All Questions
Tagged with multi-level mixed-models
16 questions
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Linear Mixed (Multilevel) Model: Predictors and outcomes at different timepoints
I'm analysing data from a randomised controlled trial, and want to predict a change in an outcome (reduction in anxiety scores from Baseline to Week 4), based on two predictors measured at the two ...
- 1
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47
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Visualising a mixed effects model
So as the title suggests I would like to visualise these two models that I have in order to better understand their relationship. The first one is a fixed slope model and the second one is a random ...
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54
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How do I check what R used as reference level for my dichotomous outcome in a GEE analysis (using geepack)?
I've got clustered patient data of 700 patients (clustered into two groups for two different hospitals). I'm trying to figure out if a certain cardiovacsular risk factor exposure (factor with 3 levels:...
- 455
2
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98
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Random Slope model Assumptions
What are the assumptions of a random slope model? In particular I am interested in knowing the assumptions about level-1 and level-2 residuals and what are their expected theoretical distributions.
My ...
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148
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How to write code for Level 2 data for Multilevel Modeling using nlme package
I am struggling with how to describe level 2 data in my Multilevel Model in R.
I am using the nlme package.
I have longitudinal data with repeated measures. I have repeated observations for every ...
- 21
4
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669
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Estimating and plotting predicted probabilities from a multilevel ordinal logit (clmm)
I'm estimating a multilevel ordinal logit with one interaction term using clmm. The coefficients I get are interesting and statistically significant and I now want to compute and plot predicted ...
- 152
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151
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Alternative solutions to multilevel modelling due to level 2 and 3 not having enough clusters
I have been running some multilevel models on my data but have now been told my clusters are too small and I need to consider taking out two of the levels and add them in as covaraites (dummy ...
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125
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About the u and u0 values from lmer in lme4 [R]
I am learning mixed models from https://www.cmm.bris.ac.uk/lemma/login/index.php and this question is regarding an exercise in Module 5.
The data has 33,988 observations from 508 schools. The ...
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796
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Specifying a non-linear relation between random effects in R
I'm working with multilevel models to try and describe different patterns in longitudinal change. Dingemanse et al (2010) describe a 'fanning out' pattern when the random effects are perfectly ...
- 1,624
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1
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4k
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Predicting probabilities in R with mixed effects model
I have defined a binary response mixed effects model using the R function glmer as follows:
fit <-glmer(binary_r ~ cat1 + (1 | SUBJECTIDf) + (1 | cat2) + (1 | cat1:cat2),
...
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2
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1
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3k
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what is a model matrix / design matrix
I stumbeled upon the stats::model.matrix function in R. In the description it sais that it would create a design matrix. It gives me a weired number of rows, which does not correspend to neither the ...
- 1,064
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109
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Interaction not significant when using a logistic model but is significant using a poisson/negative binomial model
I ran an experiment in which participants were asked to pass a story along a 4 person 'transmission chain', a bit like the game Chinese Whispers. Person 1 reads the story and re-writes it for person 2,...
7
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2
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10k
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Standardized coefficients for lmer model
I used to use the code below to calculate standardized coefficients of a lmer model. However, with the new version of lme the structure of the returned object has changed.
How to adapt the function ...
- 8,041
2
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104
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How to model multiplicative effect of parameters/fit data at individual predictor level
I am having difficulty in fitting a model on data. Basically, I have data about the evaluation of phenotypic property (i.e. hard) of 65 palm trees by 5 judges. As an evaluation scheme, each judge ...
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392
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Adding abline to augPred plot
apologies for what is likely to be a very basic question, I am very new to R.
I am looking to read off my augPred plot in order to average out the values to provide a prediction between a time period....
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