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A situation where the effect of an explanatory variable may depend on the value of another explanatory variable.

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1answer
10 views

Log-transformed DV and coefficient of interaction term

I am having difficulty interpreting the significance of positive tone (measured as percentage of words in a sentence that are positive in tone) for females and males. The following is the regression ...
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1answer
22 views

GLM - interacting predictors for which the mediator only applies to one type of outcome

I am running a simple GLM with an interaction of the two main predictors. The outcome (dependent) variable is binary and takes the value of 1 when the product is ...
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0answers
23 views

F statistics and relative significance

I have some f-statistics that came from an ANOVA (1 df in numerator and 60 df in denominator) : (first row should be labeled "H," second row labeled "S.") ...
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0answers
13 views

Interaction between covariate and 2-level within-subjects factor is of research interest. How to test

I'm interested in interpreting the interaction between a continuous variable (C) with a dichotomous within-persons factor (A) on a continuous DV (DV). What is the best overall test of this? Would it ...
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0answers
34 views

Interpretation and practical significance based on multiple linear regression coefficients

I am having difficulty articulating the practical significance of positive and negative tone in job application cover letters for male and female job candidates. I obtained the following linear ...
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0answers
16 views

Different significance in GLMM interactions

I am confused about different significance results obtained in GLMM's. First, my set of relevant variables: ...
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0answers
14 views

Interaction of categorical variables [closed]

I would like to interact two categorical variables: agecat and female regress income i.agecat#i.female This will give me all combinations agecat (1-10) and ...
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0answers
12 views

Accounting for Interaction between Independent variables

Is there some trustworthy resource on effect of interactions if not accounted for. Especially the situation is often, let's assume heart surgery, age, gender and logistic euroscore(derived from age ...
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1answer
40 views

GAM interaction- how to interpret

I am working with a GAM model (based on a negative binomial distribution): model_n = gam(y ~ x1 +x2+ x3+x4 + s(x5)+x6+s(acc, by=ses)+x7+x8+ x9+x10, data=totalfinals, family=negbin(3)...
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0answers
18 views

Categorical variable interaction compared to individual regressions

We are examining our understanding of interaction terms in categorical variables. We have a three category variable, and the model is: $y=\alpha+\beta x+\beta_0x_0+\beta_1x_1+\beta_2xx_0+\beta_3xx_1$ ...
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0answers
11 views

2SLS IV with endogenous interaction in Stata: Difference between ivreg2 and manual estimates

I want to estimate 2SLS in Stata with two endogenous, continuous variables: $X_1$ and the interaction term $X_1*X_2$. The other IVs $X_2...X_N$, including the quadratic $X_2^2$, are all exogenous. I ...
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1answer
17 views

Two-way interaction term and simple slope

In my study, I am looking at gender interaction with an independent variable. In the fitted linear regression, if the gender*var1...
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1answer
26 views

How to properly test simple effects: factor recode or data subsetting

I have seen people test their simple effects in two different ways and would like to know which is the correct one and why. The two methods are briefly explained below: recoding method: Involves ...
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0answers
13 views

How to do simple slope analysis for interactions in zero-inflated negative binomial regression in r?

I used the function 'zeroinfl' from the 'pscl' package to fit a zero-inflated model with negative binomial distribution (zinb). Results show significant interaction effects and I should do simple ...
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0answers
4 views

Option-specific interaction in multinomial logistic regression

I have an experiment where people choose between 5 options; half of the people make this choice in condition A, half make it in condition B. I know that people become more likely to choose option 1 in ...
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1answer
21 views

Log response ratio of means not agreeing with linear mixed model output

I have a linear mixed model structured like so: Richness~Time*Treatment+(1|Site) Time has two levels (Pre and Post) as does Treatment (Treatment and Control). ...
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1answer
72 views

How to evaluate all possible contrasts of an interaction effect

Let's say I have an experiment where I pair people up with either individuals of the same political orientation, or different. I track before and after measures of a respondent's belief in global ...
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1answer
31 views

What's the most intuitive way to decide if interaction exists between 2 categorical variables in regression in R?

To discern interaction between categorical and numerical variable, one can look at the slope change. What's an intuitive visual way to detect or deny interaction between categorical variables? ...
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1answer
13 views

Testing for interaction between two categorical independent variables and a dependent variable

This is a contrived example for clarity, but it reflects a real problem that I'm dealing with: Say that I want to analyse miles-per-gallon (ratio) for cars of different color and interior type (both ...
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1answer
36 views

Difference-in-difference effect with triple interaction

I added an image of the regression output I could use some help with, as I am trying to recreate this but with data from a different time period. This is the result of a difference-in-difference ...
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0answers
36 views

The right statistical method to measure a complex synergy

In order to measure multidimensional effects, it can be common to compute a score, as a combination of unidimensional factors. For instance, one could compute a score ...
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3answers
64 views

Examples where A increases with increasing B or C, but decreases when both B and C are increased together

I have a vague memory that this relationship is possible, but I can't think of any examples off the top of my head. Is there a canonical or common example(s)? I am imagining that in two independent ...
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0answers
32 views

Regression using interaction term or create variable with multiple levels?

I have a large dataset (n=10,000) where I am looking at effects of health on blood pressure, Y. I have 4 age groups (50-59) (60-69) (70-79) (80-89) and have divided each age group into 'health ...
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0answers
12 views

Interactions in regression with two categorical variables

Hopefully somebody can help me or point me in the right direction! I've done a study comparing the effect of a training on a continuous dependent variable, let's call it symptom severity. The study ...
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0answers
23 views

Which statistical test to determine interaction effect?

I conducted an experiment to determine the effect of blood type on blood cell interactions with proteins of differing blood groups and want to determine if there is an interaction effect for the ...
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1answer
11 views

interaction between 4-level categorical variable and a continuous moderator

I'm trying to find a way to investigate whether religiosity correlates positively with helping other people, and whether this correlation is different depending on a 4-level manipulation (in my design,...
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1answer
33 views

Linear Regression: Why do the coefficients change on the original IVs when you interact them, and add that new interacted-variable to the model?

Basically I want to know how the 'constant' value differs in each of the following models: Model 1: DV=income; IV1=gender (0=male, 1=female); IV2=location (0=east, 1=west) Here, I understand the ...
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0answers
11 views

How to interpret interaction in ordinal regression?

I have two continuous independent variables and a 5-level dependent variable. The p-value for the interaction term is small. How to interpret or visualize?
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0answers
20 views

Logistic regression with 3x4 categorical variables and interaction effects

I am trying to analyse a logistic regression model based on categorical data in a 3 x 4 matrix with both main and interaction terms. The output data i get is along the lines of this: My main ...
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1answer
35 views
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0answers
14 views

How to Interpret Co-Linear Interaction Term?

I am looking to model transit ridership based on demographics at the stop level. For each stop, I know: ONS: Total boardings per day - averaged over the number of times a bus pulls up at the stop ...
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1answer
23 views

Interacting treatment variables with independent variables in matched samples

Can we interact the treatment variables with independent control variables that have been used for matching? I have a binary treatment variable called 'medicine'. It indicates whether a person ...
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2answers
50 views

Why and how does adding an interaction term affects the confidence interval of a main effect?

I was wondering why, in a regression model including an interaction term, the confidence interval of one of the main effects becomes wider. Consider this Cox regression, where the variable IR_BMI27 ...
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1answer
29 views

What is a reference level for an interaction of categorical variables in glmer?

I want to see whether there is an interaction effect between "session" and "structure" on participants’ accuracy. For this I run a glmer model: ...
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0answers
43 views

Simple main effects - R

This is a simple question yet I cannot find a definitive answer anywhere. When running a two-way anova in R, I get a significant interaction. I am aware that because the interaction effect was ...
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0answers
23 views

How to conduct a moderated multiple regression with two (or more) moderators?

I've been trying for a while to understand how to perform this type of analysis, but I can't seem to find any literature or even forum posts about it, so any help or guidance anybody can offer would ...
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0answers
6 views

Manage covariance, multiple regression, moderated regression

I am having a huge problem with my stats. I am working towards a predictive model. I have 8 continuous IVs, 3 potential categorical IVs (2 of whom I had to compute into dichotomous), and 8 continuous ...
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1answer
23 views

Main effect insignificant: should I estimate an interaction with it?

As the title reveals, does it make sense to estimate an interaction when you already see that a main effect is insignificantly different from 0 in regression? In my study I am actually interested in ...
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1answer
36 views

Moderation in R: Plot moderation for regression model with one interaction and controll variable

I'm testing a moderation using R and would like to plot it. This is my regression model (2 predictors + interaction): ...
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0answers
3 views

Can a moderating variable be a single dimension of a multidimensional main effect variable in interaction?

I am stuck on an empirical issue. I would like to test whether a single dimension of a multidimensional main effect variable strengthens or weakens (moderates) my main relationship. But, the ...
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0answers
6 views

Is there any way to assess interactions on an additive scale for a matched case control study with a binary outcome?

The outcome is work disability and the cases and controls are matched 1:1
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1answer
23 views

Modeling interaction between state and action in Reinforcement Learning with Function Approximation

This is a question that has been bugging me for some time: if I'm designing a RL algorithm to find the optimal value-action function Q(s,a), and I want the optimal action to depend on the specific ...
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0answers
27 views

Should I restate my hypothesis? (interaction)

Suppose I have the following model: $Y = α + β1∗education + β2∗gender + β3∗gender∗education$ Gender = 1 if male (reference group = 0 female) Based on the theory I develop the following two ...
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0answers
20 views

Is a three-level multilevel model appropriate for my research question?

For a study that is currently in the planning stage we are considering what kind of model would be most appropriate. We are interested in the interactive effect of a drug (vs. placebo) and hormone ...
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0answers
14 views

Interpretation of negative interaction term?

I have two dummy variables that measure whether a woman has children and whether a woman has a son. They are both positively associated with my outcome variable, however, I get a negative moderating ...
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0answers
14 views

reporting beta coefficient for chunk tests in logistic regression

I have used lrm in the RMS package to construct a logistic regression model with several interaction terms for a recent paper. As part of my strategy, I decided to use Wald Chi-squares on factors ...
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1answer
36 views

How to chose covariates to adjust for in a regression analysis

I am running a regression analysis where my primary interest is to see if the outcome differs by the group (treatment vs. control). However, I have some 80 other clinical and socio-demographic ...
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0answers
28 views

What is the b statistic reported in a t-test?

For more context, this is what was reported in the article .. "In support of our hypothesis, we found a significant three-way interaction for [..the dependent variable..] (b =.22, SE = .10, t(417) = 2....
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1answer
89 views

3-way ANOVA with a significant 2-way interaction. What are my next steps?

I have performed a mixed 3 way ANOVA: Group (2 levels) x Factor2 (2 levels) x Factor3 (2 levels). There was no significant 3-way interaction; however, there was a significant 2-way interaction ...