Tagged Questions

37 views

Term is significant linearly, quadratically and in interaction?

I used deletion tests to identify ecological factors that relate to the number of parasites on rodents. There is one factor that is significant linearly, quadratically and in interaction. However, the ...
63 views

How to address and acknowledge a significant interaction that has little practical meaning

I am building a model with a highly significant interaction. This interaction was one of our main hypotheses. It is clear, however, that the form that the interaction takes does not represent a ...
28 views

Regression when IV and DV are continuous

I have 2 groups with 30 subjects each who completed the MMPI-2. I have 4 continuous independent variables (IVs) (MMPI-2 validity scales) and one continuous dependent variable (DV) (MMPI-2 Scale 2). ...
100 views

When can we look at the significance of pairwise comparisons rather than an interaction term?

I will defend my Master's thesis on Thursday, and I have a doubt about an analysis that I have to present. In my experiment, I had two independent variables: Age category (SU = senior unemployed ...
52 views

Highly significant positive binary IV: Interaction always positive too

I'm working on a project where the main independent variable is binary. We then interact this variable with different continuous variables. The binary variable is by far the most significant variable ...
141 views

How to interpret the significant interaction of two non-significant main predictors?

I have two non-significant main binary variables in my binary logistic regression model, but their interaction is significant. The variables are centered and no multicollinearity is the case (all VIFs ...
31 views

Interpreting MLA results with interaction term [duplicate]

We are using multilevel logit regression (using R software). I have a bit of a debate with my colleague about how to interpret our results. In our first example, we are juggling the following ...
766 views

Two-way anova with interaction term: what is the point of a post-hoc test?

I have a statistics interpretation question. I've recently performed a two-way anova to identify an interaction term between my categorical independent variables (genotype + temperature) that ...
78 views

Test for whether a change is different in direction for subgroups?

I have a (large) population on which I randomly split into groups, and subjected one group to an experimental condition (call it change A) which demonstrated a significant improvement in a target ...
226 views

Unfold degrees of freedom of interaction in factorial design analysis in R

I've been trying to analyse data from a factorial design with missing cells without much success until now. I'm using Anova from car package, that, according with I've read, can handle unbalanced data ...
2k views

Joint model with interaction terms vs. separate regressions for a group comparison

After gathering valuable feedback from previous questions and discussions, I have came up with the following question: Suppose that the goal is to detect effect differences across two groups, male vs. ...
167 views

Group comparison: joint model vs. separate model, contradictory result

Any hint on this issue would be really welcome: The goal is to employ a two-country comparison analysis. When running two separate OLS regressions, one for each country, the coefficient of variable x ...
68 views

GWAS and Statistical theory - does the likelihood of a detectable main effect decrease with complexity?

I've been wondering recently about the difficulty of detecting statistically significant results from, say, genome-wide association studies. In these studies, many - ($10^{8}$) for example- ...
I fitted a Bayesian logistic regression in WinBugs and it has an interaction term. Something like this: \mathrm{Prob}(y_{i}=1) = \mathrm{logit}^{-1} (a + b_{1}*x_{i} + b_{2}*w_{i} + ...