXT <--> CON
C[CON,NEU]  NEU <--> CON
C[CON,OPE]  OPE <--> CON
C[EXT,NEU]  NEU <--> EXT
C[EXT,OPE]  OPE <--> EXT
C[NEU,OPE]  OPE <--> NEU
V[A1]       A1 <--> A1  
V[A2]       A2 <--> A2  
V[A3]       A3 <--> A3  
V[A4]       A4 <--> A4  
V[A5]       A5 <--> A5  
V[C1]       C1 <--> C1  
V[C2]       C2 <--> C2  
V[C3]       C3 <--> C3  
V[C4]       C4 <--> C4  
V[C5]       C5 <--> C5  
V[E1]       E1 <--> E1  
V[E2]       E2 <--> E2  
V[E3]       E3 <--> E3  
V[E4]       E4 <--> E4  
V[E5]       E5 <--> E5  
V[N1]       N1 <--> N1  
V[N2]       N2 <--> N2  
V[N3]       N3 <--> N3  
V[N4]       N4 <--> N4  
V[N5]       N5 <--> N5  
V[O1]       O1 <--> O1  
V[O2]       O2 <--> O2  
V[O3]       O3 <--> O3  
V[O4]       O4 <--> O4  
V[O5]       O5 <--> O5  

 Iterations =  27 

Improving Model Fit

Adding loadings is one way to improve model fit. With the help of modification indices, you can look at the results of an EFA with the number of factors dictated by theory and pick a couple promising item/factor relationships to add.


 5 largest modification indices, A matrix (regression coefficients):
   N1<-N2    N2<-N1   EXT<-N4   N4<-EXT   NEU<-N4 
213.16464 213.16407  94.37153  94.15554  90.59145 

  5 largest modification indices, P matrix (variances/covariances):
  N2<->N1  EXT<->N4  NEU<->N4  OPE<->E3  CON<->E5 
213.16422  94.37167  90.59180  88.67941  81.03768 

The sem library can identify the largest modification indices for you: the fourth Neuroticism item could load to the Extraversion factor, and the third Extraversion item could load to the Openness factor.


 Model Chisquare =  1997.299   Df =  263 Pr(>Chisq) = 8.075676e-264
 Goodness-of-fit index =  0.8708575
 RMSEA index =  0.0732501   90% CI: (NA, NA)
 Bentler CFI =  0.8138415
 BIC =  126.1151

 Normalized Residuals
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
-5.6878 -0.4377  0.6707  0.9574  2.5442  8.6861 

 R-square for Endogenous Variables
    A1     A2     A3     A4     A5     C1     C2     C3 
0.1324 0.3704 0.5922 0.2510 0.4964 0.3156 0.3595 0.3147 
    C4     C5     E1     E2     E3     E4     E5     N4 
0.5096 0.3948 0.3547 0.5125 0.4596 0.5416 0.3097 0.4167 
    N1     N2     N3     N5     O1     O2     O3     O4 
0.6850 0.6271 0.5244 0.2741 0.3292 0.1508 0.5587 0.0676 
    O5 
0.1957 

 Parameter Estimates
            Estimate    Std Error  z value    Pr(>|z|)     
lam[A1:AGE] -0.51176521 0.04307343 -11.881227  1.481756e-32
lam[A2:AGE]  0.71846382 0.03382237  21.242270 3.886500e-100
lam[A3:AGE]  1.00995362 0.03559221  28.375691 4.035301e-177
lam[A4:AGE]  0.74454190 0.04403654  16.907366  3.970639e-64
lam[A5:AGE]  0.92117830 0.03623927  25.419336 1.541756e-142
lam[C1:CON] -0.66439451 0.03538182 -18.777851  1.146270e-78
lam[C2:CON] -0.78067890 0.03853959 -20.256542  3.110562e-91
lam[C3:CON] -0.71536150 0.03815631 -18.748185  2.003106e-78
lam[C4:CON]  0.99884768 0.04014862  24.878758 1.263478e-136
lam[C5:CON]  1.01348600 0.04735354  21.402538 1.265301e-101
lam[E1:EXT]  0.97516749 0.04665925  20.899769  5.380437e-97
lam[E2:EXT]  1.16766550 0.04439219  26.303400 1.753436e-152
lam[E3:EXT] -0.67679819 0.04077475 -16.598463  7.149826e-62
lam[E4:EXT] -1.08493938 0.03980403 -27.257022 1.372038e-163
lam[E5:EXT] -0.76660400 0.03978190 -19.270169  9.562319e-83
lam[N4:EXT]  0.44280604 0.04224298  10.482358  1.041153e-25
lam[N1:NEU]  1.30626718 0.03977470  32.841658 1.498407e-236
lam[N2:NEU]  1.19543119 0.03866196  30.920085 6.416129e-210
lam[N3:NEU]  1.15478514 0.04208187  27.441396 8.800977e-166
lam[N4:NEU]  0.81338278 0.04308253  18.879642  1.677195e-79
lam[N5:NEU]  0.85913162 0.04683749  18.342818  3.767520e-75
lam[O1:OPE]  0.65825189 0.03635678  18.105341  2.892135e-73
lam[O2:OPE] -0.60616729 0.05068373 -11.959801  5.770001e-33
lam[O3:OPE]  0.89591536 0.03820995  23.447173 1.412671e-121
lam[O4:OPE]  0.31256165 0.03970362   7.872371  3.479813e-15
lam[O5:OPE] -0.58359535 0.04249002 -13.734880  6.275970e-43
lam[E3:OPE]  0.44801960 0.04276022  10.477486  1.096195e-25
C[AGE,CON]  -0.35685814 0.03363876 -10.608542  2.719611e-26
C[AGE,EXT]  -0.69014737 0.02369392 -29.127614 1.605180e-186
C[AGE,NEU]  -0.19592695 0.03405451  -5.753334  8.750058e-09
C[AGE,OPE]   0.34086421 0.03564357   9.563133  1.142448e-21
C[CON,EXT]   0.34888327 0.03352045  10.408072  2.277885e-25
C[CON,NEU]   0.29133860 0.03311540   8.797677  1.396770e-18
C[CON,OPE]  -0.27321142 0.03699549  -7.384992  1.524628e-13
C[EXT,NEU]   0.24030669 0.03349584   7.174225  7.271771e-13
C[EXT,OPE]  -0.36015728 0.03576233 -10.070857  7.432741e-24
C[NEU,OPE]  -0.09688721 0.03652966  -2.652289  7.994807e-03
V[A1]        1.71655997 0.07186029  23.887462 4.134693e-126
V[A2]        0.87759332 0.04131975  21.239076 4.159960e-100
V[A3]        0.70234327 0.04412033  15.918812  4.692009e-57
V[A4]        1.65451667 0.07259144  22.792173 5.482604e-115
V[A5]        0.86103724 0.04598163  18.725678  3.057524e-78
V[C1]        0.95721863 0.04482386  21.355112 3.495304e-101
V[C2]        1.08592937 0.05273941  20.590473  3.340887e-94
V[C3]        1.11414760 0.05213830  21.369080 2.591898e-101
V[C4]        0.96021486 0.05652767  16.986633  1.031418e-64
V[C5]        1.57452512 0.07916268  19.889740  4.993374e-88
V[E1]        1.73012781 0.07953590  21.752792 6.500170e-105
V[E2]        1.29684044 0.06858872  18.907489  9.895754e-80
V[E3]        1.03140684 0.04970627  20.750036  1.225004e-95
V[E4]        0.99618815 0.05480424  18.177210  7.821277e-74
V[E5]        1.31006099 0.05869744  22.318877 2.422983e-110
V[N4]        1.44278192 0.06500552  22.194761 3.858932e-109
V[N1]        0.78467472 0.05199976  15.089968  1.885344e-51
V[N2]        0.84984436 0.04943231  17.192083  3.043985e-66
V[N3]        1.20963433 0.06069007  19.931340  2.176554e-88
V[N5]        1.95481937 0.08433760  23.178503 7.502670e-119
V[O1]        0.88291061 0.04482042  19.698848  2.205808e-86
V[O2]        2.06859653 0.08969708  23.062027 1.114105e-117
V[O3]        0.63397248 0.05135152  12.345740  5.135995e-35
V[O4]        1.34729151 0.05591090  24.097116 2.679967e-128
V[O5]        1.40018295 0.06252299  22.394691 4.433818e-111
                        
lam[A1:AGE] A1 <--- AGE 
lam[A2:AGE] A2 <--- AGE 
lam[A3:AGE] A3 <--- AGE 
lam[A4:AGE] A4 <--- AGE 
lam[A5:AGE] A5 <--- AGE 
lam[C1:CON] C1 <--- CON 
lam[C2:CON] C2 <--- CON 
lam[C3:CON] C3 <--- CON 
lam[C4:CON] C4 <--- CON 
lam[C5:CON] C5 <--- CON 
lam[E1:EXT] E1 <--- EXT 
lam[E2:EXT] E2 <--- EXT 
lam[E3:EXT] E3 <--- EXT 
lam[E4:EXT] E4 <--- EXT 
lam[E5:EXT] E5 <--- EXT 
lam[N4:EXT] N4 <--- EXT 
lam[N1:NEU] N1 <--- NEU 
lam[N2:NEU] N2 <--- NEU 
lam[N3:NEU] N3 <--- NEU 
lam[N4:NEU] N4 <--- NEU 
lam[N5:NEU] N5 <--- NEU 
lam[O1:OPE] O1 <--- OPE 
lam[O2:OPE] O2 <--- OPE 
lam[O3:OPE] O3 <--- OPE 
lam[O4:OPE] O4 <--- OPE 
lam[O5:OPE] O5 <--- OPE 
lam[E3:OPE] E3 <--- OPE 
C[AGE,CON]  CON <--> AGE
C[AGE,EXT]  EXT <--> AGE
C[AGE,NEU]  NEU <--> AGE
C[AGE,OPE]  OPE <--> AGE
C[CON,EXT]  EXT <--> CON
C[CON,NEU]  NEU <--> CON
C[CON,OPE]  OPE <--> CON
C[EXT,NEU]  NEU <--> EXT
C[EXT,OPE]  OPE <--> EXT
C[NEU,OPE]  OPE <--> NEU
V[A1]       A1 <--> A1  
V[A2]       A2 <--> A2  
V[A3]       A3 <--> A3  
V[A4]       A4 <--> A4  
V[A5]       A5 <--> A5  
V[C1]       C1 <--> C1  
V[C2]       C2 <--> C2  
V[C3]       C3 <--> C3  
V[C4]       C4 <--> C4  
V[C5]       C5 <--> C5  
V[E1]       E1 <--> E1  
V[E2]       E2 <--> E2  
V[E3]       E3 <--> E3  
V[E4]       E4 <--> E4  
V[E5]       E5 <--> E5  
V[N4]       N4 <--> N4  
V[N1]       N1 <--> N1  
V[N2]       N2 <--> N2  
V[N3]       N3 <--> N3  
V[N5]       N5 <--> N5  
V[O1]       O1 <--> O1  
V[O2]       O2 <--> O2  
V[O3]       O3 <--> O3  
V[O4]       O4 <--> O4  
V[O5]       O5 <--> O5  

 Iterations =  27 

Path Diagram II

Selecting Best Model

You can conduct a likelihood ratio test to see whether the models fit significantly differently. A significant result indicates that one model fits significantly better and is thus preferred.

LR Test for Difference Between Models

               Model Df Model Chisq Df LR Chisq Pr(>Chisq)
theory_CFA          265      2192.9                       
theory_CFA_add      263      1997.3  2   195.62  < 2.2e-16
                  
theory_CFA        
theory_CFA_add ***
---
Signif. codes:  
0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Moreover, you can compare fit statistics for both models. The revised model’s CFI is higher, indicating a better fit.
[1] 0.7930581
[1] 0.8138415
The RMSEA is lower, hence indicating that adding these loadings results in a better model fit.
[1] 0.0769389        NA        NA 0.9000000
[1] 0.0732501        NA        NA 0.9000000

The BIC is also lower, also indicating that adding these loadings results in a better model fit.

[1] 307.5091
[1] 126.1151