Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [effects]

An R package for calculating graphical and tabular effect displays, e.g., of interactions, for various statistical models with linear predictors

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How trustworthy are the confidence intervals for lmer objects through effects package?

Effects package provides a very fast and convenient way for plotting linear mixed effect model results obtained through lme4 package. The effect function calculates confidence intervals (CIs) very quickly, but how trustworthy are these confidence…
Mikko
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Difference between a 2 factor ANOVA and mixed effects model

The lme4 package in R includes the cake dataset. library(lme4) head(cake[,2:4], 20) recipe temperature angle 1 A 175 42 2 A 185 46 3 A 195 47 4 A 205 39 5 A 215 …
luciano
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Calculating confidence intervals of marginal means in linear mixed models

I'm using different R packages (effects, ggeffects, emmeans, lmer) to calculate confidence intervals of marginal means in a linear mixed model. My problem is that the effects package produces smaller CIs compared to other methods. Here is an…
Han Zhang
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Reporting the Actual Formula/Equation of an LME model (with factors) used in R?

I have a dataset that has measurements of resource consumption in buildings for a number of years. I am interested in the differences in resource consumption of buildings in my study area between years (as opposed to differences between individual…
Robin_H
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How can I calculate the effect of my equipment on my sport's performance?

I'm doing a stationary sport like golf, so the details matter. I'm recording each of my scores with detailed information about the equipment I'm using, and the weather conditions. So 1 score has 2-3 pieces of equipment attached to it. I can plot…
Andrei Erdoss
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Marginal effect clogit not significant

I developed a conditional logit model in Stata. The model is good and the variables are highly significant. Then I do mfx predicted (PU0) to determine the marginal effects of variables $\frac{dy}{dx}$. The problem is when I get the table of the…
mina
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Should a mixed effects model be used?

This post provides an excellent example of the inner workings of a mixed effects model: http://emhart.github.com/blog/2012/11/16/making-sense-of-random-effects/ In a hypothetical study, I have measured the wing length of a bird species at 10…
luciano
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Random effects and random errors

Let's say that we have this simple model: \begin{equation} \label{eq:gls_reg} y_{ij} = x_{ij}\cdot\beta +{u_{i}} + \varepsilon_{ij} , \end{equation} \begin{equation*} u_i\sim N\left( {0,\sigma_{u} ^2 } \right)…
Noob
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Mixed effects logistic regression formula with one random effect

In our thesis, we have used a mixed-effects logistic regression and now we want to present it as a formula, however, we are not sure how to present a mixed-effects logistic regression? Our binary outcome is if the calf of a specific age group is…
Isabella Francis
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What do I do when my model prediction exceeds the limit of 100%?

I have plotted the effects of a model glm( A ~ B, family=poisson, data=data) both with the sjplot R package and with the effects package. However, my A variable is a percentage (min=0, max=100) and the effect plot shows A values higher than 100.…
Sara
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How to interpret effects of predictors with large confidence intervals in GLMM?

(This question is somehow related to my previous one) My aim is to find out about which effect several predictors have on my response variable, I am interested in the direction and magnitude of the effect. I am wondering how I should evaluate the…
user45065
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Mixed Effects Model Random Effect Confusion

currently I am trying to build a model as part of a research project assessing threats to ecosystems. I have used mixed effects models before but the random effect was contributing a lot to the variance then so it was easy to leave it in. I can't…
Miles
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Is including the main effect of the covariate enough?

Is simply including a covariate in a model (ANCOVA) enough for variance in the DV due to it to be factored away? Or do the higher order interactions of the covariate with the other factors of the model have to be modelled as well? In some software…
z8080
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Interaction wipes out my direct effects in regression (non zero variable)

I have the following regression $children = \beta_0 + \beta_1 \log(earnings) + \beta_2 grandparents + \epsilon$ and $\beta_1>0$ with $p$=0.01 and $\beta_2>0$ with $p$=0.01, and N is large (N>10.000) and grandparents takes values 0,1,2,3,4. Then I…
pin_gu
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Decaying effect of IV over DV. How to analyze?

I need to prove my hypothesis: The relative impact of the direct ties on the project outcome decreases as the direct ties network grows. So I have IV (network size) and DV (outcome). I have proved by regression that IV is a significant predictor…
Delyan Peyankov
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