OpenSEM Forums
pehkawn
Joined: 05/24/2020
Mulitlevel model with ordinal data
I've been trying to build a three-level analysis of student survey data on the relationships between teaching practices and cultural background (SES as covariate) on science achievement.
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pehkawn
Joined: 05/24/2020
Delta parameterization of ordinal veriables
There are several model parameters available for an ordinal variable that can set the
ordinal variable’s scale and location. The two most common seem to be *delta* parameterization (fixing total means and total variances to 0 and 1) and *theta* parameterization (fixing residual means and residual variances to 0 and 1).
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Hal
Joined: 09/10/2021
Standardized Parameter Estimate Confidence Intervals
I'm using the OneACE5c Sex-Limitation model script which outputs both the standardized and unstandardized parameter estimates. However, it only includes the unstandardized CIs (I believe using the "mxRun( ModelName, intervals = T" command). Is there a way to get the standardized CIs as well?
Hal
Joined: 09/10/2021
ACE Twin Model Figure
I've run an ACE model with twin data using the oneACEvc.R script from H. Maes. The full ACE model was the best fitting. I want to create a figure for this model that includes my parameter estimates. Is there a way to do so?
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JuanJMV
Joined: 07/20/2016
Sex-Limitation model in two different cohorts
Dear all,
I am trying to fit a sex-limitation model (5 groups) but in two different cohorts (1944-1980) and (1981-2000). So, I have 10 groups (MZM, MZF, DZM, DZF and DZO x 2 cohorts).
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Mike Cheung
Joined: 10/08/2009
Variance components in two-level models
Hello all,
I want to estimate the variance components in a two-level model. The estimated variances seem correct when there is only one variable. However, the estimated variances appear incorrect when more than one variable. The observation is that the between-level variances are under-estimated, whereas the within-level variances are over-estimated.
Attached is an example with 1,000 level-2 units, each with 100 level-1 units. This ensures that sampling error does not play a critical role.
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bjoyner
Joined: 01/28/2022
Bivariate Cholesky Decomposition Model - Negative Unique Environment Estimate
Hello, all!
I am attempting to examine the covariance between two variables (callous, vict3_cfa) using a bivariate cholesky decomposition model. However, when I run the models, the unique environment estimate for the best fitting model comes out as negative.
janneadolf
Joined: 02/06/2015
Bootstrapping State Space Models
I would like to bootstrap standard error estimates for the parameters of a state space model implemented using OpenMx's SSM functionality (i.e., mxExpectationStateSpace). If I hand the example model from the mxExpectationStateSpace documentation page to the mxBootstrap function it does run without any complaints. But I consistently get standard error estimates of 0 and all percentiles land on the point estimates. Is mxBootstrap not (yet) capable of handling (models implying) dependent rows of data?
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valentinav
Joined: 06/15/2020
multilevel twin analysis
Hi everyone,
Participants of my study completed a 40 trials decision-making task.
The issue is that I do not have access to many twins, so I would like to increase the power of my study considering trial level data, instead of the mean of all trials of each subject.
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valentinav
Joined: 06/15/2020
correcting raw score for age and gender
Hi Everyone,
I received suggestions to correct the the raw score for age and sex main effects, and for the age x sex interaction. However, I am not familiar with this procedure, does someone knows more about it?
So far, what I had done was to insert age a covariate in my analysis.
Thanks!
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