Bioequivalence and Bioavailability Forum

Dear all!

Some more information: Using 3 treatements, a Williams design can be used leading to 6 sequences with 3 periods

Sequence 1: A, B, C
Sequence 2: A, C, B
Sequence 3: B, A, C
Sequence 4: B, C, A
Sequence 5: C, A, B
Sequence 6: C, B, A

we are also planning to perform replicates and the question is: how should the order of replicates be specified?

1) Replicated Williams design: the order of treatments are identical for first and second part:

Sequence 1: A, B, C ; A, B, C
Sequence 2: A, C, B ; A, C, B
Sequence 3: B, A, C ; B, A, C
Sequence 4: B, C, A ; B, C, A
Sequence 5: C, A, B ; C, A, B
Sequence 6: C, B, A ; C, B, A

2) Replicated Williams design where the order of treatments in the second part is determined randomly, for example:

Sequence 1: A, B, C ; B, C, A
Sequence 2: A, C, B ; C, A, B
Sequence 3: B, A, C ; A, B, C
Sequence 4: B, C, A ; A, C, B
Sequence 5: C, A, B ; B, A, C
Sequence 6: C, B, A ; C, B, A

I would be happy to receive some comments regarding the pros and cons for these two designs

best regards

Martin