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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1answer
28 views

Interpret contradicting output of lmer model with categorical interaction in R

I am struggling to interpret my output in R. It does not make sense to me. I first regressed participants' ratings (= value) on manipulations (...
1
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1answer
100 views

Computation and interpretation of marginal effects in a GLMM

I am currently working on a GLMM model which uses a Poisson distribution and need to compute and interpret marginal effects from this model. The model outcome consists of a count (COUNT) collected ...
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1answer
27 views

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 ...
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0answers
28 views

Set different link functions in Generalized Mixed Effects Model in R

Suppose I have a dataset of fish, some are salmon some are trout. I have a bivariate regression model specified roughly like below: prob(caught) = 0.5 + 0.5 * logit_inv(diet + fish_type) for salmon ...
3
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1answer
336 views

Calculating confidence intervals of marginal means in linear mixed models

I'm using different R packages (effects, ggeffects, emmeans, ...
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0answers
15 views

How does R handle standard errors for fixed effects regression with partially time-invariant regressor?

I'm running a fixed effects regression in R, with four FE strata. I have an independent variable, x, that varies within two of the strata, but is invariant within the other two strata. My ...
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1answer
690 views

Differences between Simple Effects, Pairwise Comparisons, and planned/post hoc comparisons?

I am very confused as to the differences between simple effects, pairwise comparisons, and planned/post hoc comparisons. From what I understand, after running an ANOVA, you would use one of these to ...
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1answer
59 views

Why does it not make sense to compute effects for lower-level interactions in the absence of higher-order interactions?

The documentation of effects package says "If asked, the effect function will compute effects for terms that have higher-order relatives in the model, ...
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1answer
28 views

Macroeconomic effects. Effects of a time serie on another

I have a monthly time series for the provision in a financial institution. Take real data until december 2017 and predict it with a Bat model until June 2018 using R and I have an error of 0.12%. This ...
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0answers
250 views

random intercept, random slope plus intercept, no random slope alone? [closed]

I measured running speed of 70 individual lizards. The lizards were siblings born of 7 mothers, 10 offspring each. The Lizards ran at 3 different temperatures, A, B, and C, where A < B < C, and ...
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1answer
101 views

Different standard errors under Mac and PC in “effects” R package [closed]

I ran a model with lme4::lmer() on my Mac, then predicted values and standard errors of the interaction with effects::Effect(). Then I tested the same code under Windows. Everything was identical ...
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1answer
107 views

How to simulate R data for a random effects model set-up?

Suppose we have $m$ schools chosen randomly from among thousands in a large country. Suppose also that $n$ students of the same age are chosen at each school. Let $Y_{ij}$ be the score of the $j$th ...
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0answers
530 views

Effect plot with lme model

I am building a mixed-effects model with nlme package. The output of the model is as seen below, and includes the time variable, namely day and one categorical variable for treatment with 4 ...
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0answers
784 views

Conditional effects in a multiple regression model

I was told that if I have a regression model $Y=b_0 + b_1X + b_2Z + b_3(X *Z)$, coefficients $b_1$ and $b_2$ have conditional effects. What does this mean exactly? How do I know when I have main ...
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0answers
235 views

Panel data ID and time level fixed effects with propensity score matching possible?

I have about 15000 observations on long term care centers per year, for a period of 10 years. My independent variable is binary and the outcome variable is continuous. I have performed ID and year ...
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0answers
73 views

Comparison of coefficients in fixed effects vs. non fixed-effects regressions

I recently came across a paper that runs pairs of regressions, in which one regression includes unit fixed effects and the other regression does not include unit fixed effects. The paper then ...
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0answers
31 views

Mixed Effects: How to Account for (Complicated) Interdependency Nested within Trials?

This is an issue I've been discussing in-depth with with my stats tutor without being able to figure it out. I am very, very grateful for any useful insight. Core Question: In each trial, ...
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1answer
70 views

Saving plot .pdf to working directory in R for a Mac [closed]

I am working on a MacBook Pro OSX 10.12.5 and R 3.4.0. I have run a simple linear regression (and lmer plots, but one step at a time) utilizing the effects package. It is a common issue that R will ...
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0answers
224 views

2x2x2 (reduced) design to study main effects

I'm at the point of conducting a 2x2x2 factorial design to study corporate adoption decisions. I am only interested in the main effects and run a ANCOVA. This experiment is only one part of a bigger ...
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0answers
138 views

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 ...
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0answers
339 views

Identification with multiple fixed effects

I have been thinking about this question for a long time: I wanted to ask that if we have a fixed effect regression (say data on 30 counties over 10 years). Now, say I run a regression $Y_{it} = \...
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0answers
54 views

Why do we use random effects model to consider clustering effect?

It's hard to get a grasp on the intuition on the random effects model. As I understand, to summarize, we use random effects model when we wanna regard the variable as drawn from a population, rather ...
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2answers
68 views

Reasons for weak multiple regression

1) Could you enumerate few main reasons for weak (statistically non-significant, like p > .05) results ? After running multiple regression analysis. 2) There is one construct, which plays a role of a ...
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1answer
444 views

R 'effects' plot - dichotomizing variable with 'xlevels' with cut-off-values

lets say I want to dichotomize a previously continuous variable (e.g. Age) of a mixed-effect model (lme4) into two levels directly in the effects function in R (Age ...
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1answer
63 views

SPSS Moderating Variable Confusion

I have done an online survey for my dissertation and now I am a little bit confused: I tested the following model: Variables A -----> B (Variable A negatively correlates with Variable B). Moderating ...
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2answers
32 views

In the case described below, should regression coefficients be reported?

I am conducting a simple moderation analysis with a continuous predictor X, an ordinal moderator M, and a continuous outcome Y variable. X was found to have a significant effect on Y, but M did not ...
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1answer
21 views

How to strip out multiple effects from a metric?

When users report "Support Contacts" metric in the monthly meetings, sometimes it is decreasing and that can be caused by our operations like agent training (good thing), and sometimes it is ...
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0answers
70 views

Logistic regression: Significant difference inbetween marginal effects

I was wondering how I could check if the calculated marginal effects within a logistic regression are significantly different from each other. Is it sufficient to check if the corresponding Beta-...
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0answers
106 views

Using effects package with clustered covariance matrix [closed]

I'm using R to plot interaction effects after a linear model. I'd like to plot an interaction effect with an error ribbon using the "effects" package. However, I want to calculate errors based on a ...
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0answers
142 views

Nesting within a crossed mixed effects model necessary?

I have data from a repeated-measures experiment to analyze. In the experiment, 67 subjects gave ratings for 50 stimuli (different screenshots), all of them shown three times in distinct durations (as ...
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2answers
903 views

Should I use logistic mixed effects? How?

I've run an experiment in which different subjects had to make a number of decisions, which are stored in the dependent boolean variable Y (0 or 1). I have multiple independed variables which may ...
4
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1answer
679 views

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 ...
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0answers
607 views

Reporting Results from a Mixed ANOVA

I have done a Mixed ANOVA on some data from a tennis serving experiment and am slightly confused on how to report the results. I am comparing the effect of self-talk (either instructional or ...
34
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2answers
23k views

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 ...
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1answer
26 views

Find the effect of a attribute value on an outcome by eliminating confounding values

I have a series of lets say five attributes. The first attribute is called diagnosis code 1, the second diagnosis code 2 etc. The values are codes which represent diseases. In other words, each ...
2
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1answer
957 views

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 ...
4
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2answers
79 views

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 ...
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0answers
49 views

Is a mixed/ random effects model required if fixed effects model shows no pattern in the residuals?

I've got some data on discrete flood events (response variable - duration) on several rivers. I've modelled the response variable by site and time using a Generalized Linear Model: ...
2
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1answer
306 views

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>...
2
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2answers
92 views

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 ...
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1answer
48 views

Compare mean effect of one predictor based on another predictor

I would like to compare the effect of one IV ("sensation seeking") on a DV ("intended infidelity") based on another IV ("gender"). Actually I really just want to compare the means. So I would like to ...
2
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1answer
304 views

Making various mixed effects models

I've tried to create three models (using R): an intercept only linear regression, a simple mixed effects regression and a by-subject effects mixed effects regression. An intercept only regression ...
3
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0answers
1k views

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 $\frac{dy}{dx}$....
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0answers
30 views

interpret Alleffects() from effects package [duplicate]

I have this example logit model where some of the variables are factors but I'm not too sure how to interpret the effects. If I understand logit models correctly the coefficients that we get from the ...
5
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2answers
6k views

Difference between a 2 factor ANOVA and mixed effects model

The lme4 package in R includes the cake dataset. ...
2
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2answers
885 views

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 ...