Social Media Mining: An Introduction

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CUUS2079-06 CUUS2079-Zafarani 978 1 107 01885 3 January 13, 2014 17:15

Community Analysis 143

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Figure 6.1. Zachary’s Karate Club. Nodes represent karate club members and edges
represent friendships. A conflict in the club divided the members into two groups. The
color of the nodes denotes which one of the two groups the nodes belong to.
graphs is a convenient way to depict communities because color-coded
nodes can denote memberships and edges can be used to denote relations.
Furthermore, we can observe that individuals are more likely to be friends
with members of their own group, hence, creating tightly knit components
in the graph.
Zachary’s Karate Club is an example of twoexplicit communities.An EXPLICIT
(EMIC)
COMMUNITIES
explicit community, also known as anemiccommunity, satisfies the fol-
lowing three criteria:

1. Community members understand that they are its members.


2. Nonmembers understand who the community members are.


3. Community members often have more interactions with each other
   than with nonmembers.

In contrast to explicit communities, in implicit communities, also known IMPLICIT

(ETIC)

COMMUNITIES

aseticcommunities, individuals tacitly interact with others in the form of an

unacknowledged community. For instance, individuals calling Canada from

the United States on a daily basis need not be friends and do not consider

each other as members of the same explicit community. However, from the

phone operator’s point of view, they form an implicit community that needs

to be marketed the same promotions. Finding implicit communities is of