Useful rules for resolution IV or V designs are: (i) In any resolution IV design, the main effects are clear. (ii) In any resolution V design, the main effects are strongly clear and the two-factor...

Useful rules for resolution IV or V designs are:

(i) In any resolution IV design, the main effects are clear.

(ii) In any resolution V design, the main effects are strongly clear and the

two-factor interactions are clear.

(iii) Among the resolution IV designs with given k and p, those with the largest

number of clear two-factor interactions are the best.