Questions tagged [interaction]
A situation where the effect of an explanatory variable may depend on the value of another explanatory variable.
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Software that finds correlations between loosely dependent time-series?
I'm not sure if this is the right kind of question for this site, so please let me know :)
I'm looking for a time series data analysis platform, so I can take a collection of time series at 15-...
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23 views
How do I interpret a significant three-way interaction when all two-way interactions are not significant? [duplicate]
How do I interpret a three-way interaction when all two-way interactions are not significant?
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1answer
33 views
Calculate interaction effect confidence intervals in zero-inflated poisson regression
I'm conducting a zero-inflated Poisson regression using the pscl package in R. I've included interaction terms but am having an issue with interpretation. I am assuming an additive effect and summing ...
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1answer
55 views
multiple logistic regressions with binary predictors vs single logistic regression with categorical predictors
I would like to know which is statistically more advisable and what are the advantages and disadvantages of each approach.
My data frame data has ...
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0answers
26 views
Independent variables and moderator variables correlate (three-way interaction)
let's assume I hypothesize:
H1: A direct effect of X1 on Y
H2: A direct effect of X2 on Y
H3: A two-way interaction between X1 and X2
H4: A three-way interaction between X1, X2 and X3
H5: A three-...
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1answer
25 views
Effect Modification, Confounding, and Correlation
I am trying to estimate the effect of a policy intervention (X) on patient outcome(Y) from an administrative data. In the data set, around 20% of the patients have received the intervention. Even ...
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1answer
20 views
How to interpret positive interaction term with negative individual variable effects? [closed]
Hi I have interaction term which is significantly positive while individual variable effects are both negative. Moreover the individual coefficients magnitude and significance increases after adding ...
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1answer
27 views
interaction with a mixed logistic regression using mlogit on choice data
What is the best way to analyse interactions in choice data between an individual specific variable and an alternative specific variable?
I have designed a discrete choice experiment in which ...
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44 views
Interpretation of interaction terms
I try to improve my statistical knowledge and right now I am working on a regression that contains interaction terms. I am currently investigating the effects of different variables ($a_1$, $a_2$ etc.)...
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0answers
9 views
Simple effects analysis - correct univariate results for multiple comparisons?
I tested the effect of two factors with both each three levels on a DV. When analyzing my data, the ANOVA revealed two significant main effects and a significant 3x3 interaction which I now plan to ...
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11 views
Obtaining the fitted values of main effects and interactions when GLM coding is used
In short, I need to decompose the fitted values obtained from ANOVA into components corresponding to each term in ANOVA statement. This problem appears trivial, but it becomes tricky when GLM coding ...
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0answers
9 views
Comparing two difference-in-difference models when making the treatment group larger
I have a question regarding some potentially existing empirical tests in the difference-in-difference context.
Assume that I have the usual setting of observing some hypothetical outcome for a ...
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0answers
22 views
Method for testing interaction in regression analysis
I am running a linear model with 6 explanatory variables (5 in classes, 1 quantitative), and would like to test which interaction(s) are eventually significant.
I think an ascendant stepwise method ...
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0answers
12 views
testing specific effects from a significant interaction in mixed models
Let's say I have this model
...
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6 views
regression analysis assessing the relationship between brain volume and behavioural score, main effect but what to do with the moderating variable?
I am conducting a regression analysis to look at the relationship between a behavioural score and brain volume. My sample is made of 2 patient groups: A and B. The model includes the following ...
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1answer
40 views
What would be the appropriate statistical test for my study?
What would be the appropriate test for a study that has:
2 categorical independent variables with 2 levels each,
1 moderator variable (and would it matter if my moderator is categorical or continuous?...
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0answers
36 views
Causal model: Controlling for moderating effect of confounder (rather than the confounder itself)
My linear regression model can be described by the following causal graph:
I want to explain the sign of the causal effect of $X$ on $Y$, but unfortunately cannot measure $Z$ directly. Thus, I can ...
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1answer
43 views
Feature Interaction Strength in Catboost
I was wondering if anyone knew how the feature interaction strength is calculated in the catboost package. The documentation https://catboost.ai/docs/concepts/output-data_feature-analysis_feature-...
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Can I test for different moderation effects using several regression models or do they have to be included in one?
Let's say I have 8 independent variables A-H which I want to test for significance regarding each of their influences on the dependent variable Z. Now let's say that I additionally suspect moderation ...
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Does anyone have a reference for the assumptions of moderated hierarchical regression?
I am writing up the results of a moderated regression and need a reference for the relevant statistical assumptions. However, I am having trouble finding one.
Would anyone have a reference to share?
...
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11 views
Interpreting the moderator influence from the two-way slope graphs
I am testing the moderation influence of Structural Assurance(SA) on the positive relationship between social influence(SI) which is an independent variable, and the continuance intention(CI) which is ...
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1answer
38 views
Slope is negative but confidence limits contain zero, how do I describe the effect?
I performed an ANCOVA on final height (height4) with initial height as a covariate.
Dependent variables:
ipc.gm = initial % cover of garlic mustard
fence = factor with 2 levels: Fence, Open
There ...
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0answers
15 views
Appropriate follow-up test in a 2-way within groups ANOVA
I have a 2 (time1 vs time2) x 2 (drug blood concentration: resting vs. post-exercise) within subjects design. I want to know if the difference between post-exercise and baseline is different at each ...
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Is this the correct way to interpret odds ratio for three way interaction?
grateful for any thoughts about this.
I'm doing a generalized linear model analysis of a binomial dependent variable (whether the participant gets the correct answer or not).
I have three ...
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0answers
23 views
ANCOVA significant interactions in R: How do I interpret slopes from interaction plots?
I've got a continuous dependent variable height4, a continuous covariate height, a continuous dependent variable ipc.gm, and a factor fence with 2 levels: Fence and Open.
I've got a significant ...
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0answers
9 views
Significant interaction in Mixed-design 2-way ANOVA. How to correct for multiple comparisons?
I have conducted a mixed-design two-way ANOVA (between subjects variable : 2 levels; within subjects variable : 8 levels). I have a significant main effect of between and within subject variables and ...
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How to compare growth rates estimated from GLMM?
I've counted aphid populations under 5 different treatments for about 10 weeks. There were 4 replicates of every treatment. I'm interested in comparing the first 4-5 weeks, where the populations ...
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34 views
Interpreting OLS regression with continuous interaction?
I'm a beginner when it comes to statistics and I have a question about how to interpret the results of this OLS model and specifically the interaction of two continuous variables.
The following ...
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1answer
36 views
Interpreting categorical interaction terms
I am wondering how to interpret results of interaction terms (see image below).
I think to know that the interaction term 1 (IV x potential moderator group 1) depicts the difference of association ...
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1answer
33 views
Testing two potential interaction variables (or potential sources of effect heterogeneity) against each other
I have an experiment I have run, and I am testing for heterogeneous treatment effects (pre-registered and not fishing for any particular result!). Let's call the outcome $Y$ and the treatment variable ...
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0answers
14 views
Analyse interaction/moderators first and then adjust for confounding
In my research I am interested in subgroup analyses.
I am looking at a general association between two variables (environment and health outcome) with interaction terms (personal factors, which are ...
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0answers
19 views
How to interpret a two-way interaction in a 3-way interaction model
I am trying to predict y with variables a, b and c. I have two models and I get different results depending on how I fit my model.
Model A is the simpler model, in which I exclude variable c. In ...
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3answers
74 views
Multiple regression with dummy variables and interaction term
We have done a multiple regression analysis to see how gender and experience affect salary. We used a dummy variable for gender and then we also added the interaction variable (female work experience)....
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0answers
18 views
Interpreting interaction effect between two categorical predictors using linear mixed model
I have read other threads regarding this topic, however, I haven't come across a results table that looks similar to mine (below) so I am seeking some clarification. I am using MIXED (SPSS v25) to ...
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Comparing Logistic regression Pseudo-$R^2$ between model with Interaction effects and model without Interaction effects
I have two Logistic regression models, one including manually selected (hierarchical) interaction effects between few independent variables and one model without any interaction effects. Both models ...
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Are conditional effects the same as main effects when using orthogonal contrast codes for categorical predictors?
I ran into a presentation discussing the difference between conditional (or simple) effects and main effects when interpreting regression output in the presence of interaction terms.
http://www.lrdc....
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Three-factor ANOVA
I’m analysing a dataset on contents of flavonoids in different parts of a plant (factor A: leaves, flowers, stems), during different phases of plant growth (factor B: vegetation, full flowering, ...
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Assess impact on results of participants recruited via additional outreach efforts
I am currently working on a project that evaluates certain study recruitment strategies in regards of increasing participation among different subgroups.
One of those strategies is reminder letters. ...
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0answers
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What is the best way to choose interactions between continuous variables for Logistic Regression?
I have a logistic regression model that I am working on for a school project. I have about 55 predictors, all of which are continuous. I am relatively new to the idea of "interactions" between ...
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Linear regression Interaction Quadratic terms
In linear regression, if I have dependent variable Y and independent variables A and B, where B has a quadratic relationship with Y, and I'm looking for a possible interaction between A and B, I would ...
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What information can be extracted from plotting two variables of a multiple logistic regression against the prediction?
I have a multiple logistic regression model that has the form of:
disease ~ treatment + x2 + x3 + x4 + x5
Where disease can take values 1 and 0 (diseased or not ...
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1answer
12 views
Significance of the sum of the main effect and interaction term
Consider a simple linear regression with an interaction term:
$Y=b_0 + b_1X +b_2Z+b_3XZ$
where $X$ is continuous and $Z$ is a dummy.
I want to find out whether $X$ has a significant impact on $Y$ ...
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0answers
7 views
Main effect changes after adding interaction term [duplicate]
I have two models:
Model 1:
Y = b0 + b1X1 + b2X2 + b3X3
Model 2:
Y = b0 + b1X1 + b2X2 + b3X3 + b4X2X3
all coefficients are significant in both models but b2 changes from positive in "model 1" ...
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1answer
36 views
multicollinarity issue
I ran a logistic regression moderation analyses and I noticed that with the addition of the interaction term, one of the predictors flipped signs. The variable (X) was previously -.015 and became .006 ...
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1answer
20 views
Is it possible to include an interaction term in logistic model if the interaction term had no observation in some category?
I tried to do a binary logistic regression.
y was a binary outcome
x1 was an independent variable by 5 categories
x2 was an independent variable by 2 categories
I found that x1 and x2 had the ...
8
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1answer
107 views
Does correlation between variables in an interaction matter?
Suppose you fit a model $y = x_1 + x_2 + x_1\times x_2$. Are there any practical implications for estimation of the interaction effect if $x_1$ and $x_2$ are correlated?
I understand there could be ...
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1answer
56 views
Interpreting interaction with quadratic term
$Y$ (scores among black students) $\sim X_1 + X_1^2 + X_2 + (X_1 * X_2) + (X_1^2 * X_2)$
...
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1answer
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Different regression coefficients from statsmodels OLS API and formula ols API
I work at a relatively large Swedish retail company where I am currently performing initial linear regression in order to understand the linkage between dependent variable store sales (number of ...
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Interpretation of two dummy variables in interaction with addition of new variables
I have a mixed effects model with an interaction between two dummy variables. Y variable is continuous. My questions:
Does the interpretation of the variables included in the interaction (and the ...
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0answers
19 views
Finding Null distribution for gbm interactions
I am trying to determine which interactions in a gbm model are significant using the method described in Friedman and Popescu 2008. My gbm is a classification model with 9 different classes.
I'm ...
