df peculiarities for 4x4 crossover and EMA [General Statistics]
Dear all,
for higher order designs with more than one treatment the EMA guideline recommends us to use only the data relevant for the comparison under consideration.
My (seems too) naive attempt for obtaining the degrees of freedom (df) of the corresponding ANOVA (without a further decomposition of the subject effect into sequence and subject nested within sequence) for a 4x4 crossover was:
Looks correct?
But on the output of my SAS dragon for a 4x4 study with 12 subjects and the sequences (Williams design, A=T1, B=T2, C=T3, D=R)
I see the following df for the pairs:
Any idea what's going on here?
for higher order designs with more than one treatment the EMA guideline recommends us to use only the data relevant for the comparison under consideration.
My (seems too) naive attempt for obtaining the degrees of freedom (df) of the corresponding ANOVA (without a further decomposition of the subject effect into sequence and subject nested within sequence) for a 4x4 crossover was:
source df
-------------
total 2N-1 (2*N values for a pair)
-------------
tmt 1 (2 treatments a pair)
period 3 (4 periods, no recoding)
subject N-1
-------------
MSerr N-4
Looks correct?
But on the output of my SAS dragon for a 4x4 study with 12 subjects and the sequences (Williams design, A=T1, B=T2, C=T3, D=R)
CDBA
DACB
BCAD
ABDC
I see the following df for the pairs:
A vs D
C vs D B vs D
tmt 1 1
period 3 2
Mserr 8 9
Any idea what's going on here?
—
Regards,
Detlew
Regards,
Detlew
Complete thread:
- df peculiarities for 4x4 crossover and EMAd_labes 2014-05-06 11:28 [General Statistics]
- df peculiarities for 4x4 crossover and EMA - follow-up d_labes 2014-05-07 11:43
- Mirror, mirror on the wall… Helmut 2014-05-07 16:49
- … Snow White or Little Red Riding Hood? d_labes 2014-05-08 09:18
- Mirror, mirror on the wall… Helmut 2014-05-07 16:49
- model matrix and lexer ElMaestro 2014-05-08 00:52
- model matrix and lexer d_labes 2014-05-08 08:38
- df peculiarities for 4x4 crossover and EMA - follow-up d_labes 2014-05-07 11:43