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:

Block 1: (1)=25, ab=30, ac=28, bc=32 Block 2: a=22, b=20, c=24, abc=35

A: -25+22-20+30-24+28-32+35 = (-25+22=-3; -3-20=-23; -23+30=7; 7-24=-17; -17+28=11; 11-32=-21; -21+35=14) ✅

: Estimate main effects and interactions, accounting for blocking.