Thus, in this design, we cannot estimate ABC, ABD, or CD separately from block differences. When a design is replicated in blocks but different effects are confounded in different replicates, we have partial confounding . This allows estimation of all effects, but with reduced precision for the confounded ones.
So ABC contrast = 14. This is the difference between Block 1 and Block 2? Let’s check block totals: design and analysis of experiments chapter 8 solutions
y = [25, 22, 20, 30, 24, 28, 32, 35]
:
| Block | (1) | a | b | ab | c | ac | bc | abc | |-------|-----|---|---|----|---|---|----|-----| | 1 | 25 | | | 30 | | 28 | 32 | | | 2 | | 22 | 20 | | 24 | | | 35 | Thus, in this design, we cannot estimate ABC,
C: -25-22-20-30+24+28+32+35 = (-47-20=-67; -67-30=-97; -97+24=-73; -73+28=-45; -45+32=-13; -13+35=22) ✅ So ABC contrast = 14