[R] SEM model testing with identical goodness of fits (2)

hyena flyhyena at yahoo.com
Sun Mar 15 09:25:25 CET 2009


Dear John,

    Thanks for the prompt reply! Sorry did not supply with more detailed 
information.

    The target model consists of three latent factors, general risk 
scale from Weber's domain risk scales, time perspective scale from 
Zimbardo(only future time oriented) and a travel risk attitude scale. 
Variables with "prob_" prefix are items of general risk scale, variables 
of "o1" to "o12" are items of future time perspective and "v5" to "v13" 
are items of travel risk scale.

  The purpose is to explore or find a best fit model that "correctly" 
represent the underlining relationship of three scales.  So far, the 
correlated model has the best fit indices, so I 'd like to check if 
there is a higher level factor that govern all three factors, thus the 
second model.

  The data are all 5 point Likert scale scores by respondents(N=397). 
The example listed bellow did not show "prob_" variables(their names are 
too long).

   Given the following model structure, if they are indeed 
observationally indistinguishable, is there some possible adjustments to 
test the higher level factor effects?

  Thanks,

###########################
#data example, partial
#########################
                     1                   1                     1        1
  id     o1 o2 o3 o4 o5 o6 o7 o8 o9 o10 o11 o12 o13 v5 v13 v14 v16 v17
14602  2  2  4  4  5  5  2  3  2   4   3   4   2  5   2   2   4   2
14601  2  4  5  4  5  5  2  5  3   4   5   4   5  5   3   4   4   2
14606  1  3  5  5  5  5  3  3  5   3   5   5   5  5   5   5   5   3
14610  2  1  4  5  4  5  3  4  4   2   4   2   1  5   3   5   5   5
14609  4  3  2  2  5  5  2  5  2   4   4   2   2  4   2   4   4   4

####################################
#correlated model, three scales corrlated to each other
model.correlated <- specify.model()
	weber<->tp,e.webertp,NA
	tp<->tr,e.tptr,NA
	tr<->weber,e.trweber,NA
	weber<->weber,NA,1
	tp<->tp,e.tp,NA
	tr <->tr,e.trv,NA
	weber -> prob_wild_camp,alpha2,NA
	weber -> prob_book_hotel_in_short_time,alpha3,NA
	weber -> prob_safari_Kenia, alpha4, NA
	weber -> prob_sail_wild_water,alpha5,NA
	weber -> prob_dangerous_sport,alpha7,NA
	weber -> prob_bungee_jumping,alpha8,NA
	weber -> prob_tornado_tracking,alpha9,NA
	weber -> prob_ski,alpha10,NA
	prob_wild_camp <-> prob_wild_camp, ep2,NA
	prob_book_hotel_in_short_time <-> prob_book_hotel_in_short_time,ep3,NA
	prob_safari_Kenia <-> prob_safari_Kenia, ep4, NA
	prob_sail_wild_water <-> prob_sail_wild_water,ep5,NA
	prob_dangerous_sport <-> prob_dangerous_sport,ep7,NA
	prob_bungee_jumping <-> prob_bungee_jumping,ep8,NA
	prob_tornado_tracking <-> prob_tornado_tracking,ep9,NA
	prob_ski <-> prob_ski,ep10,NA
	tp -> o1,NA,1
	tp -> o3,beta3,NA
	tp -> o4,beta4,NA
	tp -> o5,beta5,NA
	tp -> o6,beta6,NA
	tp -> o7,beta7,NA
	tp -> o9,beta9,NA
	tp -> o10,beta10,NA
	tp -> o11,beta11,NA
	tp -> o12,beta12,NA
	o1 <-> o1,eo1,NA
	o3 <-> o3,eo3,NA
	o4 <-> o4,eo4,NA
	o5 <-> o5,eo5,NA
	o6 <-> o6,eo6,NA
	o7 <-> o7,eo7,NA
	o9 <-> o9,eo9,NA
	o10 <-> o10,eo10,NA
	o11 <-> o11,eo11,NA
	o12 <-> o12,eo12,NA
	tr -> v5, NA,1
	tr -> v13, gamma2,NA
	tr -> v14, gamma3,NA
	tr -> v16,gamma4,NA
	tr -> v17,gamma5,NA
	v5 <-> v5,ev1,NA
	v13 <-> v13,ev2,NA
	v14 <-> v14,ev3,NA
	v16 <-> v16, ev4, NA
	v17 <-> v17,ev5,NA


sem.correlated <- sem(model.correlated, cov(riskninfo_s), 397)
summary(sem.correlated)
samelist = c('weber','tp','tr')
minlist=c(names(rk),names(tp))
maxlist = NULL
path.diagram(sem2,out.file = 
"e:/sem2.dot",same.rank=samelist,min.rank=minlist,max.rank = 
maxlist,edge.labels="values",rank.direction='LR')

#############################################
#high level latent scale, a high level factor exist
##############################################
model.rsk <- specify.model()
	rsk->tp,e.rsktp,NA
	rsk->tr,e.rsktr,NA
	rsk->weber,e.rskweber,NA
	rsk<->rsk, NA,1
	weber<->weber, e.weber,NA
	tp<->tp,e.tp,NA
	tr <->tr,e.trv,NA
	weber -> prob_wild_camp,NA,1
	weber -> prob_book_hotel_in_short_time,alpha3,NA
	weber -> prob_safari_Kenia, alpha4, NA
	weber -> prob_sail_wild_water,alpha5,NA
	weber -> prob_dangerous_sport,alpha7,NA
	weber -> prob_bungee_jumping,alpha8,NA
	weber -> prob_tornado_tracking,alpha9,NA
	weber -> prob_ski,alpha10,NA
	prob_wild_camp <-> prob_wild_camp, ep2,NA
	prob_book_hotel_in_short_time <-> prob_book_hotel_in_short_time,ep3,NA
	prob_safari_Kenia <-> prob_safari_Kenia, ep4, NA
	prob_sail_wild_water <-> prob_sail_wild_water,ep5,NA
	prob_dangerous_sport <-> prob_dangerous_sport,ep7,NA
	prob_bungee_jumping <-> prob_bungee_jumping,ep8,NA
	prob_tornado_tracking <-> prob_tornado_tracking,ep9,NA
	prob_ski <-> prob_ski,ep10,NA
	tp -> o1,NA,1
	tp -> o3,beta3,NA
	tp -> o4,beta4,NA
	tp -> o5,beta5,NA
	tp -> o6,beta6,NA
	tp -> o7,beta7,NA
	tp -> o9,beta9,NA
	tp -> o10,beta10,NA
	tp -> o11,beta11,NA
	tp -> o12,beta12,NA
	o1 <-> o1,eo1,NA
	o3 <-> o3,eo3,NA
	o4 <-> o4,eo4,NA
	o5 <-> o5,eo5,NA
	o6 <-> o6,eo6,NA
	o7 <-> o7,eo7,NA
	o9 <-> o9,eo9,NA
	o10 <-> o10,eo10,NA
	o11 <-> o11,eo11,NA
	o12 <-> o12,eo12,NA
	tr -> v5, NA,1
	tr -> v13, gamma2,NA
	tr -> v14, gamma3,NA
	tr -> v16,gamma4,NA
	tr -> v17,gamma5,NA
	v5 <-> v5,ev1,NA
	v13 <-> v13,ev2,NA
	v14 <-> v14,ev3,NA
	v16 <-> v16, ev4, NA
	v17 <-> v17,ev5,NA


sem.rsk <- sem(model.rsk, cov(riskninfo_s), 397)
summary(sem.rsk)


##############
#model one results
###############
  Model Chisquare =  680.79   Df =  227 Pr(>Chisq) = 0
  Chisquare (null model) =  2443.4   Df =  253
  Goodness-of-fit index =  0.86163
  Adjusted goodness-of-fit index =  0.83176
  RMSEA index =  0.07105   90% CI: (NA, NA)
  Bentler-Bonnett NFI =  0.72137
  Tucker-Lewis NNFI =  0.7691
  Bentler CFI =  0.79282
  SRMR =  0.069628
  BIC =  -677.56

  Normalized Residuals
    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
-3.4800 -0.8490 -0.0959 -0.0186  0.6540  8.8500

  Parameter Estimates
               Estimate  Std Error z value Pr(>|z|)
e.webertp     -0.058847 0.023473  -2.5070 1.2175e-02
e.tptrl     0.151913 0.031072   4.8890 1.0134e-06
e.trweber -0.255449 0.044469  -5.7444 9.2264e-09
e.tp           0.114260 0.038652   2.9562 3.1149e-03
e.trv          0.464741 0.068395   6.7950 1.0832e-11
alpha2         0.488106 0.051868   9.4105 0.0000e+00
alpha3         0.446255 0.052422   8.5127 0.0000e+00
alpha4         0.517707 0.050863  10.1784 0.0000e+00
alpha5         0.772128 0.045863  16.8356 0.0000e+00
alpha7         0.782098 0.045754  17.0934 0.0000e+00
alpha8         0.668936 0.048092  13.9095 0.0000e+00
alpha9         0.376798 0.052977   7.1124 1.1400e-12
alpha10        0.449507 0.051885   8.6635 0.0000e+00
ep2            0.761752 0.058103  13.1104 0.0000e+00
ep3            0.800857 0.060154  13.3134 0.0000e+00
ep4            0.731980 0.056002  13.0705 0.0000e+00
ep5            0.403819 0.040155  10.0565 0.0000e+00
ep7            0.388322 0.039930   9.7250 0.0000e+00
ep8            0.552524 0.046619  11.8519 0.0000e+00
ep9            0.858023 0.063098  13.5982 0.0000e+00
ep10           0.797945 0.059651  13.3770 0.0000e+00
beta3          1.670861 0.312656   5.3441 9.0871e-08
beta4          1.536421 0.292725   5.2487 1.5319e-07
beta5          1.530081 0.294266   5.1997 1.9966e-07
beta6          1.767803 0.329486   5.3653 8.0801e-08
beta7          0.870601 0.200366   4.3451 1.3924e-05
beta9          1.692284 0.312799   5.4101 6.2975e-08
beta10         1.009742 0.224155   4.5047 6.6480e-06
beta11         1.723416 0.324593   5.3095 1.0995e-07
beta12         1.452796 0.286857   5.0645 4.0940e-07
eo1            0.885742 0.065529  13.5168 0.0000e+00
eo3            0.681004 0.055626  12.2425 0.0000e+00
eo4            0.730277 0.057682  12.6603 0.0000e+00
eo5            0.732500 0.059305  12.3514 0.0000e+00
eo6            0.642921 0.055797  11.5226 0.0000e+00
eo7            0.913393 0.066903  13.6526 0.0000e+00
eo9            0.672777 0.054994  12.2336 0.0000e+00
eo10           0.883505 0.065198  13.5512 0.0000e+00
eo11           0.660627 0.055399  11.9249 0.0000e+00
eo12           0.758847 0.059582  12.7361 0.0000e+00
gamma2         0.689244 0.089575   7.6946 1.4211e-14
gamma3         0.880574 0.093002   9.4684 0.0000e+00
gamma4         1.083443 0.092856  11.6680 0.0000e+00
gamma5         0.589127 0.087252   6.7520 1.4584e-11
ev1            0.535257 0.050039  10.6968 0.0000e+00
ev2            0.779221 0.060274  12.9280 0.0000e+00
ev3            0.639632 0.054097  11.8239 0.0000e+00
ev4            0.454467 0.048438   9.3824 0.0000e+00
ev5            0.838702 0.062929  13.3277 0.0000e+00

#####################################
#model two results
##################################
Model Chisquare =  680.79   Df =  227 Pr(>Chisq) = 0
  Chisquare (null model) =  2443.4   Df =  253
  Goodness-of-fit index =  0.86163
  Adjusted goodness-of-fit index =  0.83176
  RMSEA index =  0.07105   90% CI: (NA, NA)
  Bentler-Bonnett NFI =  0.72137
  Tucker-Lewis NNFI =  0.7691
  Bentler CFI =  0.79282
  SRMR =  0.069627
  BIC =  -677.56

  Normalized Residuals
    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
-3.4800 -0.8490 -0.0959 -0.0186  0.6540  8.8500

  Parameter Estimates
            Estimate  Std Error z value  Pr(>|z|)
e.rsktp      0.187069 0.045642   4.09859 4.1567e-05
e.rsktrl  0.812070 0.131731   6.16462 7.0652e-10
e.rskweber  -0.153542 0.038132  -4.02660 5.6589e-05
e.weber     0.214671 0.046260   4.64056 3.4746e-06
e.tp        0.079263 0.028484   2.78270 5.3909e-03
e.trv      -0.194712 0.197101  -0.98788 3.2321e-01
alpha3      0.914263 0.131132   6.97206 3.1233e-12
alpha4      1.060649 0.143622   7.38499 1.5254e-13
alpha5      1.581889 0.177961   8.88898 0.0000e+00
alpha7      1.602316 0.182893   8.76095 0.0000e+00
alpha8      1.370476 0.164966   8.30764 0.0000e+00
alpha9      0.771961 0.128670   5.99955 1.9787e-09
alpha10     0.920922 0.136148   6.76413 1.3411e-11
ep2         0.761752 0.058109  13.10909 0.0000e+00
ep3         0.800856 0.060155  13.31314 0.0000e+00
ep4         0.731979 0.056003  13.07044 0.0000e+00
ep5         0.403818 0.040155  10.05643 0.0000e+00
ep7         0.388322 0.039932   9.72459 0.0000e+00
ep8         0.552523 0.046620  11.85175 0.0000e+00
ep9         0.858024 0.063099  13.59811 0.0000e+00
ep10        0.797943 0.059651  13.37694 0.0000e+00
beta3       1.670904 0.310681   5.37820 7.5234e-08
beta4       1.536444 0.290968   5.28045 1.2887e-07
beta5       1.530096 0.292603   5.22926 1.7019e-07
beta6       1.767838 0.327427   5.39918 6.6945e-08
beta7       0.870626 0.199814   4.35718 1.3175e-05
beta9       1.692309 0.310816   5.44473 5.1885e-08
beta10      1.009760 0.223270   4.52259 6.1088e-06
beta11      1.723432 0.322488   5.34417 9.0830e-08
beta12      1.452761 0.285172   5.09434 3.4997e-07
eo1         0.885741 0.065519  13.51880 0.0000e+00
eo3         0.681003 0.055625  12.24265 0.0000e+00
eo4         0.730278 0.057683  12.66029 0.0000e+00
eo5         0.732501 0.059307  12.35108 0.0000e+00
eo6         0.642919 0.055799  11.52215 0.0000e+00
eo7         0.913394 0.066900  13.65310 0.0000e+00
eo9         0.672778 0.054994  12.23360 0.0000e+00
eo10        0.883503 0.065197  13.55124 0.0000e+00
eo11        0.660630 0.055397  11.92534 0.0000e+00
eo12        0.758852 0.059582  12.73619 0.0000e+00
gamma2      0.689244 0.089545   7.69720 1.3989e-14
gamma3      0.880580 0.092955   9.47317 0.0000e+00
gamma4      1.083430 0.092789  11.67631 0.0000e+00
gamma5      0.589119 0.087233   6.75338 1.4444e-11
ev1         0.535258 0.050034  10.69783 0.0000e+00
ev2         0.779219 0.060273  12.92808 0.0000e+00
ev3         0.639627 0.054096  11.82402 0.0000e+00
ev4         0.454472 0.048437   9.38269 0.0000e+00
ev5         0.838705 0.062929  13.32769 0.0000e+00

John Fox wrote:
> Dear hyena,
> 
> Actually, looking at this a bit more closely, the first models dedicate 6
> parameters to the correlational and variational structure of the three
> variables that you mention -- 3 variances and 3 covariances; the second
> model also dedicates 6 parameters -- 3 factor loadings and 3 error variances
> (with the variance of the factor fixed as a normalization). You don't show
> the remaining structure of the models, but a good guess is that they are
> observationally indistinguishable.
> 
> John
> 
>> -----Original Message-----
>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> On
>> Behalf Of hyena
>> Sent: March-14-09 5:07 PM
>> To: r-help at stat.math.ethz.ch
>> Subject: [R] SEM model testing with identical goodness of fits
>>
>> HI,
>>
>>    I am testing several models about three latent constructs that
>> measure risk attitudes.
>> Two models with different structure obtained identical of fit measures
>> from chisqure to BIC.
>> Model1 assumes three factors are correlated with  each other and model
>> two assumes a higher order factor exist and three factors related to
>> this higher factor instead of to each other.
>>
>> Model1:
>> model.one <- specify.model()
>> 	tr<->tp,e.trtp,NA
>> 	tp<->weber,e.tpweber,NA
>> 	weber<->tr,e.webertr,NA
>> 	weber<->weber, e.weber,NA
>> 	tp<->tp,e.tp,NA
>> 	tr <->tr,e.trv,NA
>> 	....
>>
>> Model two
>> model.two <- specify.model()
>> 	rsk->tp,e.rsktp,NA
>> 	rsk->tr,e.rsktr,NA
>> 	rsk->weber,e.rskweber,NA
>> 	rsk<->rsk, NA,1
>> 	weber<->weber, e.weber,NA
>> 	tp<->tp,e.tp,NA
>> 	tr <->tr,e.trv,NA
>> 	 ....
>>
>> the summary of both sem model gives identical fit indices, using same
>> data set.
>>
>> is there some thing wrong with this mode specification?
>>
>> Thanks
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>




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