All Questions
13 questions with no upvoted or accepted answers
2
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24
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How to construct GLMM with differing random effect variance structure by group?
I have a longitudinal dataset with a normally distributed outcome variable, a normally distributed predictor variable, and a binary grouping variable. I am trying to construct a GLMM with differing ...
- 63
2
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0
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162
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How to estimate variance for identical & fraternal twins with a mixed model
I am using the twins data from OpenMx and am curious to estimate the empirical covariance structure for BMI differences in monozygous and dizygous twins:
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- 64.8k
2
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0
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295
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Using lme4 and glmer (logit) to estimate variances of random intercepts
Our data set consists of a matrix with a few thousand respondents (rows), many items of ten surveys (columns), and all 0’s and 1’s for a certain survey answering behaviour (either responding ‘I don’t ...
- 21
2
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0
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452
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Multiple comparisons for variance structure in R lme fit
How can I compare variances for different levels of a factor in a mixed effect model?
I'm fitting a mixed effects model (in R using the ...
- 121
1
vote
1
answer
178
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Estimation of random intercept and random slope for singleton cluster in multilevel modeling
I am performing some multilevel analyses with the R package lme4.
The study design is longitudinal with the hierachical structure of observations (L1) nested into study participants (L2). I have 215 ...
1
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0
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26
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Can slope variance be greater than ICC in lmer results
My question is can variance of the random slope be larger than random intercept variance? And if so, what would it mean in terms of group level variation?
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1
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85
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Is regression towards the mean happening when we use a control group?
I have a subset of 40000 participants in my study. From those I would like to study those with higher weight longitudinally, and compare them with those with healthy weight.
I observe, that those with ...
- 270
1
vote
1
answer
112
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Run mixed effect model where one fixed effects shows no variation within the random factor levels
I want to run a mixed effect model to test the effect of temperature and SLA on Herbivory. In my case, the random factor is plot since my samples are nested within ...
- 11
1
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0
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288
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Specify variance structure TOEP(1) in lmer for mixed model
How can I do the following job in R? More specific: how can I define type=toep(1) in R?
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- 11
0
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29
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Why does the ICC differ when comparing multilevel models with using log transformations of the outcome variable in R using lme4?
I'm currently working on a multilevel modeling project in R utilizing the lme4 package. The primary aim of the research is to assess the relative importance of between-family and within-family ...
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0
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26
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Linear mixed models unequeal group variances and model fit
I have data from two groups (divisions) of participants that consider attention lapses. The question is, first, do the number of attention lapses change over the two testings, and second, do the ...
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0
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252
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How does lme4 calculate residual variance for an LMM?
How does the lmer() function calculate residual variance for an LMM? If I code a model and then try to manually calculate residuals, the variance of the manually ...
- 63
0
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0
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53
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difference between estmated and empirica variance matrix of lmer random effects
Does anyone know why when I perform a lmer analysis (here using the builtin sleepstudy dataset) the estimated variance matrix of the random effects from VarCorr are so different from the variance of ...
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