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

learn more… | top users | synonyms (1)

2
votes
1answer
20 views

Is it acceptable to not include high-order interactions (3-way and above) in the model when they are not by themselves of interest?

Is it acceptable to not include high-order interactions (3-way and above) in the model when they are not of interest and not part of the hypothesis that is being tested? NB. I am not talking about ...
0
votes
3answers
34 views

Covariate no longer significant after inclusion of interaction term

I'm trying to interpret some results here, and just want to make sure that my logic is sound. I'm predicting a binary outcome with a categorical predictor (gene level coded as 0, 1, or 2 dependant on ...
0
votes
1answer
26 views

Find the amount of variation due to another covariate

I'm trying to explain a binary outcome (cardiovascular disease) with a categorical predictor (gene level, coded as 0, 1, or 2 depending on the number of risk alleles present). I'm trying to determine ...
0
votes
0answers
6 views

Should I run Hierarchical regression to test moderation? Why?

I am an undergraduate student who currently preparing for my thesis paper. In my design, there is total 4 variable (1 predictor, 1 moderator and 1 outcome variable, all of them is in continuous ...
0
votes
0answers
36 views

Statistical Analysis help for thesis - Correlation, Probit, Tobit and Moderation

Hello CrossValidated users! I am writing here cause I need some guidance on my statistical analysis which has turned out far too complex for my basically begineer stats skills and my self research. ...
0
votes
0answers
23 views

Interpreting results from a mixed model with interactions

I need your help interpreting my model's results. To make story short, I have a continuous dependent variable $Y$, and two factors $A$ and $B$, each with $2$ levels $(A_1, A_2, B_1, B_2)$. My main ...
0
votes
0answers
14 views

Factorial design for interactions with ordinal DV

I want to make a 4 question, multiple choice survey in which each question asks about an analogous range of actions for slightly different scenarios. Each participant would only be administered the ...
0
votes
0answers
21 views

main effect and interaction effect

I faced difficulty with my data analysis output. I had two factors with split plot design. Separately, the main effect of the two factors on soil pH was significant. But their interaction effect was ...
2
votes
1answer
21 views

Metafor package: Interpreting rma model with two (or more) moderators.

New user of both stackexchange and R here. My questions are about mainly about interpretation, and my dataset is quite large, so I have not included my dataframe. I have two queries (in bold). Using ...
0
votes
1answer
39 views

How to run main effects and interactions in a stepwise regression?

I am using multiple regression with the backward elimination method. I have one control variable (social desirable responding) and four predictor variables (gender and three self-esteem constructs). ...
0
votes
0answers
41 views

How to perform multilevel interaction [closed]

Which model is correct and can be applied? $$Y=x_{1} + x_{2} + \left(x_{1}x_{2}2013\right)+ \varepsilon$$ $$Y=x_{1} + x_{2} + \left(x_{1}2013\right) + \left(x_{1}x_{2}2013\right)+ \varepsilon$$ ...
0
votes
2answers
21 views

Interaction between variables

I would like to regress basal metabolic rate (BMR) on height, weight, age and gender. How do I do this taking into consideration the interaction between the variable? Wouldn't I have to consider ...
1
vote
1answer
39 views

Can I compare two regression coefficients

I am comparing treatment outcome to two therapeutic treatments. Specifically, I am looking at how attachment moderates the relationship between therapeutic alliance and outcome. I hypothesize that the ...
0
votes
0answers
10 views

Interaction between percentage and population size in a regression

Assume I have a regression type model. Are their any statistical and/or substantial reasons NOT to include a two-way interaction which consist of a percentage and the corresponding population size. ...
0
votes
0answers
35 views

Interpreting / understanding intercept and slope values for an interaction using summary output in R

In R, using lme4, I am using a mixed model to test how a response (mode; continuous and normally distributed) is affected by a covariate (species richness (sr); continuous and normally distributed) ...
1
vote
1answer
32 views

Mixed model interaction (covariate+factor): How to interpret posthoc table output in R package phia?

In R, using package lme4, I have used the following 2 mixed models to determine I have a signifacnt interaction between a covariate (continous, normally distributed) and a factor (three levels: ...
0
votes
0answers
10 views

hierarchical logistic regression Block non-significant, interaction significant

I'm using hierarchical logistic regression and having some difficulty. Im trying to predict self-harm vs none based on IVs age, gender, alcohol, educational attainment. They are all yes/no except ...
0
votes
0answers
7 views

Correction for interaction model as it is significant in MR

I have used 1 DV and 5 IVs. I performed MR to test a model, entered age and gender in first block, IVs in second block, and interaction terms in third block. All the models are coming significant. How ...
-1
votes
1answer
29 views

How to confirm a two-way interaction in a three-way ANOVA model using SPSS

I have two groups of subjects, both undergoing two experimental conditions, and data are collected at two time points: pre- and post- condition. I run a 3-way ANOVA, with one between subject factor ...
0
votes
0answers
19 views

assess the interaction of two independent variables, on the dependent one

I have a set of laws/policies that overlap with each other through time (for example one started in 1990 and finished in 2001, and the other started in 1995 and finished in 1999). I want to examine ...
0
votes
1answer
25 views

Interaction model significant in multiple linear regression

This question is not about interaction effect, but about interaction model in Hierarchical Linear Regression. I have 1 DV and 5 IVs. I want to see which of the IVs is significant predictor of DV. ...
0
votes
0answers
15 views

Does it make sense to only drop a specific level of a categorical variable? [duplicate]

I don't have SAS and the dataset with me, so I made up this table (from my memory). Basically this is what I got: After deciding to leave the variable $age$ and $risk$ in my model, I created this ...
0
votes
1answer
35 views

Differenence between hierarchical linear regression and moderated multiple regression

What is the difference between hierarchical linear regression and moderated multiple regression? If I have one and two moderator variables and my models are: model 1- IV model 2- adding two ModVs ...
0
votes
0answers
14 views

ordered logistic regression with interactions

I am searching for the proper statistical method to test interactions between alternative-specific attributes of rank ordered responses (e.g., the age or gender of a ranked candidate) and individual ...
2
votes
1answer
73 views

Marginal effect calculation in Stata

My estimated dynamic GMM model results are as follows. $$Y = -0.009 + 0.009PF + 0.015PS - 0.001(PF\times PS)$$ I want to calculate the marginal effect of $PF$ at $PS$ (min, mean, max), which I can ...
0
votes
0answers
11 views

Oddly structured data - longitudinal data struggle - Interaction testing

I'm struggling with an analysis and I'd like to have your contribution. I work with neuroimaging, and I have tested the capacity of a certain imaging parameter (let's call it A) of predicting a ...
3
votes
1answer
35 views

Beginning anova in R: Phantom significance when testing for interaction terms

Suppose I create a dummy scenario as such: > A <- rnorm(10000) > B <- rnorm(10000) > C <- rnorm(10000) > Y <- A*B + rnorm(10000,sd=0.1) ...
1
vote
0answers
34 views

Interaction between continuous variable and categorical variable (2+ categories)

I'm about to do my analysis of my Master's thesis, but I have a question. I want to check whether media effects on political trust are different between natives and immigrants. These are my variables: ...
2
votes
2answers
51 views

What interactions to include in my GLM model?

I realize this might be a too general question, so I'll describe what I'm doing right now first. I'm working for a virtual insurance company and I have this dataset. It has severity (meaning ...
1
vote
1answer
27 views

A mixed ANOVA showed no significant interaction, but a dep. t-test showed a significant effect for only one of the groups

I have come across something that has got me kind of confused, I hope someone can help me out. I did a mixed ANOVA with one within subjects factor with two levels 'time' and one between subjects ...
0
votes
0answers
11 views

How do I conduct moderation using composite variables

I am running a few moderation analyses using a hierarchical multiple regression. All my variables are composites of parent and child versions of each scale. I created the composites by adding the ...
0
votes
1answer
39 views

Logistic Regression - Adding interactions makes Independent variable statistically insignificant

My name is Abhi & I am trying to better understand logistic regression by solving a few practice problem. I am using R and RStudio as the development environment Problem Statement Given the age, ...
0
votes
0answers
24 views

Multicollinearity

In a regression model with dummy variables, how does one check for intearction between the dummy variable and the independent variables?Wouldn't there be problem of multicollinearity when such ...
0
votes
1answer
14 views

Interpretation of two indexes Interaction Term

Respected Fellows. I will thankful if someone help me to explain my model results.my model is as follows. Yit=αPFit+βPSit+δ (PF*PS) it+εit Where Y is GDP per capita PF=Political Freedom Index ranges ...
2
votes
2answers
87 views

mediator or moderator variable?

I have been given a set of data and I am confused as to whether one of the variables is a moderator or mediator variable. The hypothesis is that stress and well-being have an inverse relationship. ...
0
votes
2answers
37 views

Interaction effect 2x2

I have a little question about a 2x2 design that keeps on confusing me. If I have this kind of 2x2 design where I can have these combinations in the conditions. No/No, Yes/No, No/Yes, Yes/Yes. The ...
1
vote
1answer
12 views

Help with determining model for cross-sectional data where all variables are dummies

I am currently working on my dissertation project where my data are essentially all dummies. From my dependent to my independent variables, everything is a dummy variable (0,1), at least for the ...
0
votes
0answers
8 views

Finding Significant Interactions for Linear Model with Experimentally Measured Interaction

Consider an experiment that has four groups, and all of them have experimental replicates. No treatment Treatment X Treatment Y Both X and Y When I fit an interaction model, and check the raw ...
0
votes
0answers
25 views

Interpretation and visualization of lmer output

I am trying to correctly interpret the output of my lmer-model and I also want to visualize an interaction contained in the model based on the intercept values. My variables and levels are Training ...
1
vote
0answers
53 views

Contradicting interaction significance with graphical visualisation in glmer

I'm investigating environmental effects (wind) on acoustic receiver detection probability for two types of transmitters using a binomial glmer. While my model analysis indicates that there's a ...
0
votes
0answers
13 views

Power estimates for an interaction in a 2X2 factorial design with a proportion outcome

I am trying to calculate the power that I will have to detect an interaction between 2 different interventions in a 2X2 factorial design. We aim to have about 850 participants in each of the four ...
0
votes
0answers
29 views

Interaction in a repeated measures logistic regression

I want to test for the effect of interaction between two variables using a repeated measures logistic regression but I don't know how. I am using Stata and the following lines: ...
0
votes
1answer
35 views

Stata ANOVA Interaction term differences

The following two statements produce different results. ...
0
votes
1answer
31 views

testing for mediation of interactions

I am somewhat familiar with various ways of testing mediation for factors in different types of regression analysis. (I'm using R and currently working with a multilevel binary logistic regression.) ...
0
votes
0answers
16 views

Follow up a significant interaction in ANOVA with dichotomous variables

Hopefully this is an easily answerable question, though I've been searching for an answer without any luck. I've run a 2x2x2x2 mixed-design ANOVA with two within-subjects and two between-subjects ...
1
vote
1answer
74 views

Doing post-hoc after a not significant interaction in mixed ANOVA

I conducted a mixed design ANOVA with two within-subjects factors: FactorA (2 levels), FactorB (2 levels), and one between-subjects factor: Group (2 levels). My main hypothesis regards the interaction ...
0
votes
0answers
19 views

Testing linear contrast in an unbalanced longitudinal design (R)

I'm experiencing some conceptual problems in testing a linear contrast in an unbalanced longitudinal design. I have performed some correlation analysis with brain imaging data. These analysis ...
1
vote
0answers
44 views

F-ratio in repeated-measures ANOVA

In factorial designs with one random factor and one fixed factor, the expected mean square for the fixed factor does contain three sources: the main effect, the interaction, and error Therefore, to ...
2
votes
1answer
52 views

How to prepare interactions of categorical variables in scikit-learn?

What is the best way to prepare interactions of categorical features before fitting with scikit-learn? With statsmodels I could conveniently say in R-style ...
0
votes
0answers
23 views

categorical variables in regression analysis and interaction terms

I am learning multiple regression with categorical variables and in a book I came across this problem. For yield of corn suppose there are two factors affecting, nitrogen level and depth of ...