T1-T2-R-R [Design Issues]

posted by d_labes  – Berlin, Germany, 2013-04-08 11:10 (4816 d 13:20 ago) – Posting: # 10367
Views: 7,800

Dear Ken,

❝ Sequence 1 R - T(cap) - T(tab) - R

❝ Sequence 2 T(cap)- R - R - T(tab)


To be period balanced (i.e. to be able to estimate period effects and get rid of them) each of your formulations have to occur at least once in each period.

IMHO your aimed design is a mixture of two partial replicate designs (T1RR and T2RR). According to ElMeastroso: Hokus-Pokus-Fidibus-Fidibus (combined).
So if you really have to use such a design derive the sequences starting from the sequences T1RR/RT1R/RRT1 and try to add T2 in a period balanced manner. F.i.
T1 R  R  T2
R  T1 T2 R
T2 R  T1
T2 R  T1 R

red: modifications to the TRR/RTR/RRT

❝ Are the statistics and computations same as that of fully replicate design?


I think: no :no:.
If you think in the direction of the FDA scaled ABE you have to evaluate two linearized ABE criterions (or a mixture?). That immediately rises the question of alpha adjustment.
If you think in EMA widened ABEL direction: May be you can calculate T1-R and T2-R from ANOVA of all data and s2wR from data on R only. But again the question of alpha adjustment arises.

Next question would be the regulatory acceptance. I would be very unsure about that. What do you think?

I myself would not go with such a design due to the uncertainties involved.

Regards,

Detlew

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