Social
network analysis is a kind of research methods studying the relationship
between a group of actors. A group of actors can be people, communities,
groups, organizations, countries, etc.. The phenomenon and data reflecting from
their relationship model is the focus of the network analysis. From the
perspective of social network, the interaction among people expressed in social
environment can be viewed as a model or rules based on the relationship, and the
regular pattern based on such relationship reflects the social structure. The quantitative
analysis about this structure is the starting point of social network analysis.
In
social network analysis, there are some important concepts, which include
degree, closeness and centrality. With the help of these concepts, we can get
more useful information through the social network.
Degree is used to describe the number of edges connected to the vertexes
in graphs. The degree of an actor can show the number of ties he has in a
social network and the number of people he is connected to. Depending on this
data, we might conclude the importance of this actor among other people.
Closeness is another important concept referring to the extent to which
an actor is close to all other people in the social network. There maybe more
than one path between two vertexes and we only consider the shortest one. By
adding all of the shortest distance from one vertex to all other ones and
inversing the answer, we get the closeness of this vertex.
Centrality is the measure of relative importance of an actor in a social
network. It can be measured by many methods. One of them called betweenness
centrality is defined by the number of shortest paths in the network that pass
through one vertex. Betweenness centrality can reflect the importance of an
actor in a social network. If an actor with high betweenness centrality is
removed, many shortest paths will be altered at the same time.
There
is a proverb which is “Will matter is not what you know, but who you know.” briefly
and aptly explaining what social network analysis actually means, I think.
