R help - Jan 2011 - Choosing statistical test - Fisher's Exact Test?

Hi I was wondering whether anyone can help me with this problem....it's been
driving me nuts, I've been trying to figure it out for months and months
without success!! Basically I have a group of participants who attended 2
experimental sessions a few months apart. I took measures of the way they
approach two tasks at Time 1 and the same two tasks at Time 2. I have
categorical data (a frequency table for each task) consisting of the goal
profiles that participants adopted at Time 1 and at Time 2. I would like to
test whether there is a significant difference between the goal profiles
that participants adopted at Time 1 and Time 2. Is Fisher's exact test the
test to use in this case? 

I would really really appreciate any help!!

Thanks


Debbie
-- 
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It appears that you have a 2x2 table coming from paired binary data..

If this is the case the McNemar test is appropriate.
See
?mcnemar.test

or even better the package exact2x2, function mcnemar.exact() for an 
"exact" approach,

vito




Il 18/01/2011 14.40, debz ha scritto:
>
> Hi I was wondering whether anyone can help me with this problem....it's
been
> driving me nuts, I've been trying to figure it out for months and
months
> without success!! Basically I have a group of participants who attended 2
> experimental sessions a few months apart. I took measures of the way they
> approach two tasks at Time 1 and the same two tasks at Time 2. I have
> categorical data (a frequency table for each task) consisting of the goal
> profiles that participants adopted at Time 1 and at Time 2. I would like to
> test whether there is a significant difference between the goal profiles
> that participants adopted at Time 1 and Time 2. Is Fisher's exact test
the
> test to use in this case?
>
> I would really really appreciate any help!!
>
> Thanks
>
>
> Debbie
-- 
===================================Vito M.R. Muggeo
Dip.to Sc Statist e Matem `Vianelli'
Universit? di Palermo
viale delle Scienze, edificio 13
90128 Palermo - ITALY
tel: 091 23895240
fax: 091 485726/485612
http://dssm.unipa.it/vmuggeo