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“4137X˙CH05˙Akerkar” — 2007/9/8 — 11:01 — page 187 — #11
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5.2 Statistical Methods 187
5.2.2 Other Methods
5.2.2.1 Probabilistic Clustering
There are some differences between partition-based clustering and probabilistic clustering.
The idea for the partition-based algorithm is that if a point belongs to a cluster, it belongs
exclusively to that cluster. Probabilistic clustering, on the other hand, permits a point x to
have partial membership in a cluster.
The idea behind the partition-based algorithm does lead to some problems. In the graph
in
Figure 5.11, point x has the same distance from c
i
and c
j
, so it is unfair to let it belong
exclusively