Dear Doug,

I would like to be sure that I've understood the rules for the following contrast in a 2x2x2 design with diagnosis (D1, D2), gender (Male, Female) and handedness (Left, Right) as discrete factors.

D1MaleLeft
D1MaleRight
D1FemaleLeft
D1FemaleRight
D2MaleLeft
D2MaleRight
D2FemaleLeft
D2FemaleRight

interaction between Diagnosis, Gender, and handedness
 [ 1    -1    -1     1    -1     1     1    -1]

interaction between Gender and handedness for D1
[ 1    -1    -1     1     0     0     0     0]/2

interaction between Gender and handedness for D2
[ 0     0     0     0    -1     1     1    -1]/2

interaction between Diagnosis and handedness for Males
[ 1    -1    0     0    -1     1     0    0]/2

interaction between Diagnosis and handedness for Females
[ 0    0     1    -1    0     0     -1    1]/2

interaction between Diagnosis and Gender for Left
[ 1    0    -1    0    -1     0     1    0]/2

interaction between Diagnosis and Gender for Right
[ 0    1     0    -1    0    -1     0    1]/2

Many thanks in advance.

Gabriel