Confirmatory Factor Analysis and Measurement Models
http://openmx.psyc.virginia.edu/taxonomy/term/21/0
enBasic questions on CFA and OpenMx
http://openmx.psyc.virginia.edu/thread/2835
<p>Hi all,<br />
I am VERY new to SEM and also to OpenMx and I am trying to run a very simple CFA in OpenMx, which has 1 latent factor (F1) and 3 indicators of A, B, and C with C as my scaling variable and I have a couple of questions about the output that I got:<br />
(1) The output provides information on "Estimate", "Std. Error", "Std. Estimate", "Std. SE" and my question is: how do I derive the Std. Estimate based on the other info in the output that I got? For example, from indicator A to F1, Estimate is .6987, Std. Error is: .1245, Std. estimate is .6571, and Std. SE is .11715045. So let's say that the output didn't provide the Std. estimate. How do I obtain .6571 based on the other results?</p>
<p>(2) I compared the answers from OpenMx to the answers I got from Amos, and I got all identical results as far as standardized path loadings. However, in Amos, it gives me the standardized estimate for the path between C and F1, but in OpenMx, it only gives me standardized path coefficients for A to F1, and B to F1. Therefore, in my script, how do I get to specify that C is my scaling indicator and still allow OpenMx to estimate its standardized path loading just like in Amos? </p>
<p>Thank you so much in advance for your help on this, and please let me know if I need to clarify anything.<br />
Sincerely,<br />
Anne</p>
http://openmx.psyc.virginia.edu/thread/2835#commentsConfirmatory Factor Analysis and Measurement ModelsWed, 09 Apr 2014 19:26:08 +0000AnneN.2835 at http://openmx.psyc.virginia.eduNeed help in CFA
http://openmx.psyc.virginia.edu/thread/2825
<p>Guys,</p>
<p>I Have a basic question...though I am confused :( I wanted to know whether EFA and CFA is applied construct wise or it is applied on overall model by considering all the construct together. Please help me in this and also share if you have any reference material for this.</p>
http://openmx.psyc.virginia.edu/thread/2825#commentsConfirmatory Factor Analysis and Measurement ModelsWed, 09 Apr 2014 03:32:40 +0000Smriti2825 at http://openmx.psyc.virginia.eduNon Normal Data
http://openmx.psyc.virginia.edu/thread/2630
<p>Dear All,<br />
I need your help, using OpenMx for CFA (non normal data). Now, I am very enjoy with OpenMx than the other SEM-Software.<br />
Thank you very much</p>
http://openmx.psyc.virginia.edu/thread/2630#commentsConfirmatory Factor Analysis and Measurement ModelsFri, 28 Feb 2014 01:09:53 +0000toni.toharudin2630 at http://openmx.psyc.virginia.eduIs a total measurement model always needed in SEM??
http://openmx.psyc.virginia.edu/thread/2621
<p>Greetings!</p>
<p>Is a total measurement model always needed? I have a model with 14 latent variables, with 5-9 indicators for each variables. A total measurement model is such a huge total measurement model. Can I just simply use individual measurement models for each construct and then use path analysis (to use the mean of the indicators for the latent variables, which means, transform the latent variables to observed variables)?</p>
<p>Many thanks!</p>
<p>Best regards</p>
<p>Dan</p>
http://openmx.psyc.virginia.edu/thread/2621#commentsConfirmatory Factor Analysis and Measurement ModelsThu, 20 Feb 2014 14:51:05 +0000sunflowerdd2621 at http://openmx.psyc.virginia.eduEQS 6.2 - error: variable exceeds the number of variable read
http://openmx.psyc.virginia.edu/thread/2459
<p>Hi,<br />
I am non-expert SEM user. I am trying to run a CFA with the EQS 6.2 program. After creating the EQS input file, I tried to run EQS but in the output file I found the following sentence:<br />
*** ERROR *** VARIABLE NUMBER 1, A DEPENDENT VARIABLE, EXCEEDS THE NUMBER OF VARIABLES READ. and so on for all other variables. Could you help me to solve the problem?<br />
Thanks</p>
http://openmx.psyc.virginia.edu/thread/2459#commentsConfirmatory Factor Analysis and Measurement ModelsFri, 22 Nov 2013 15:12:15 +0000flow2459 at http://openmx.psyc.virginia.eduOpenMx runs a Two Factor Model but only returns Zero and NA Values
http://openmx.psyc.virginia.edu/thread/1899
<p>Hi,</p>
<p>I'm trying to reproduce an analysis of a congeneric two- factor- model from a textbook and I can't figure out where I am going wrong. The model has two latent factors (selfevaluation and foreignevaluation scales) with three indicators each. The output I get looks like this:</p>
<p>> summary(congeneric)<br />
free parameters:<br />
[1] lbound ubound<br />
<0 Zeilen> (oder row.names mit LĂ¤nge 0)</p>
<p>observed statistics: 0<br />
estimated parameters: 0<br />
degrees of freedom: 0<br />
-2 log likelihood: NA<br />
saturated -2 log likelihood: NA<br />
number of observations: 0<br />
chi-square: NA<br />
p: NA<br />
Information Criteria:<br />
df Penalty Parameters Penalty Sample-Size Adjusted<br />
AIC: NA NA NA<br />
BIC: NA NA NA<br />
CFI: NA<br />
TLI: NA<br />
RMSEA: NA<br />
timestamp: NULL<br />
frontend time: NULL<br />
backend time: NULL<br />
independent submodels time: NULL<br />
wall clock time: NULL<br />
cpu time: NULL<br />
openmx version number: NULL </p>
<p>I have tried all sorts of modifications to my code, but nothing helped. It seems like I must be overlooking something terribly important. I would really appreciate some help! I attached my code and the data.</p>
<p>Jens</p>
<table id="attachments" class="sticky-enabled">
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<tr class="odd"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/TwoFactorModel.r">TwoFactorModel.r</a></td><td>1.42 KB</td> </tr>
<tr class="even"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/TwoFactor_Data.dat">TwoFactor_Data.dat</a></td><td>3.66 KB</td> </tr>
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http://openmx.psyc.virginia.edu/thread/1899#commentsConfirmatory Factor Analysis and Measurement ModelsMon, 11 Feb 2013 19:30:01 +0000kouros7111899 at http://openmx.psyc.virginia.educhoice of using FIML for binary data
http://openmx.psyc.virginia.edu/thread/1722
<p>Hello,<br />
my question is quite a general newby one on whether to use FIML, and therefore OpenMX. I'd appreciate any comments on which direction to take.</p>
<p>I'm considering using it (and therefore using OpenMX) because I understood it is very well adapted to use with binary data, compared to conventional techniques (using tetrachoric correlation is often problematic, I believe, and WLS requires large numbers). However, the OpenMx Manual cites handling of missing data (which didn't worry me that much, as I was expecting to use listwise deletion):</p>
<p>'The intelligent handling of missing data is a primary reason to use FIML over other estimation techniques' (4.3.1)</p>
<p>In fact, in the data sets I will be analysing, I have between 3,000 and 30,000 cases (test candidates) and around 30 variables (test items), so my worry was mainly tetrachoric correlation, rather than WLS. My aim is to determine and verify dimensional models of two language tests and then compare them.</p>
<p>many thanks for any enlightenment,</p>
<p>Michael Corrigan</p>
http://openmx.psyc.virginia.edu/thread/1722#commentsConfirmatory Factor Analysis and Measurement ModelsFri, 09 Nov 2012 15:32:47 +0000MC1722 at http://openmx.psyc.virginia.eduiteration in one factor model not converge
http://openmx.psyc.virginia.edu/thread/1659
<p>i have four observed vaiables and fit one factor model on these four observed variable.when i am try to fit one factor model on my data which consist of ordered categorical variable with fiv ecategories. when r code run the whole programme warning message appear that "NPSOL is returned a non zero status code 1.The final iterate satisfies the optimality conditions to the accuracy requesed but the sequence of iterates has not yet converged. NPSOL was terminated because no further improvement could be made in the merit function (Mx status GREEN). "</p>
<p>what it mean please give help</p>
<p>iram</p>
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<tr class="odd"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/F3.r">F3.r</a></td><td>3.32 KB</td> </tr>
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http://openmx.psyc.virginia.edu/thread/1659#commentsConfirmatory Factor Analysis and Measurement ModelsTue, 16 Oct 2012 14:44:58 +0000iram1659 at http://openmx.psyc.virginia.edu3 Factor CFA in Mplus and OpenMX, what's missing?
http://openmx.psyc.virginia.edu/thread/1631
<p>Greetings,</p>
<p>I'm trying to transfer a 3 factor CFA from Mplus to OpenMX, and I believe I'm missing something. I've attached the syntax and output from both; however, the primary difference is the notable absence of CFI, TLI, and Chi-Squared in OpemMx. I remember seeing another post re: missing CFI/TLI, but couldn't seem to find it at second glance. I'm pretty certain this is an operator error, rather than program differences, because I have transferred a similar model in the past. Thanks for any help,</p>
<p>Sam</p>
<table id="attachments" class="sticky-enabled">
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<tr class="odd"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/open_mx.txt">open_mx.txt</a></td><td>11.29 KB</td> </tr>
<tr class="even"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/mplus_syntax.txt">mplus_syntax.txt</a></td><td>8.93 KB</td> </tr>
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http://openmx.psyc.virginia.edu/thread/1631#commentsConfirmatory Factor Analysis and Measurement ModelsFri, 28 Sep 2012 21:34:53 +0000smcquillin1631 at http://openmx.psyc.virginia.eduCFA using FIML with high missing rates in OpenMx?
http://openmx.psyc.virginia.edu/thread/1580
<p>Hello, my name is christiane and I am a new user of Open MX.<br />
In our study, we are looking for possibilites to analyse a combined data set with lots of missing data (we have combined data from 4 studies, just a few of our items were administered in each study). Can anyone tell me, if there is a covariance coverage limit implemeted in Open MX for CFA with Full-Information Maximum-likelihood (FIML)? Or how does Open MX deal with this?<br />
Thank you and best wishes,<br />
christiane</p>
http://openmx.psyc.virginia.edu/thread/1580#commentsConfirmatory Factor Analysis and Measurement ModelsTue, 04 Sep 2012 10:32:28 +0000cotto1580 at http://openmx.psyc.virginia.eduusing subscale in CFA
http://openmx.psyc.virginia.edu/thread/1397
<p>Hello </p>
<p>I want to examine the relationships between three latent variables namely: Emotional Intelligence, Self Efficacy and Geography Achievement using SEM with Amos. I used three instruments to collect data. Emotional intelligence was tested using scale consists of 39 items divided to seven subscales, self efficacy was tested using scale consists of 22 items divided to two subscales and geography achievement was tested using test consists of 40 items divided by three subscales.<br />
First, the validity of these three instruments was tested using Rasch model. Then the interval score for each subscale was calculated using WINSTEPS software. Finally, each subscale used as indicators to their latent variables (instead to use items) to conduct the CFA and SEM.<br />
My question: Is this procedure correct? I mean using subscales as indicators especially in this case when there are many latent variables and a lot of items (the model in attachment). </p>
<p>Yours truly,<br />
Al sarmi </p>
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<tr class="odd"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/Model.doc">Model.doc</a></td><td>132.5 KB</td> </tr>
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http://openmx.psyc.virginia.edu/thread/1397#commentsConfirmatory Factor Analysis and Measurement ModelsThu, 17 May 2012 16:57:41 +0000k992104901397 at http://openmx.psyc.virginia.eduFactor Scores
http://openmx.psyc.virginia.edu/thread/1294
<p>What element of model output or summary stores the factor scores from an EFA or CFA in OpenMx?</p>
http://openmx.psyc.virginia.edu/thread/1294#commentsConfirmatory Factor Analysis and Measurement ModelsThu, 08 Mar 2012 18:46:39 +0000tbates1294 at http://openmx.psyc.virginia.eduMultilevel CFA with categorical variables
http://openmx.psyc.virginia.edu/thread/1291
<p>I was hoping to find out if there was any documentation on multilevel CFA - I have a sample of children clustered within families. The model I am trying to fit has 12 observed categorical variables (0,1,2) and 4 latent variables. Could you point me in the direction of some examples?</p>
http://openmx.psyc.virginia.edu/thread/1291#commentsConfirmatory Factor Analysis and Measurement ModelsWed, 07 Mar 2012 10:06:23 +0000Kat1291 at http://openmx.psyc.virginia.eduReliability Estimation with CFA
http://openmx.psyc.virginia.edu/thread/1252
<p>Hello all,</p>
<p>I'm trying to estimate the reliability of a sub-scale using a procedure outlined in Raykov (2004), which is attached. If I understand it correctly, I need to constrain the path from each error term to its respective indicator to be equal to the sum of factor loadings. That is, the path from E1 to Y1 must equal L1+L2+...+Lk . </p>
<p>Further, I need to specify dummy latent variables with variances that are equal to my constrained residual variances.</p>
<p>I have tried to set up part of the model (syntax attached), but I can't even get the model to accept the first dummy variance (error thrown: "Error in A_free[to, from] <- nextfree : subscript out of bounds").</p>
<p>The last page of the Raykov (2004) article has LISREL syntax for the same project. Am I on the right track? Does anyone know how to set up a model like this in OpenMx?</p>
<table id="attachments" class="sticky-enabled">
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<tr class="odd"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/Raykov 2004 - Reliability with Linear Constraints.pdf">Raykov 2004 - Reliability with Linear Constraints.pdf</a></td><td>114.1 KB</td> </tr>
<tr class="even"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/Raykov Syntax.txt">Raykov Syntax.txt</a></td><td>1.02 KB</td> </tr>
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http://openmx.psyc.virginia.edu/thread/1252#commentsConfirmatory Factor Analysis and Measurement ModelsWed, 15 Feb 2012 02:10:00 +0000IanCero1252 at http://openmx.psyc.virginia.eduSpecifying Correlated Errors
http://openmx.psyc.virginia.edu/thread/1251
<p>Hello all,</p>
<p>Preemptive apologies for the rudimentary question, but I'm having trouble specifying correlated errors for a confirmatory factor model. It is possible that I am specifying them wrong, or that there is some problem with my model (I'm hoping it is the former). Currently, I am using a path specification, which indicates a double-headed arrow between my first and fifth indicator:</p>
<p>#-------------------------<br />
mxPath(from = c("ac1"),<br />
to = c("ac5"),<br />
arrows = 2,<br />
free = T,<br />
values = 1,<br />
labels = ("cov15"))<br />
#-------------------------</p>
<p>But when I run the model, I get this message: </p>
<p>"Error: The job for model 'The AC Model' exited abnormally with the error message: Backing out of parameter space region where expected covariance is non-positive-definite."</p>
<p>My Questions:</p>
<p>1. I looked in the user guide, but can't find the answer - am I specifying correlated errors correctly?</p>
<p>2. What does this error message mean? Can I salvage this model?</p>
<p>Thank you in advance for any help you can give. I'm between a rock and a hard place because the correlated errors are an important part of my thesis, so they need to be in there somehow, but I can't seem to get the model to run.</p>
<p>Ian</p>
<p>PS - syntax for the whole model is attached, if you are interested.</p>
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<tr class="odd"><td><a href="http://openmx.psyc.virginia.edu/sites/default/files/Correlated Error Syntax.txt">Correlated Error Syntax.txt</a></td><td>852 bytes</td> </tr>
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http://openmx.psyc.virginia.edu/thread/1251#commentsConfirmatory Factor Analysis and Measurement ModelsTue, 14 Feb 2012 15:22:11 +0000IanCero1251 at http://openmx.psyc.virginia.edu