Communities

Analyze the following statements about the Agglomerative (Ravasz) and Divisive (Girvan–Newman) hierarchical clustering algorithms, and determine whether each statement is True (T) or False (F):

 1) The Agglomerative algorithm starts by treating each node in the network as an individual community and repeatedly merges the most similar communities until a stopping condition is reached. This stopping condition occurs when the density inside each community becomes maximal.

2) The Divisive algorithm follows a top-down strategy: it initially treats the entire network as a single community and progressively splits the network into smaller communities.

3) The result of the Agglomerative algorithm can depend on the linkage criteria adopted, such as single, complete, or average linkage.

4) In the Girvan–Newman algorithm, communities are identified by iteratively removing links with high centrality, since these links are more likely to connect different communities.

5) In the Agglomerative hierarchical clustering, once two communities are merged, the algorithm may later separate them again if a stronger similarity pattern is detected.

Choose the correct alternative:

A) F-T-T-F-F

B) F-T-T-T-F

C) F-T-T-T-T

D) T-T-T-F-F

E) None of the above

Original idea by Gabriela Caspa