I ran a three-way ANOVA to find effect of insecticide (2 levels), species (2 levels) and location (2 levels) on body condition of turtles. I did not find any three-way interaction. However, I found an interaction between insecticide and species! I am not familiar with three-way ANOVA and I dont know how should I interpret my results and plot my data!! should I run a two-way ANOVA and focus on main effects?
1 Answer
You should be able to work with the model as is. Plot your data! What does it say? What about post-hoc tests? Keep going!
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$\begingroup$ So, you are saying I should run a Two-way? sorry I did not get it $\endgroup$– NonMar 3, 2017 at 19:48
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$\begingroup$ Probably running a three way with that one significant two-way interaction would work. One could wonder whether some simple transformation of the response variable would eliminate the interaction, but we can't say much about that without the actual data. $\endgroup$ Mar 3, 2017 at 22:25
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$\begingroup$ Ok, so should I report two-way interaction between insecticide and species. and also report F value for each factor from the same table? or run two-way ANOVA and conclude on that? $\endgroup$– NonMar 4, 2017 at 2:23
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$\begingroup$ @MichaelHardy Ok, so should I report two-way interaction between insecticide and species. and also report F value for each factor from the same table? or run two-way ANOVA and conclude on that? $\endgroup$– NonMar 4, 2017 at 3:05
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1$\begingroup$ I agree with @jebyrnes - plot your data, use the entire 3-way ANOVA table and post-hoc tests. A picture paints a thousand words so plot your data! You might be able to get more useful answers by posting the ANOVA table in your question, as well as any graphs you have. $\endgroup$ Mar 4, 2017 at 20:08