Questions tagged [random-intercepts]
The random-intercepts tag has no usage guidance.
13 questions
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LMM: effect of day may differ between subjects - fixed or random effect?
We tested 12 animals in a test with three phases (a/b/c) in three conditions (C1/C2/C3) on nine days, i.e. every animal experienced each condition three times. On each day, four animals were tested in ...
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Random intercept model equation with two-way interaction and extra control measure
I'm trying to figure out how I should express the following model in an equation.
The outcome is repeated 30 times within each individual, so 30 trials per individual of a certain measure (trials). ...
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Intercept calibration in logistic hierarchical regression model
i am following Debray et al. 2013 (A framework for developing, implementing, and evaluating clinical prediction models in an individual participant data meta-analysis) to estimate a risk prediction ...
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Estimate random effect variance for power analysis in multilevel model
Is there a general convention on what variance to expect for a random intercept in a multilevel model? I need to provide an estimate for the power analysis. It is a within-subjects design. Thanks!
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Random intercept
I have the following model, how do I add a random intercept(no random effects included yet):
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Random Intercept vs. Random Slope Linear Mixed Effects Model with Nested Data
I have read a lot about random intercepts vs. random slopes in linear mixed effects (LME) models, but I am confused on how to think about them when it comes to nested data. I have looked at other ...
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How can I fit a least absolute deviation model with random intercepts?
I have some data and a model formulation that I believe describes the data generating process. The model looks like this
$$y_{i,t} = \beta_1x_{i,t} + \beta_2x_{i,t-1}+\alpha_t+\epsilon_{i,t}$$
where $\...
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Variance of conditional mean estimates obtained from a mixed model/multilevel model
Assuming I have observations nested in groups with varying (true) means. Using a random intercepts mixed model (multilevel model), I can estimate the variance of these random intercepts. Additionally, ...
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Does adding a random intercept for subject address confounding variables within subjects (e.g. sex or age)?
Let's say I am interested in identifying associations between a blood protein and disease activity, but I have multiple measurements per subject. Based on a literature review, I expect sex differences ...
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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 ...
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Add covariates to the random-intercept mixed effect model
I'm working on a study where I want to explore whether two covariates, let's call them C and D, can help explain the differences we observe in our dependent variable, which we'll call B (depression ...
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RI-CLPM - Testing whether between and within effects significantly differ
I am currently using a random intercept cross-lagged panel model (RI-CLPM; Hamaker, 2015) to assess between and within effects. For the same variables, we find a negative relation at the between level ...
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In my mixed effects model, are the confounded MCMC chains between my random intercepts and my global intercept problematic?
I implemented an MCMC algorithm for the following regression model:
$$y_i \sim N(\mathbf{x}_i'\boldsymbol{\beta} + \eta(\mathbf{s}_i) + \theta_i,\sigma^2),$$
$$\boldsymbol{\beta}\sim N(\boldsymbol{0},...
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