The support of an association rule is the percentage
of groups that contain all of the items listed in that association
rule. The percentage value is calculated from among all the groups
that were considered. This percentage value shows how often the joined rule
body and rule head occur among all of the groups that were considered.
Thus, the support of a rule is the percentage equivalent of
a/b,
where the values are:
- a
- The number of groups containing all the items that appear in the
rule
- b
- The total number of all the groups that are considered
You can specify that only rules that achieve a certain minimum
level of support are included in your mining model. This ensures a
highly meaningful result. It is also one of the ways in which you
can control the number of rules that are created.
You set the minimum support when defining mining settings.