36
Selecting Relation Patterns
From the list of relation patterns found, we are interested in the most effective ones.
Precision is not the only criterion for effectiveness. For example, the retrieved pat-
tern
f¨odd 30 mars 1853 i proved to a 100% precise pattern expressing the relation
between a person (
Vincent van Gogh) and his place of birth (Zundert). Clearly,
this rare phrase is unsuited to mine instance-pairs of this relation in general. On
the other hand, high frequency of some pattern is no guarantee for effectiveness
either. The frequently occurring pattern “was born in London” (found when query-
ing for
Thomas Bayes * England) is well-suited to be used to find London-born
persons, but in general the pattern is unsuited – since too narrow – to express the
relation between a person and his or her country of origin.
Taking these observations into account, we formulate three criteria for selecting
effective relation patterns.
1. The patterns should
frequently occur on the web, to increase the probabil-
ity of getting any results when querying the pattern in combination with an
instance.
2. The pattern should be
precise. When we query a pattern in combination with
an instance in
I
Dostları ilə paylaş: