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Dear Ngene team,

I have done a D-efficient design using Ngene for my study using dummy var with zero priors and interaction as below:
;alts = alt1, alt2
;rows = 240
;eff = (mnl,d)
;block = 20
;model:
U(alt1)=
b1[0] * DUR[1,3,5,7,10](38-58,38-58,38-58,38-58,38-58) +
b2.dummy[0|0|0|0] * Prt[1,2,3,4,5] +
b3.dummy[0|0|0|0] * Accpt[1,2,3,4,5] +
b4.dummy[0|0|0|0] * Pain[1,2,3,4,5] +
b5.dummy[0|0|0|0] * Emthn[1,2,3,4,5] +
b6.dummy[0|0|0|0] * comm[1,2,3,4,5] +
b7.dummy[0|0|0|0] * slp[1,2,3,4,5] +

i1[0] * DUR * Prt.dummy[1] +
i2[0] * DUR * Prt.dummy[2] +
i3[0] * DUR * Prt.dummy[3] +
i4[0] * DUR * Prt.dummy[4] +
i5[0] * DUR * Accpt.dummy[1] +
i6[0] * DUR * Accpt.dummy[2] +
.
.
.
/
and I have done a pilot to measure the priors for the main design, I have some uncertainty about whether to put the the priors just the interaction part (in front of i's) or I need to put it with the dummy line as well (dummy[0|0|0|0] )?

Many thanks in advance,

Regards,
Mina

If you have priors available, you can put them both in the main effects (b1 to b7) as well as the interaction effects (i1 to i6).

Michiel

Thank you Michiel for your fast respond.