LLN, le 24/06/05
Michael,
>The experiment is organised in six sessions, e.g,
>
>R A; R B; R A; R B; R A; R B. (randomized across subjects)
>
>I appreciate that it would have been better to have all conditions
>in each session,
>but this would not allow us to properly address our specific aims.
>
>I don't think we can contrast the main effects of interest at the
>first level, so
>to examine the A v B conditions, would it be better to do this at
>the second level, i.e.,
>using the A v R and B v R contrasts?
For the reason you mentionned (A and B in different sessions), A v B
is not appropriate given your design, but
(A-R)-(B-R)
should do what you want, even at the first level.
Hope this helps,
Mauro.
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Mauro PESENTI
Research Associate, National Fund for Scientific Research (Belgium)
Unite de Neurosciences Cognitives
Departement de Psychologie
Universite Catholique de Louvain
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