Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [interaction]

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

"Interaction" refers generally to when the effect of an explanatory variable depends on the value of another explanatory variable. In the simplest case, in linear regression, that is analyzed by including the product between two variables as an additional predictor in the model. This implies that the slope of each variable depends on the value of the variable it is interacting with.

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Interaction between ordinal and categorical factor

What analyses can be used to find an interaction effect in a 2-factor design, with one ordinal and one categorical factor, with binary-valued data? Specifically, are there any types of analyses that are capable of dealing with a 2 factor design…
mpacer
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Why does adding statistically significant interaction reduce true positives?

I am trying to increase my model accuracy by taking into account interaction effect of relevant variables. I am choosing variables to interact based more on the common sense than on trying every combination. So far most interaction effects with…
ayush biyani
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How to interpret when insignificant 2-way interaction terms made variable of interest insignificant?

I want to test whether a treatment (=1 if treated, else 0) have effect on participant $i$'s outcome $Y$. The coefficient $\beta_1$ is significant in the main model: $$Y_i=\beta_1 treatment_{i}+\beta_3 sex_{i}+controls_{i}$$ But the coefficient…
Key
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Interaction term based on continuous variable or dummy?

I'm interested in the linear relationship between $Y$, $X$ and an additional control $C$, all of which are continuous. I expect that the effect of $X$ on $Y$ is different for different levels of $C$. Thus, I see the following possibilities of…
bonifaz
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When is a moderator effect not an interaction effect?

MacKinnon (2012) writes on p11 that A moderator is a variable that changes the sign or strength of the effect of an independent variable on a dependent variable. It is typically (but not always) an interaction such that the effect of an …
user1205901 - Слава Україні
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Interaction term significant but in the plot the lines don't intersect

I tested the moderating effect of the variable X' on the relation between X and Y. The results were positive and significant. However, when I plotted the results, I found out the two lines become very, very close at the higher levels, but do not…
YoungResearcher
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Process Macro SPSS-Moderation Analysis with 2 Predictors and 2 moderators

I've been trying to learn how to do this analysis but I can't find any information that sheds light on my case and I can't figure out what to do from Hayes' book. I would really appreciate it if someone could help me out. For my undergraduate…
Demi
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How can the pooled slope be outside the sample-specific slopes

I have a data set with a continuous LHS variable y, continuous RHS variable x, and a dummy D. I am running two OLS regressions: $$y_i=\beta_0+\beta_1*x_i+\epsilon_i$$ and $$y_i=\gamma_0+\gamma_1*x_i*(D_i=1)+\gamma_2*x_i*(D_i=0)+\eta_i$$ My estimated…
lippi
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Interaction vs adjusting?

I've tried searching but came up short as this is probably a very generalized question, but it goes: What is the difference between an interaction term and simply including (adjusting) for that same variable in a regression model? Example: We have…
Paze
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Right approach when the values of a predictor might differ for repeated measurements?

We took 2 samples (sweep netting) of bee communities on 30 vegetable fields at 2 time steps (during early flowering and shortly before harvest). After the vegetables were harvested we asked the farmers how often they applied pesticides. Now I want…
Arne
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interpreting moderation interaction versus main effects

Moderation interpretation when one predictor is insignificant? My moderation analyses is testing whether self-compassion moderates the relationship between pain severity and emotion (negative and positive, separately). In this moderation, pain…
Mel
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Is it acceptable to remove a main effect in an interaction model where the variable is only populated for a treatment group?

I am trying to construct a model to predict how a treatment will affect new units in the presence of certain covariates. For purposes of explanation, let's suppose the units are bacterial colonies and the treatment is the application of heat. The…
JSMInspiredMe
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How to interpret interaction between a dummy and a continuous variables in ols?

I am trying to examine the association between maternal education and child school test scores using the following equation. $$\small{TestScore_i = \beta_0 + \beta_1 EduYrMom_i + \beta_2 FemaleChild_i + \beta_3 EduYrMom_i * FemaleChild_i +…
Monzur
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creating interaction term for dummy variables and categorical variables

I want to create interaction term by using dummy variables and categorical variables. For example, if I want to create interaction term by gender(0=male, 1=female) and education level(0=less than elementary, 1= middle and high school, 2= college or…
user62538
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Simple Slopes Analysis (centering variables +1/-1 SD from the mean)

I am investigating a moderator relationship after a significant interaction between two centred variables. Using simple slopes analysis I want to see the effects of high/low scores of one variable -1/+1 SD relative to the mean on another predictor.…
Max Moser
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