[R-lang] Re: anova formula repeated measures

[Adrian Staub]

Hi All - A generally useful document for within, between, and mixed 
ANOVA designs, in R, is the following, from Roger Ratcliff's lab:

http://star.psy.ohio-state.edu/coglab/Demos/r.anova.html

Best,

Adrian

On 5/21/2010 1:55 AM, Ingo Plag wrote:
> Dear Michael,
>
> the best way to do this might be using mixed effects regression.
> This circumvents your problem and at the same time is a statistical 
> technique that is superior to by-items and by-subjects anovas.
>
> In case you are not familiar with it, Baayen's book (2008, Analyszing 
> Linguistic Data, CUP) gives a nice introduction in one of the last 
> chapters.
>
> With best wishes,
> Ingo Plag
>
>> 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.
>>
>

-- 
Adrian Staub, PhD
Assistant Professor
Department of Psychology
University of Massachusetts Amherst
430 Tobin Hall
Amherst, MA 01003

astaub@psych.umass.edu
http://www.people.umass.edu/astaub/
413-545-5925