This study is an example of cluster analysis. The cluster examination or clustering is the task of combining a set of objects in such a way that objects in the same group are more alike to each other than to those in other groups. The persistence of cluster analysis is to place objects into groups, or clusters, suggested by the data, not well-defined a priority in which such that objects in a given cluster incline to be alike to each other in some sense and objects in different clusters incline to be different.
