All Questions
128 questions
0
votes
0
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102
views
Plotting confidence and means from logistic regression in ggplot2
My data are for an experiment asking participants to detect a tone (Response= 1 or 0) in different (within-participant) conditions. I am interested in how participants' scores on separate ...
0
votes
0
answers
39
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Interpretation of logistic regression slope
I am running a logistic mixed model with a binary outcome (correct/incorrect).
I have two fixed effect predictors:
Condition (0, ‘low’ vs 1, ‘high)
Sumspq (a continuous questionnaire score)
There is ...
3
votes
1
answer
147
views
Interpreting intercept with centered predictors in logistic mixed model
I am running a logistic mixed model in lme4. The model is as follows
...
0
votes
0
answers
62
views
Why are my random effects and variance zero?
I'm trying to implement a logistic regression model with random effects and interactions. For some reason, when I remove an interaction between a parameter and a random effect parameter (Player and ...
0
votes
0
answers
50
views
Why do my random effects estimates not match the data?
I'm running a logistic regression model in R using glmer() from lme4. I only want to get the random effects estimates, so I have an intercept-only model with just ...
1
vote
1
answer
103
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mixed model specification in R (interactions and nesting)
I'm working with data from an experiment that I plan to analyze using a mixed-effects logistic model. In this study, 200 participants (identified by the variable Participant) were randomly assigned to ...
1
vote
1
answer
213
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Question about post hoc analyses for mixed-effects logistic regression model
I'm sorry for such a silly question, but I would like to ask about post hoc comparisons that I could use to follow up on a significant, although hard to interpret, three-way interaction.
I ran a mixed-...
0
votes
1
answer
199
views
model formulas for glmer
I have a glmer (library lme4) logit model that I conducted in R. I have very basic knowledge in stats and glmm models are completely new to me. My Models in R basically are like this:
...
0
votes
0
answers
104
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Using mixed effects models or clogit on paired data
I'm running into a problem after trying what I thought would be a simple analysis. I have 47 sites where I measured a variety of habitat characteristics (canopy cover, habitat type, percent of bare ...
2
votes
1
answer
107
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Factorial regression without significant interaction - can I consider contrasts significant?
First, I'm really sorry if this is a duplicate, I just couldn't find a definite answer.
I'm not used to analyzing categorical variables so I'm having trouble with something that is probably very basic....
4
votes
1
answer
280
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Simulating and estimating generalized mixed effects models: how to avoid convergence problems?
Basic generalized mixed effects
I am simulating data from a generalized mixed effects model
$$
P(y_{it}=1\mid x_{it})=h(\delta_0+\alpha_i+\beta_t+\gamma x_{it})
$$
where the dependent variable is ...
0
votes
0
answers
111
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How to analyze multiple choice data with logistic regression?
I have doubts about which is the best way of performing an analysis. It is the first time that I face this type of data.
Briefly, I am investigating if a number of variables are associated with the ...
1
vote
1
answer
325
views
Logistic regression with mixed effect and rare events - warning in lme4::glmer
I feel this is related to r glmer warnings: model fails to converge & model is nearly unidentifiable, and I think that the reason why the model fit fails (?) is that I have too rare events(?). ...
1
vote
0
answers
20
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How to interpret LME Estimates for an interaction effect that contains two continuous variables when one variable can be positive or negative [duplicate]
I am somewhat confused about how best to interpret the results of my logistic mixed effects model.
I have two variables, confidence (continuous, 0-100) and meta-d', which can range from -0.5-2. From ...
0
votes
1
answer
1k
views
Mixed model does not converge
I have a question regarding a mixed model I am using: In a study, participants have been presented with 40 different news article headlines and indicated for each headline whether they would share the ...
1
vote
0
answers
241
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Help in interpreting glmer and log (odds) as well as plotting my data
the statistical model I had to use for my data turned out way more complicated than I expected. I could really use some help interpreting the results. I am very grateful for any help/advice you have ...
0
votes
0
answers
92
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interpreting assumption tests for multilevel modelling
I have run a multilevel logistic regression model using the glme package in R. I now need to test the assumptions but I am not sure how to interpret the graphs I get, nor whether I'm doing the correct ...
1
vote
0
answers
34
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glmer and number of groups
I'm running a mixed effects logistic regression model with glmer in R. I have data on 1197 participants in 17 facilities, and I'm looking at survival status (dead or alive) as the outcome event. In my ...
2
votes
1
answer
1k
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Grouped/Nested data in logistic regression
Update:
Added more meaningful example data
Setting:
In my study, each of three randomly chosen readers (A, B,...
1
vote
0
answers
16
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Different identifiers for prediction with glmer
I have created a model using glmer(). The battle_seq_num is the number of sessions, each player_idhas 100 sessions (observations). My goal is to make a prediction for the test sample whether they are ...
2
votes
1
answer
900
views
How to predict ln(odds) with rcs term in mixed effects logistic model?
I am using "lme4" package to fit mixed-effects nonlinear logistic model to access the association of Y and X. As the response variable of my data is binary and nlmer function requires ...
0
votes
0
answers
168
views
how to configure nlmer/nmle for polynomial logistic regression?
I previously modeled my data with glmer and it is OK:
...
2
votes
1
answer
2k
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Mixed effects logistic regression type model in R - to use GLMER or not?
I was redirected here from stackoverflow - I'm struggling to figure out where to even put this question!
I'm doing a project where I have students listen to 7 stimuli (all students listen to the same ...
0
votes
0
answers
365
views
BinomialBayesMixedGLM does not produce same results as Lmer
I tried using BinomialBayesMixedGLM model in python to fit a logistic model with mixed effects, and for comparison, also fit a binomial model with Lmer from pymer4 library.
The fitting was done as ...
7
votes
1
answer
1k
views
Bootstrap for random effects logistic regression to get CI for difference in proportions
Let's say I have two observations of a binary variable per patient on two different treatments for a sensible number of patients, some variable like age, and I'm fitting a model like this in R:
...
3
votes
1
answer
5k
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The results of logistic regression with glmer and glm are quite different
I'm trying to analyze the longitudinal data of clinical trial.
The variables are
event: Dichotomous (1, 0) variable indicating whether event occured.
...
3
votes
1
answer
77
views
How to specify random effects in logisitc mixed effects regression with multiple observations per subject but only 1 outcome per ~50 DV measurements?
I have a dataframe that looks something like this:
Each subject got somewhere between 40-120 lesions in a given procedure, and I want to know which dependent variable was associated with "injury&...
4
votes
1
answer
3k
views
Testing glmer model assumptions (optionally in R)
I have collected binary data within subjects (multiple trials per subject) and have fit a generalized mixed effect regression to these data. My model has the following structure:
fit <- glmer(Y ~ ...
1
vote
0
answers
962
views
Interpretation of GLMM summary in R [closed]
I have serious difficulty understanding the default R-summary of a GLMM model from the lme4 package.
First of all, I would like to know how to interpret the ...
1
vote
2
answers
103
views
Looking for an interaction between dichotomous variables with paired data using glmer in R
Imagine someone sampled some chimpanzees, each chimpanzee was given two puzzle boxes to open to obtain a food reward (boxes A and B), for each case the person recorded success or failure to get the ...
0
votes
1
answer
2k
views
Contrasts in logistic regression using R
I am trying to use contrasts in a logistic regression using the lme4 package.
I have two between-subject categorical variables (both with 2 levels). The first distinguishes between groups 1 and 2; the ...
2
votes
0
answers
122
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Random effects are not centered in mixed effects logistic regression model
Random effects are usualy modelled as normally distributed with zero mean. Thus I would expect that the mean of the estimated random intercepts is close to zero. However, in my example this mean is ...
0
votes
1
answer
1k
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Different estimates for mixed effects Logistic regression and pwrssUpdate Error message with binomial glmer
Hi this is my first post here. I reported an issue on Github and got valuable help from Dr. Bolker. However, I did some other analyses on the same data and got confused about some of the results. I ...
3
votes
1
answer
2k
views
Confidence intervals in probabilities for mixed effects logistic regression
A while back I was helped to get correct confidence intervals for predicted probabilities in a logistic regression model: Correct interpretation of confidence interval for logistic regression?
Now, I ...
4
votes
1
answer
268
views
How to handle mixed-models with low sample size as well as low frequency of categorical level of interest?
Overview
I am working on analyzing data from an observational study, details of which is as follows: 18 subjects with type 1 diabetes (T1D) + 14 healthy controls were recruited for a four-week long ...
1
vote
0
answers
28
views
Help with MLM specification (data clustered by group and year) lme4 R
I have a dataset structured like so:
...
1
vote
1
answer
3k
views
Meaning of "Error in contr.treatment(n = 0L) : not enough degrees of freedom to define contrasts" when adding fixed effects to nlme?
We are attempting to model and compare logistic growth over time for 6 different treatments using nlme. So far, we have successfully added random effects of ...
1
vote
0
answers
177
views
Doubts about the use of Cross-Validation in GLMM
I've recently ask in statckoverflow about some doubts with logistic regression fitted with a GLMM and an user recommend me asking in this forum. So, here it goes.
I work with a wild population of a ...
0
votes
1
answer
1k
views
K-fold cross validation for GLMM?
hope all of you are safe during these pandemic scenario.
I would describe my case so you can get a better understatement of my question.
I work with a wild population of a bird species in which we can ...
2
votes
1
answer
3k
views
What post-hoc test should be used for a glmer model with a binary response, and a continuous and categorical predictor?
I'm a bit of a newbie with stats and R, so need a bit of direction to find a suitable post-hoc test for my glmer model. I'm trying to find if presence is affected by environmental factors for each ...
1
vote
1
answer
282
views
Optimize over theta or theta and beta in logistic mixed model (nagq = 0 vs nagq = 1)
I've been reading about item response model guides for R and my model is :
...
2
votes
2
answers
2k
views
Removing Subject Random Effect From Mixed-Effects Models & Violation of Independence
I'm running logistic mixed-effects models for a project using glmer(), but ran into a few problems with model fit.
In this model, there are 2 fixed effects:
...
0
votes
0
answers
184
views
Using glmer to analyse ratio without cbind
Say I have a stimuli (Sound from a speaker) which can either be present (Y) or not (N). I have observed arrivals of individuals and noted whether during these arrivals the stimuli was Y or N. I now ...
2
votes
0
answers
99
views
I have a proportion DV with true 0 and 1. Which mixed modelling approach (in R) is most recommend?ed?
Hope this isn't too much of a dumb question. I've been searching for a definitive answer, and now I've got choice paralysis.
I have a proportional DV (accuracy) with true 0 and 1 values averaged for ...
1
vote
0
answers
292
views
Back-transforming coefficients of glmer model fit using rescaled independent variables for prediction & plotting
I've fit a model using the glmer function from the lme4 package. Because my predictor variables are on very different scales, I ...
0
votes
1
answer
2k
views
Why am I encountering Error: Response is Constant, when using performing a GLMM using glmer?
I am trying to determine what factors best predict/explain where deer fawns are being killed by predators based on the kill site's distance to clear-cuts (which I've grouped into three different age ...
2
votes
1
answer
568
views
xtmelogit vs. glmer different results
My dataset (long format) contains of data collected in 4 studies. Although the variables in the studies were identical, I want to account for the substantial heterogeneity of the populations between ...
1
vote
1
answer
626
views
Multilevel logistic panel regression with glmer in R
My dataset (long format) contains of data collected in 4 studies. Although the variables in the studies were identical, I want to account for the heterogeneity of the population between these studies ...
1
vote
1
answer
328
views
Handling cumulative exposure variables in mixed-effects logistic regression (MELR) models
I am working on analyzing the results of an observational study, a brief description of which is as follows:
X number of diabetic subjects have been recruited to collect naturalistic driving data, ...
7
votes
1
answer
6k
views
Specifying model in glmer() - interaction terms
I am running a generalised mixed effects model, of family logistic regression, using function glmer().
I am predicting likelihood of response (0/1) and my fixed effects to explore in my final model ...