Conclusions from the effects plot

We can make the following conclusions from the effects plot.
 A ranked list of main effects and interaction terms is:
X2
X7
X1*X3 (confounded with X2*X7
and X4*X6)
X1
X3
X2*X3 (confounded with X4*X5
and X1*X7)
X1*X2 (confounded with X3*X7
and X5*X6)
X3*X4 (confounded with X1*X6
and X2*X5)
X1*X4 (confounded with X3*X6
and X5*X7)
X6
X5
X1*X2*X4 (confounded with other
3factor interactions)
X4
X2*X4 (confounded with X3*X5
and X6*X7)
X1*X5 (confounded with X2*X6
and X4*X7)
 From the graph, there is a clear dividing line between the
first seven effects (all effect > 50) and the last eight
effects (all effect < 20). This suggests we retain the
first seven terms as "important" and discard the remaining
as "unimportant".
 Again, the confounding structure on the right reminds us that,
for example, the nominal effect size of 70.0125 for
X1*X3 (molarity*pH) can come from an
X1*X3 interaction, an X2*X7
(solute*clamping) interaction, an X4*X6
(gas*horn depth) interaction, or any mixture of the three
interactions.
