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Social Network Analysis (SNA)
| Sentinel Visualizer
integrates Social Network Analysis (SNA) directly into
your link chart so you can quickly generate SNA metrics
on your data. Generate the raw data and see it visually
all without programming! Some of the key concepts of
Network Metrics come from the field of Social Network
Analysis (SNA). SNA provides a set of methodologies and formulas
for calculating a variety of criteria that map and measure the
links between things. Using Social Network Analysis, you can get
answers to questions like:
- How highly connected is an entity within a network?
- What is an entity's overall importance in a network?
- How central is an entity within a network?
- How does information flow within a network?
SNA provides a rich set of metrics, many of which are used in
the Sentinel Visualizer Network Metrics functionality.
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Highlights
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Social Network Analysis is directly integrated
into the Sentinel Visualizer product. |
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Quickly perform Social Network Analysis on your
data. |
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Use SNA without the cumbersome interfaces from
academic programs. |
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Sentinel Visualizer is a desktop application
that installs quickly and easily. |
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Seamless import and export of data, including
Access, Excel, Text, PDF, HTML etc. |
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Degree Centrality
Degree centrality is simply the number of direct
relationships that an entity has. An entity with high degree
centrality:
- Is generally an active player in the network.
- Is often a connector or hub in the network.
- s not necessarily the most connected entity in the
network (an entity may have a large number of relationships,
the majority of which point to low-level entities).
- May be in an advantaged position in the network.
- May have alternative avenues to satisfy organizational
needs, and consequently may be less dependent on other
individuals.
- Can often be identified as third parties or deal makers.
In our example network diagram above, Alice has
the highest degree centrality, which means that she is quite
active in the network. However, she is not necessarily the most
powerful person because she is only directly connected within
one degree to people in her clique—she has to go through Rafael
to get to other cliques.
Betweenness
Centrality
Betweenness centrality identifies an entity's
position within a network in terms of its ability to make
connections to other pairs or groups in a network. An entity
with a high betweenness centrality generally:
- Holds a favored or powerful position in the network.
- Represents a single point of failure—take the single
betweenness spanner out of a network and you sever ties
between cliques.
- Has a greater amount of influence over what happens in a
network.
In the example above, Rafael has the highest
betweenness because he is between Alice and Aldo, who are
between other entities. Alice and Aldo have a slightly lower
betweenness because they are essentially only between their own
cliques. Therefore, although Alice has a higher degree
centrality, Rafael has more importance in the network in certain
respects.
Closeness
Closeness centrality measures how quickly an entity can
access more entities in a network. An entity with a high
closeness centrality generally:
- Has quick access to other entities in a network.
- Has a short path to other entities.
- Is close to other entities.
- Has high visibility as to what is happening in the network.
As with the betweenness example, Rafael has the highest
closeness centrality because he can reach more entities through
shorter paths. As such, Rafael's placement allows him to connect
to entities in his own clique, and to entities that span
cliques.
Note: If the network contains any entities that are
un-linked (i.e. not linked to any other entities), the Closeness
value for all entities in the network is 0. This is due to
formulas and algorithms established in Social Network Analysis.
Eigenvalue
Eigenvalue measures how close an entity is to other highly
close entities within a network. In other words, Eigenvalue
identifies the most central entities in terms of the global or
overall makeup of the network. A high Eigenvalue generally:
- Indicates an actor that is more central to the main
pattern of distances among all entities.
- Is a reasonable measure of one aspect of centrality in
terms of positional advantage.
In this example, we can see that Alice and Rafael are
closer to other highly close entities in the network. Bob
and Frederica are also highly close, but to a lesser value.
Hub and Authority
Entities that many other entities point to are called
Authorities. In Sentinel Visualizer, relationships are
directional—they point from one entity to another. If an
entity has a high number of relationships pointing to it, it
has a high authority value, and generally:
- Is a knowledge or organizational authority within a
domain.
- Acts as definitive source of information.
Hubs are entities that point to a relatively large
number of authorities. They are essentially the mutually
reinforcing analogues to authorities. Authorities point
to high hubs. Hubs point to high authorities. You cannot
have one without the other. Using Social Network
Analysis in Sentinel Visualizer
Take a look at the following network:
From a visual standpoint, some clusters and centrality are
visible. But the density of information makes it difficult to
see all the centrality aspects. Sentinel Visualizer makes Social
Network Analysis available with just a single click of a button.
With any link chart visible, simply press the [Calculate] button
and the program instantly calculates the Social Network Analysis
Metrics for the items on the chart.
Now you can see centrality measures that clearly show the most
central nodes in the network. You can sort by any Social Network
Analysis number, or click on any node to find its place in the
network. You can use the Gradient Metrics to
instantly map Social Network Analysis Values to the graphic
display. Simply click on any of the available metrics and
Sentinel Visualizer color-codes each node on the network. Here
is the same graph but with Gradient Metrics showing Closeness
Centrality.
Going Further
Only Sentinel Visualizer makes it easy to apply
the power of Social Network Analysis to your data. Use it to
find hidden meaning, patterns, and trends in any data set.
Try it For Free
Contact us for a
free, 45 day trial of Sentinel Visualizer |
