[R-lang] Re: anova formula repeated measures

[Scott Jackson]

Hi Mike :-)

Non-snarky suggestion: I think you are supposed to include the part of
the model that does not include the "within" factors again after the
Error term, so instead of:

by items (wrong): aov(response ~ within1 * within2 * between +
Error(item/between))
try: aov(response ~  (within1 * within2 * between) +
Error(item/between) + (within1 * within2))

and instead of : aov(response ~ within1 * within2 * between +
Error(subject/(within1*within2)))
try: aov(response ~ (within1 * within2 * between) +
Error(subject/(within1 * within2)) + (between))

Snarky suggestion:
lmer(response ~ within1 * within2 * between + (1|item) + (1|subject))
lmer(response ~ within1 * within2 * between + (1+between|item) +
(1+within1*within2|subject))
... etc.

:-)

I'm actually not 100% positive about the non-snarky suggestion, so let
me know if it works!
-scott

On Thu, May 20, 2010 at 8:33 PM, Michael T Hammond
<hammond@u.arizona.edu> wrote:
> all
>
> I am stuck on how to express a simple design for aov().
>
> It's an experiment with two within-subjects factors (phonological
> properties of my stimuli) and one between-subjects factor (presentation
> mode: some subjects get things visually, some auditorily). There are
> multiple subjects of course, and multiple items in each factor and
> intersection.
>
> If I left out the between-subjects factor, this is the normal way I would
> do this:
>
> by items: aov(response ~ within1 * within2 + Error(item))
>
> by subjects: aov(response ~ within1 * within2 + Error(subject/(within1 *
> within2)))
>
> When I add in the between-subjects factor, I can't get the error term
> right:
>
> by items: aov(response ~ within1 * within2 * between + Error(???))
>
> by subjects: aov(response ~ within1 * within2 * between + Error(???))
>
> I would have thought Error(item/between) and Error(subject/(within1 *
> within2)) respectively, but this does not work.
>
> I've been searching the web and have not found any examples of this sort
> of mixed design with aov().
>
> Does anybody have any ideas?
>
> Mike H.
>