Modification Indices

Structurele vergelijkingsmodellen met lavaan in R

Erin Buchanan

Professor

Updating Poor Models

User model versus baseline model:
  Comparative Fit Index (CFI)                    0.879
  Tucker-Lewis Index (TLI)                       0.774

Root Mean Square Error of Approximation:
  RMSEA                                          0.128
  90 Percent Confidence Interval          0.094  0.164
  P-value RMSEA <= 0.05                          0.000

Standardized Root Mean Square Residual:
  SRMR                                           0.079
Structurele vergelijkingsmodellen met lavaan in R

Updating Poor Models (2)

Latent Variables:
          Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
  visual =~                                                             
    x1       1.000                               0.777    0.667
    x2       0.690    0.124    5.585    0.000    0.536    0.456
    x3       0.985    0.160    6.157    0.000    0.766    0.678
  speed =~                                                              
    x7       1.000                               0.622    0.572
    x8       1.204    0.170    7.090    0.000    0.749    0.741
    x9       1.052    0.147    7.142    0.000    0.654    0.649
Structurele vergelijkingsmodellen met lavaan in R

Updating Poor Models (3)

Variances:
          Estimate  Std.Err  z-value  P(>|z|)   Std.lv  Std.all
   .x1      0.754    0.110    6.838    0.000    0.754    0.555
   .x2      1.094    0.103   10.661    0.000    1.094    0.792
   .x3      0.688    0.105    6.557    0.000    0.688    0.540
   .x7      0.796    0.082    9.756    0.000    0.796    0.673
   .x8      0.461    0.077    6.002    0.000    0.461    0.451
   .x9      0.587    0.071    8.273    0.000    0.587    0.578
var(HolzingerSwineford1939$x1)
1.362898
Structurele vergelijkingsmodellen met lavaan in R

Modification Indices

modificationindices(twofactor.fit, sort = TRUE)
      lhs op rhs     mi    epc sepc.lv sepc.all sepc.nox
34     x7 ~~  x8 35.521  0.624   0.624    0.568    0.568
18 visual =~  x9 35.521  0.659   0.512    0.508    0.508
36     x8 ~~  x9 19.041 -0.527  -0.527   -0.517   -0.517
16 visual =~  x7 19.041 -0.503  -0.391   -0.359   -0.359
26     x1 ~~  x9 11.428  0.177   0.177    0.151    0.151
  • Add one at a time
  • Add parameters that make sense
Structurele vergelijkingsmodellen met lavaan in R

Updating the Model

34     x7 ~~  x8 35.521  0.624   0.624    0.568    0.568
twofactor.model <- 'visual =~ x1 + x2 + x3 
                        speed =~ x7 + x8 + x9 
                        x7 ~~ x8'
twofactor.fit <- cfa(model = twofactor.model,
                     data = HolzingerSwineford1939)
summary(twofactor.fit, standardized = TRUE, 
        fit.measures = TRUE)
User model versus baseline model:
  Comparative Fit Index (CFI)                    0.976
  Tucker-Lewis Index (TLI)                       0.949
Structurele vergelijkingsmodellen met lavaan in R

Let's practice!

Structurele vergelijkingsmodellen met lavaan in R

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