fit indices for SEM

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jessier...@googlemail.com

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Feb 25, 2019, 4:45:25 PM2/25/19
to lavaan
Hi there
I can't get any fit indices for my SEM model. Earlier today it gave me a warning (couldn't calculate standard errors) and now it does run and I get a summary of the model but doesn't provide fit indices. Here is the code:
GCSE.model2c <- '
   VRC =~ WASIvRS_P1 + BPVSRS_P1 + YARCp11aCOMPAS_P1 + YARCp12aCOMPAS_P1 + YARCp22aCOMPAS_P1
  WR =~ CC2irregRS_P1 + TOWREsweRS_P1 + YARCswrRS_P1
  GCSE_AQA_EngLang ~ VRC + WR
  WR ~~ VRC
'

GCSE.fit2c <- sem(GCSE.model2c, data=data,
                 ordered=c("GCSE_AQA_EngLang"))

Do I need to fix something?

TIA!

Jeremy Miles

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Feb 25, 2019, 5:11:32 PM2/25/19
to lav...@googlegroups.com
The model is not going to be identified because of:

 GCSE_AQA_EngLang ~ VRC + WR
  WR ~~ VRC

These two lines are doing the same thing. I would remove the first. 



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jessier...@googlemail.com

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Feb 26, 2019, 3:56:50 AM2/26/19
to lavaan
Thank you so much for your response but if I remove the first, I won't get the regressions that I am most interested in (VRC and WR -> GCSE_AQA_EngLang)? I'll try removing the second...

jessier...@googlemail.com

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Feb 26, 2019, 4:02:00 AM2/26/19
to lavaan
I tried running:

  VRC =~ WASIvRS_P1 + BPVSRS_P1 + YARCp11aCOMPAS_P1 + YARCp12aCOMPAS_P1 + YARCp22aCOMPAS_P1
  WR =~ CC2irregRS_P1 + TOWREsweRS_P1 + YARCswrRS_P1
  GCSE_AQA_EngLang ~ VRC + WR

GCSE.fit2 <- sem(GCSE.model2, data=data)
'

And can see that it still generates the WR~~VRC variance (thanks!) and semPaths draws the model that I am after but still find that it is not identified...

jessier...@googlemail.com

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Feb 26, 2019, 4:17:41 AM2/26/19
to lavaan
All sorted now, had somehow lost fit.measures=TRUE from the summary command - learn me for doing when tired! Thanks!
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