The mixed-effect tag has no wiki summary.
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78 views
ANCOVA (GLM) versus Mixed Linear Model with covariate measured at both pre- and post-treatment (in SPSS)
I'm trying to analyze a pre/post study with 4 treatment groups. The Dependent Variable, Speed, measures how quickly a person's facial expression reaches peak intensity; this measure is normally ...
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147 views
Using lme4 for case-controlled logistic regression?
I would like to use lmer for a conditional (or case-controlled or matched pairs) mixed effects logistic regression. However, I am not aware of any published use of ...
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35 views
Modeling threshold effects
First, let me give some context for my question.
I'm working on a project in which our research team implemented a workshop intervention at a number of different departments at my university. Each ...
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1answer
181 views
Likelihood ratio tests on linear mixed effect models
I am currently running some analyses on a linguistic data set with a mixed effect model. The problem is, I think that one random factor should be excluded while my colleague thinks it should be ...
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1answer
190 views
Linear mixed model with lme - time as fixed categorical variable and random slope?
I´m still new to statistical modeling and quite confused about how I should correctly specify my model.
I have 3 crossed categorical treatments - stress, infection and food. Each individual was ...
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1answer
34 views
Missing values in GLMM
I am creating a GLMM based on a experiment where each subject has 2 repeats. In some instances though there is only data for one of a given subjects repeats for most there is data for both. Can I ...
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278 views
Step-by-step mixed model analysis in R using lme, ezANOVA, or aov
My data consist of 4 treatments (fixed), 8 locations (2 locations per treatment), 3 positions (per location, fixed), 3 samples (per location, random), with dependent variable ...
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46 views
NLME regression & curve comparison
I have two groups (patients & control) and each person was measured 3 times.
I use the nmlefitsa function of MATLAB for doing a regression over time for these ...
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1answer
198 views
Proper bootstrapping technique for clustered data?
I have a question regarding the proper bootstrapping technique to use with data where strong clustering is present.
I've been tasked with evaluating a multivariate mixed effects predictive model on ...
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2answers
405 views
Regression with repeated measures in Matlab
Is there a way to perform multiple logistic regression on repeated measures data using Matlab?
I have a data set containing a daily measurement recorded from 20 participants for 60 days. I am ...
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1answer
63 views
Posterior density of nonlinear random effects
Consider the nonlinear mixed effects model for the $j$th observation $y_{ij}$, $j=1,\dots,n_i$, $i=1,\dots,N$, of individual $i$ at time $t_{ij}$ :
$$
y_{ij} = f(\alpha_i, t_{ij}) + g(\alpha_i, ...
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1answer
141 views
Matlab tool for nonlinear mixed effects
I'm wondering if someone is familiar with the NLMEFITSA algorithm in matlab. This algorithm gives me as result the fixed effects parameters (beta) for a mixed effects model as well as their covariance ...
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51 views
Difference between kappa and delta in mixed-effects model
I have a following stochastic model describing evolution of a process (Y) in space and time. Ds and Dt are domain in space (2D with x and y axes) and time (1D with t axis). This model is usually known ...
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1answer
604 views
Understanding the output of lme
I am having some difficulties interpreting the results of an analysis perfomed using lme. I conducted an experiment where the subjects had to estimate the time elapsed in a task involving a spatial ...
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90 views
How to quantify moderation effect in an intervention study with multiple time points?
I want to measure a moderation effect between 3 continuous variable in an intervention study. I am using scores from self-report measures of masculinity, emotionality, and psychological distress. The ...
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0answers
61 views
How can I test for significance of a treatment in an unbalanced, repeated-measures experiment using R?
CrossValidated Community,
I must mention that I am a first-time poster (and relatively new to both modelling and R), so please excuse any norms I may violate in my post and politely inform me.
I ...
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2answers
722 views
Random effect equal to 0 in lmer in R
Sorry if Im missing something very obvious here but I am new to mixed effect modelling.
I am trying to model a binomial presence/absence response as a function of percentages of habitat within the ...
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1answer
356 views
Proper use of weights argument in linear mixed model [lme()]?
After attempting to produce a linear mixed model I was left with a great deal of heterogeneity.
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1answer
277 views
Should I keep or remove random effects?
After attempting to produce a linear mixed model, I was left with a great deal of heterogeneity.
...
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0answers
81 views
Group-level correlation effect
I am measuring two continuous variables (X,Y) for 21 subjects. X and Y have 216 data points each (per subject). I would like to see if X and Y are correlated at the group level. I can think of 3 ...
