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

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10 views

Identifying repeat interaction from two columns [migrated]

I have two columns which contain investment bank names in joint debt offerings. I want to create a dummy variable if the Bank 1 & Bank 2 have recurring relationships. Ex: if Lehman Brothers ...
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1answer
34 views

R adds unexpected variable to interaction model

Not sure if this is more of a programming question (in which case please move to stack overflow) or a statistical model question (in which case, please read on!) I'm exploring a data set and doing ...
2
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1answer
25 views

Interaction effect of 2x2 ANOVA in meta-analysis

I want to meta-analyze the interaction effect of a 2x2 ANOVA. (I am not talking about an interaction in the meta-regression, as in this question but about an interaction as the focal effect that ...
0
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1answer
21 views

Dropping the interaction term when the interaction effect is not significant?

Can I drop the interaction term from the model if the interaction term is insignificant?
0
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1answer
11 views

main effects of moderating variables

I am sorry if this is very trivial and a repetition. I could not find a direct question on the website that addresses my question I am studying the relationship between X1 (independent variable) and ...
0
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0answers
16 views

Can I interpret a simple slope if the product is not significant?

I used Hayes' PROCESS macro to run a simple regression. The interaction product was not significant (p=0.13) however the conditional effect (simple slope) was significant (at high levels of the ...
1
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1answer
44 views

Investigating interaction

Please I need to check for interaction before building an explanatory model (logistic regression). I have 16 interaction terms in total. Please how what is the best way to go about it. Will I need to ...
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3answers
46 views

Testing and reporting interactions in multiple regression

I have a model with two between-participants predictors -- one continuous (a), and one categorical with two levels (b) -- and ...
7
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2answers
81 views

How should I model interactions between explanatory variables when one of them may have quadratic and cubic terms?

I'm sincerely hoping that I have phrased this question in such a way that it can be definitively answered--if not, please let me know and I will try again! I should also I guess note that I will be ...
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0answers
22 views

Interaction with contrast and dummy coding

I have a question regarding the interpretation of an interaction using categorical variables where one is dummy coded (0, 1) and the other is contrast coded. The variables are: Var1: 3 levels, ...
0
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1answer
34 views

regarding the explanation of interaction plot

I was trying to draw an interaction plot for two predictor variables as follows: interaction.plot(xtest[,2],xtest[,8],y) I got the following plot. I do not know ...
1
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1answer
22 views

Interpretation of significant interaction

I look for an intuitive understanding of interaction effect in ANOVA or regression. Let's keep things simple as the following. Suppose we have a standard 2 x 2 factorial design, where each factor ...
1
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0answers
57 views

testing interaction terms in regression model [duplicate]

Based on domain knowledge and preliminary variable selection, we have decided a set of 10 variables as predictor variables for building regression models. What are the general approaches to identify ...
0
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1answer
19 views

Can moderators be affected by the manipulated/independent variable?

I was wondering whether I can use a measured variable as a moderator in a linear regression. Say I have a manipulated variable X, and two measured variables Y and Z. There is a main effect of X on Y, ...
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0answers
12 views

Do I need to concern the direction change of main effects when including in the interaction term?

I am fitting a GLIMMIX model with two treatment (outcome variable is binomial variable), say x1 and x2, each of which is a dichotomous variable. When x1 and x2 only were included in the model, the ...
2
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1answer
53 views

Closed form for the variance of a sum of two estimates in logistic regression?

In logistic regression with an intercept term and with at least one dependent variable which is categorical, is there a closed form for the variance of the sum of the intercept and the coefficient of ...
2
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1answer
76 views

How to implement ordinal logistic regression for a factorial design

I have read a few answers (e.g. this, this and this) recommending to use the Ordinal Logistic Regression (OLR) as a generalized method when the Kruskal-Wallis is not suitable. For instance, a 2x2 ...
0
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1answer
23 views

How to deal with variable new behavior in multiple linear regression

Let's suppose that I have one model with 6 dummy variables for the days of the week and from those in 5 days a specific event happen, suppose that is daytostudy variable and I want to predict how many ...
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0answers
35 views

How to create dummy variables for interaction term between categorical variables?

I'm building a logistic regression model estimating the probability of hospitalization based on several predictor variables, including indicator variables for various diagnosis categories (coded as ...
0
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0answers
13 views

interpreting an interaction of two continuous variables in a mixed effects model [duplicate]

I am hoping for some guidance on how to interpret the interaction in a mixed effects model. The interaction is between two continuous variables (EarlyLanguageExposure and NeighborhoodSize). My ...
0
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1answer
33 views

Interaction Dummy

I have a model: $$ \ln({\rm earnings}) = 2.618656-0.0899657{\rm female}+0.382019{\rm white}-0.2754126{\rm female}\times{\rm white} $$ ${\rm female}$ and ${\rm white}$ are dummy variables. t= ...
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0answers
29 views

Dummy variable interpretation [duplicate]

I have a model: $$ \ln({\rm earnings}) = a+b_1{\rm female}+b_2{\rm white}+b_3{\rm female}\times{\rm white} $$ ${\rm female}$ and ${\rm white}$ are dummy variables. t= female=-1.65 white=8.86 ...
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1answer
70 views

Dummy variable interaction regression [duplicate]

I have a model: $$ \ln({\rm earnings}) = a+b_1{\rm female}+b_2{\rm white}+b_3{\rm female}\times{\rm white} $$ ${\rm female}$ and ${\rm white}$ are dummy variables. I have interpreted $b_1$ and $b_2$: ...
3
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1answer
86 views

Interpretation of interaction term

I have a model: $$ \ln({\rm earnings}) = a+b_1{\rm female}+b_2{\rm white}+b_3{\rm female}\times{\rm white} $$ ${\rm female}$ and ${\rm white}$ are dummy variables. I have interpreted $b_1$ and $b_2$: ...
0
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0answers
17 views

Cox proportional hazards (setting a reference level and an interaction with time)

I am currently trying to analysis some data in R using Cox proportional hazards. I have been able to get my coxph model to run but, I am having some coding difficulties. I have two factors (individual ...
0
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1answer
10 views

Citation for IV coefficient sign change with inclusion of interaction term

I have a two step regression model where I entered my three IVs in step 1 and one interaction in step 2. One of the IVs in the interaction has a positive coefficient in the first step and then a ...
2
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2answers
43 views

Interaction between a dummy variable and a variable with a quadratic form

I am finishing up an econometrics assignment and this problem has me stuck. I have estimated a regression equation for ln hourly wages on a gender dummy variable, several race dummy variables, a ...
3
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1answer
72 views

test interactions for multiple regression with many predictor variables

I have a data set with around 25 predictor variables. If I am planning to build multi-regression model against this data set. What are the general approaches to test the interactions of these ...
1
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1answer
72 views

Interpreting a linear mixed effect model's interaction term

I am a biologist and am attempting to analyze the effects of time and location on depth. I was told I needed to use a mixed effects model to account for the random variables of Individual and tracking ...
0
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0answers
10 views

Without interaction, an IV has a significant negative coefficient, but the coefficient became significant positive after interaction. Why?

Before interaction: IV1 sig neg IV2 sig pos After interaction: IV1 Sig pos IV2 Sig Pos IV1*IV2 Sig Neg Is that reasonable? How to explain the change of the sign from significantly negative to ...
1
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1answer
90 views

Specifying Cross-Level Interactions in LMER

I am trying to figure out if it's okay to specify cross-level interactions in a hierarchical model with fixed effect predictor variables at both levels using the ...
0
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0answers
41 views

Variance in significance with interaction term

I try to estimate the effects of NatRent (Natural resource rents in % of GDP) on GDP growth per capita (in %). When I include a Rule of Law (a measure for institutional quality) the coefficient of ...
1
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1answer
39 views

LSmeans - Unbalanced data with interactions

I wish to analyze an unbalanced data set with 3 variables Tleaf, Tair, and orientation (factor with two levels). Considering the effect of the factor "orientation", I wish to determine if "Tair" has a ...
1
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1answer
62 views

Interactions in Propensity Score Models

I am doing an analysis to see if a first-year seminar has an effect on student retention in college. Students choose whether or not to enroll in the seminar on their own, so it seems like it makes ...
2
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1answer
23 views

Which mean to use for centering variables when sample definition varies

I am centering variables that enter interaction terms in my linear regression. To check the robustness of my results, I exclude certain cases from the original sample, and re-run the regression ...
1
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0answers
20 views

Moderated regression with categorical predictors

I would like to do a moderated regression with SPSS. My problem is that the independent variable (predictor) is categorical, wheras the moderator as well as the dependent variable are interval ...
0
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0answers
25 views

Interpreting an interaction in the presence of main effects

I'm having a crisis of confidence in my stats and I was wondering if somebody could help me. I ran a 2 x 2 x 2 x 3 repeated measures ANOVA and got: 2 main effects 3 2 x 2 interactions and a 3 way ...
0
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0answers
17 views

mixed within-between ANOVA. I have a significant interaction but no significant main effect

I am currently trying to interpret the output of my mixed within-between ANOVA. I have 2 groups (experimental and control) and 2 time points (pre and post intervention).The dependent variable is a ...
1
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1answer
48 views

Using interaction terms in an MCMCglmm

I am using MCMCglmm models in R, with hierarchically nested data. The basic structure of the data is as follows - each dyad is a unique combination of focal/other: ...
2
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1answer
26 views

Explaining Non-Significant Moderations

Schools often teach us how to conduct and interpret Moderations. What they don't teach us is how to explain why a moderation didn't work out for statistical/methodological reasons. Assuming that the ...
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0answers
47 views

Sample size for a moderated hierarchical multiple regression analysis?

I am having a challenging time finding out the necessary sample size for a moderated hierarchical multiple regression analysis. The first five steps of the regression will include the 17 variables ...
0
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0answers
31 views

How to interpret 3 main effects when an interaction exists for only two of the variables?

I've been searching for interpretation guidance regarding the below problem, but all the resources I've seen have been fully crossed (i.e., all variables included in the interaction term). Below is a ...
1
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1answer
34 views

Metafor package: RMA and testing for interaction in two studies (Altman & Bland 2003)

I have traditionally used this simple test of interaction (http://www.bmj.com/content/326/7382/219) for comparing effect sizes between studies, and I would like to start performing it in R. Although I ...
0
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0answers
11 views

in a partial mediation relationship, can the independent variable and the mediator moderate each other?

Let's say age predicts experience, and experience predicts perceived reputation of doctor. Age also predicts perceived reputation directly, and moderates negatively the relationship between experience ...
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0answers
15 views

Is this a confounding interaction: using demographic data in a fractional factorial design?

I've created and run a choice experiment (conjoint analysis) using a fractional factorial design 3 x 3 x 3 x 3 (four factors with three levels each). I also collected some demographic data (age, ...
0
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1answer
68 views

Interaction terms and effect sizes in multiple regression

I know there are similar questions on here, but I can't quite find an answer that covers all of what I need. I am running multiple regression in r with two predictor variables and sometimes an ...
1
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0answers
18 views

how to interpret Interaction term in generalized linear model [duplicate]

I have an experimental condition (dummy-coded) as an categorical predictor, and one continuous predictor variable (treatment frequency). The dependent variable (Y) is consumer satisfaction This is ...
0
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0answers
26 views

Interactions between Dummy codded categorical variables in R

I have estimated a mixed-logit model in R.Here are my Results ...
1
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1answer
41 views

How should I interpret a factor that is significant both (1) in linear form in interaction with another factor and (2) in its quadratic form?

Our study aims to identify and understand how several ecological factors relate to parasite abundance in a colonial animal. However, we are uncertain on how to interpret a factor (density) that is ...
2
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1answer
59 views

Design of Experiments

Suppose a dermatologist wants to study the effectiveness of two different preparations of a skin lotion using two different forms of application, such as one versus two applications per day. She has ...