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 krishna rao posted on Wednesday, October 31, 2001 - 4:30 pm
I ran into the following problem while trying to model a nominal variable with 3 classes. I dicotomized each of the three classes giving me 3 binary variables. Now in regression analysis one would use only two of the variables keeping the third as a reference. Would one do the same in LCA or do we include all three. This was a topic of discussion among my collegues and I was hoping for some of your wisdom on this. Many thanks....
 bmuthen posted on Thursday, November 01, 2001 - 12:32 pm
You don't want to use all 3 binary variables because then you would not have conditional independence given class, but an extra direct relationship between the 3 - just like regression.
 Silvia S Martins  posted on Thursday, August 09, 2007 - 1:17 pm
I have an LCA model with binary, categorical and nominal variables. I am trying to decide whether the best model is a 4-class or a 5-class model. How do I get the different estimated probabilities plots for the different classes when I have categorical and nominal variables? How do I know to wich category the plot is referring to for a specific variable?
Than
 Linda K. Muthen posted on Tuesday, August 14, 2007 - 3:02 pm
Mplus does not give estimated probability plots for nominal variables.
 Fiona Shand posted on Monday, October 20, 2008 - 8:54 pm
I'm running LCA with 4 classes, 11 dichotomous variables and 5 demographic covariates. In the summary of categorical data proportions, one of the variables shows 5 categories even though it's a dichotomous variable. I've checked my data and it's all 0 or 1. Can you shed any light on what might be happening? Thanks.
 Linda K. Muthen posted on Tuesday, October 21, 2008 - 6:55 am
It sounds like the data are being read incorrectly. This can happen when there are blanks in the data and free format is used. Blanks are not allowed with free format data. This can also happen if the NAMES statement does not match the columns of the data set. If you cannot figure this out, please send the input, data, output, and your license number to support@statmodel.com.
 I-Chan Huang posted on Friday, April 01, 2011 - 8:09 am
I wonder can I build a "multidimensional" latent class (latent profile) model? For example, I would like to assign a adolescent to one of three categories in terms of overall academic performance based on an instrument with three domains (math, science, and reading). Thanks!

ICHUANG
 Bengt O. Muthen posted on Friday, April 01, 2011 - 8:18 am
You can do that using several (in your case 3) latent class variables. It requires a higher level of LCA skills, however. You formulate a "confirmatory LCA" where you let a certain latent class variable influence only certain items. See LTA examples in the UG for ideas on how to do this - the time points correspond to your different domains.
 Andy Daniel posted on Monday, November 19, 2012 - 7:22 am
I'm running a (longitudinal) LCA with one nominal variable (with up to 9 categories) measured at four timepoints. The output provides "means" like:

Latent Class 1

Means
Occu_t1#1 5.658
Occu_t1#2 0.161
Occu_t1#3 0.026
Occu_t2#1 15.000
Occu_t2#2 11.101
Occu_t2#3 11.014
Occu_t2#4 10.509
Occu_t2#5 8.116
Occu_t2#6 11.655
Occu_t2#7 8.930

[...]


I do not understand how to interpret the means. I guess they are logits, but it would be nice to have a example for the interpretation.

Another possibility could be that I'm completly wrong and it isn't possible to model a LCA like this and thus also the estimates are uninterpretable at all.

Thank you very much for your help!!

Best regards

Andy
 Linda K. Muthen posted on Monday, November 19, 2012 - 1:41 pm
Yes, they are logits. You can turn them into probabilities. See the example in the user's guide on page 495-496 where all covariates are zero.
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