0
$\begingroup$

I have experiment leading to 4-way ANOVA:

  • 3 experimental groups.
  • participants in each group responded to 70 trials.
  • Reaction time as DV.
  • trials were divided into separate groups by full factorial design by three variables A,B and C.

I'm not sure what is the best way to analyze the data. I can run one 4-way ANOVA with (RT ~ group*A*B*C) or run three 3-way ANOVAs for each group separately (RT ~ A*B*C).

What is the best practice? Run one 4-way ANOVA, but harder to interpret, or run three 3-way ANOVAs and correct for multiple testing?

Improve this question
$\endgroup$
2
  • $\begingroup$ Please consider: if each variable, A, B, and C, had just 2 levels, then there would be 2x2x2=8 groups. Does this design really have only 3? And if so, what splits the participants into these 3? I suspect that where you speak of "variables" you actually have 3 levels of a single variable. $\endgroup$
    – rolando2
    Commented Jan 4, 2016 at 23:47
  • $\begingroup$ Sorry for the confusion. Group is also a variable (with 3 levels), variables A,B and C have 2,2 and 3 levels respectively. $\endgroup$
    – fidadoma
    Commented Jan 7, 2016 at 15:10

1 Answer 1

Reset to default
0
$\begingroup$

If you are not really interested in the comparison between groups go for the 3-way definitely. The 4-way case will end up with A LOT of interactions for you to study. This is very complex and tiring...

Improve this answer
$\endgroup$
2
  • $\begingroup$ Thank you, unfornutaly, I'm interested in comparison between groups. Can I run three 3-way anovas and correct for type I error? I'm not sure, how to interpret significant coeficients for higher level interactions. $\endgroup$
    – fidadoma
    Commented Jan 7, 2016 at 15:14
  • $\begingroup$ So one analysis for each group is not an option. You could remove one of the factors or run the analysis with all 4 of them, selecting what interactions and main effects you think are important to be interpreted. $\endgroup$
    – Walter
    Commented Jan 8, 2016 at 0:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.