Databases Reference
In-Depth Information
were getting good at making large-scale computations on large
datasets.
Social network analysis was germinated by
Harrison White
, professor
emeritus at Columbia, contemporaneously with Columbia sociologist
Robert Merton
.
Their idea was that people's actions have to be related
to their attributes, but to really understand them you also need to look
at the networks (aka systems) that
enable them to do something
.
How do we bring that idea to our models? Kelly wants us to consider
what he calls the micro versus macro, or individual versus systemic
divide: how do we bridge this divide? Or rather, how does this divide
get bridged in various contexts?
In the US, for example, we have formal mechanisms for bridging those
micro/macro divides, namely markets in the case of the “buying stuff ”
divide, and elections in the case of political divides. But much of the
world doesn't have those formal mechanisms, although they often have
a fictive shadow of those things. For the most part, we need to know
enough about the actual social network to know who has the power
and influence to bring about change.
Terminology from Social Networks
The basic units of a network are called
actors
or
nodes
. They can be
people, or websites, or whatever “things” you are considering, and are
often indicated as a single dot in a visualization. The relationships
between the actors are referred to as
relational ties
or
edges
. For ex‐
ample, an instance of liking someone or being friends would be indi‐
cated by an
edge
. We refer to pairs of actors as
dyads
, and triplets of
actors as
triads
. For example, if we have an edge between node A and
node B, and an edge between node B and node C, then
triadic closure
would be the existence of an edge between node A and node C.
We sometimes consider
subgroups
, also called
subnetworks
, which
consist of a subset of the whole set of actors, along with their relational
ties. Of course this means we also consider the
group
itself, which
means the entirety of a “network.” Note that this is a relatively easy
concept in the case of, say, the Twitter network, but it's very hard in
the case of “liberals.”
We refer to a
relation
generally as a way of having relational ties be‐
tween actors. For example, liking another person is a relation, but so
