Populations Factor 2 Level 1 Level 2 Level Pooled Factor 1 Level 1 P11 P12 P1J P1• Level 2 P21 P22 P2J P2• Level I PI1 PI2 PIJ PI• Pooled P•1 P•2 P•J   Note: Pij has mean µij and variance where for each i. where for each j.

Table 4: Random variables to represent values in each combination of levels in a two-factor experiment.