7.4 Clustering ConCepts 289
Threshold value is a designated number specified by investigators to deter-
mine the placement of an individual object or a group of objects in a cluster.
This value is used as decision criteria to determine which components of
potential clusters will be examined based on their similarities. If the similarity
measurement is larger than the threshold value, it is very likely that the com-
ponents can be placed into the same cluster and vice versa. Because of this,
the threshold value is called a critical value in some algorithms. Since threshold
values are arbitrarily set by investigators, clusters resulting from the thresh-
old value approach will be somewhat subjective. Even if it is essential for an
algor ...