Basics of Network Theory for Social network analysis - Part 2

Part 1 of this blog post gave a basic introduction to social network analysis.

As covered in the previous post Link to the Part 1 a social network diagram in its simplest form consist of node and ties, where nodes are the points and ties are the lines.

Basic social network showing Nodes and Ties

Now I shall get a little deeper into the by exploring the properties of tie’s.

Tie Directionality

A tie is said to be directed or directional if there is a flow between the nodes. For example, if Node A recommends a product or service to Node B, then the tie that connects them is directional. It is important to note that a tie is not always directional. For example if there is no flow between the nodes but, Nodes A and B share a association of some sort, they may share residence in the same country (Ireland for example) then the tie is non-directional or not directed. Therefore, if the tie is based on an affiliation or association then the tie is non-directional or not directed.

Tie Reciprocity and Symmetry

If the tie is directional, then you need to ask the question is this flow or directionality symmetrical or reciprocal? Does advice/information flow from Node A to Node B only, or is the flow between each Node? In the latter case it is reciprocal (or symmetric). This property is quite important to identify opinion leaders within a group; where the a flow is not symmetric. This property is also useful in ensuring that there is cooperation within a group, for this condition you would expect the ties to be quit symmetric.

Tie Multiplexity

This property describes multiple relationships between actors (nodes), the tie is therefore multi-layered or multi-dimensional. The exmaple below shows Node A “asking advice” from Node B, and Node B “paying respect” to Node A.

Tie Strength

The strength of tie refers to the intensity and tightness of a tie. This may be represent the level love (or hate) between two countries. It should be noted that tie strength, therefore, is not a binary on or off state, but, is a variable measurement. Van Den Bulte and Wuyts (page 10, 2007) conceptualise tie strength as having two dimensions, (1) tie intensity or activity (the frequency of contact) and (2) tie valence (the affective, supportive, or cooperative character of the tie) and they state that this conceptualisation of tie strength agrees with best empirical evidence to date. Mark Granovetter (1973) first introduced the “Strength of weak ties” where acquaintances are weak ties and our friends are strong ties. He concludes that Strong ties share the same limited information while weak ties are a source of new information and thus are more valuable. Van Den Bulte and Wuyts (page 16, 2007) concludes that tie strength can be conceptualised as having two dimensions, tie intensity or activity (the frequency of contact) and tie valence (the affective, supportive or cooperative character of a tie.)

Tie Homophily

This property describes the tendency for like minded actors (nodes) to connect and mingle with like minded others. The reason this property has gained importance is that it constains actors’ social worlds. There is a negative side to homophily, which is it can cause the actor within a group to ignore new ideas, which often occurs in Brand Communities. On the positive side, it can foster trust and reciprocity between actors in a group.

References:
Van Den Bulte, C., Wuyts, S. 2007, Social networks and Marketing, Marketing Science Institute .
Granovetter, M (1973), The strength of weak ties, American Journal of Sociology.