Tagged Questions
1
vote
0answers
33 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 ...
1
vote
0answers
19 views
How to Partition An Interaction SS in ANOVA
I'm a new user of R and I'm trying to replicate Table 6.18 on page 262 in Statistical Procedures in Agricultural Research, By K. A. Gomez and A. A. Gomez. New York, Chichester, etc.: Wiley (1984). ...
1
vote
1answer
58 views
2x3 ANOVA interaction no longer significant after including a covariate?
My experiment had a 2x3 design with one covariate. If I analyse the results using an ANOVA, I get a strongly significant interaction between the two main factors (p<.001). If I add the covariate ...
1
vote
1answer
54 views
How do I report a 4x4 ANOVA interaction
How do I report this 4x4 interaction (this is part of a 4x4x2 ANOVA)? This is an interaction between the factors grouping (Gestalt heuristics for visual grouping of compound figures) and set size ...
1
vote
0answers
23 views
Quantify mediation effect of one variable on interaction of 3 others
I would like some quantitative measure of the degree to which an observed categorical variable predicts mediates the effect of an experimentally controlled factor on a continuous DV. The situation is ...
0
votes
1answer
51 views
2
votes
3answers
279 views
Reporting interaction effect for a 2x3 ANOVA
I have used a 2x3 mixed between-within subjects ANOVA to assess the impact of three feedback conditions (Grade, Comment and No Feedback) on participants’ scores on the Specific-Self Efficacy Scale on ...
0
votes
1answer
115 views
Two-way ANOVA repeated measures
I would like to know, if you got a significant interaction in a two-way repeated measures ANOVA in SPSS, how can you visualize the interaction (especially using syntax)?
2
votes
1answer
173 views
How to interpret overlapping interaction plots?
I have an interaction plot that seems to be overlapping on top of one another, what does this signify?
1
vote
1answer
51 views
ANOVA 'factor level comparison' methods
We had an exercise in statistics class where we did a small ANOVA analysis. We were comparing how the two levels of a factor influenced the response under different conditions (combinations of other ...
3
votes
1answer
246 views
Analyse unbalanced repeated measures 2x2x2x2 type II anova interactions
I have a run an unbalanced 2x2x2x2 Type II ANOVA in R and am having trouble following up on the results. Here is the output:
...
1
vote
0answers
43 views
How to describe a study design looking at one sample of which different data was collected during several periods of time
I am conducting a research on the effect of burnout on anxiety, tiredness and sleep, before a particular event and after an event.
There is one sample of which different data was collected over 6 ...
0
votes
1answer
46 views
Testing Independent variables impact during different decades
I am trying to test the impact that independent variables, Growth, Inflation, and Z (good economy for several quarters), have on the presidential vote received by the incumbent party.
My alternative ...
1
vote
0answers
130 views
Difference between p values of interaction
I was wondering which p-value to use when i am testing the significance of an interaction between two continuous variables.
Here is my model with the interaction:
Coefficients:
...
1
vote
2answers
272 views
Do I discuss the lack of interaction if I already discussed lack of main effects?
I conducted an experiment with 2 independent group variables (gender and language - language indicates either native speakers or 2nd language speakers) and ran a 2 way ANOVA. There were no main ...
3
votes
0answers
178 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 ...
-1
votes
1answer
94 views
How can I change the scores to make interaction effect in two way ANOVA significant?
My question is how to make an interaction effect become significant in two-way ANOVA.
If my main effect A has an F value of F(1,80)=25.5 for example, and my main effect B has an F value of ...
0
votes
0answers
89 views
3 x 2 Design using ANOVA - questions about significant interaction
I'm doing a 3 (12, 14, 16 year olds) x 2 (male, female) design investigating moral development in children/adolescents. I have decided to use a 2-way ANOVA after rejigging my design and deciding to ...
1
vote
2answers
695 views
Repeated measures ANOVA within and between factors
I have conducted repeated measures ANOVA, with 2 factors: One within factor (time, pre-post intervention) and one between factor (...
6
votes
2answers
548 views
How to interpret lower order interaction when higher order interaction is significant?
I have a question about the interpretation of lower order interaction terms in the presence of a significant higher order interaction effect.
Suppose I have a 2 (factor $A$) $\times$ 2 (factor $B$) ...
2
votes
0answers
138 views
How to test and examine interaction effect in 2 by 3 by 6 mixed ANOVA design?
Background:
I have two groups of children - one group with normal hearing and one with permanent hearing losses - call them NH and PHL.
Each child has had a hearing test, consisting of 6 different ...
5
votes
2answers
2k views
What is a valid post-hoc analysis for a three-way repeated measures ANOVA?
I've performed a three-way repeated measures ANOVA; what post-hoc analyses are valid?
This is a fully balanced design (2x2x2) with one of the factors having a within-subjects repeated measure. I'm ...
0
votes
0answers
401 views
Three-way Repeated Measures ANOVA [closed]
I've posted this question (along with example code and output) at http://www.reddit.com/r/rstats/comments/tglt8/threeway_repeated_measures_anova/
Is this a valid ANOVA model, and are sphericity tests ...
1
vote
1answer
420 views
How to interpret 3-way interaction with one continuous variable in mixed model
I have problems interpreting the direction of the effects in my model. Can you help me with this?
I conducted an experiment which includes
between subject factor:
group=2 (coded as 0-1)
within ...
1
vote
0answers
109 views
Interaction terms and BUGS
It occurred to me that how one writes an interaction term in BUGS depends on the types of predictors that are "interacting". Suppose data that are long (rather than wide). Then, a model with an ...
8
votes
2answers
2k views
Regression vs. ANOVA discrepancy
I was always under the impression that regression is just a more general form of ANOVA and that the results would be identical. Recently, however, I have run both a regression and an ANOVA on the same ...
3
votes
2answers
463 views
Best method to visualize large interaction between two factors
In a simple experiment I asked participants to make acceptability judgements (9-point Likert scale) when they observed different animated virtual characters. I have two factors: character (7 levels) ...
1
vote
1answer
295 views
Two-way ANOVA main effect and interaction query
I have a MINITAB printout I was hoping someone could help me with. My question is- from the table below how do I distinguish between a main effect and an interaction?
Study: Three drug treatments ...
1
vote
3answers
2k views
Reporting main effects and interaction from ANOVA
When reporting a two way 2 x 3 mixed ANOVA I have recently heard that the interaction effect should only be reported if the two main effects are significant (APA style). Is this correct?
1
vote
0answers
257 views
Contrast to ANOVA with interaction term
I need to fit orthogonal contrasts to the following model. The following example data.
...
2
votes
1answer
780 views
Error bars in interaction plot for ANOVA
I notice whenever I see an interaction plot for say a simple two factor ANOVA there are no error bars present, just the points for the estimated means. Is it ever appropriate to display error bars in ...
3
votes
5answers
501 views
Is it appropriate to examine an interaction effect that is almost statistically significant?
I am conducting a 2x2 within-subjects design. When I plot my results it appears that there will be an interaction between my variables but unfortunately none is emerging p=0.08. I find it a shame that ...
4
votes
1answer
327 views
Representing the anova's interaction in R
I read in the book The basics of S and S-plus that "A:B" functions as "Interaction between A and B".
However, in other book I read "There is never an interaction effect for two factors when one is ...
4
votes
3answers
244 views
Counterexample for interaction and parallel curves?
It is said that if the plots of the hypothetical responses are not parallel, but crossed, there is interaction. Suppose we have two factors. Is it possible that the plots cross but we do not have ...
5
votes
1answer
2k views
Which non-parametric test can I use to identify significant interactions of independent variables?
I have an experiment producing results (dependent variables) that don't pass tests of normality, thus I am testing hypotheses using non-parametric tests.
My DVs are continuous, while my factors ...
