A social network may be defined as a set of actors (generally individuals or organizations) linked by social relations or ties of a specified type, such as friendship, kinship, flow of resources, shared interests, or group membership, to name but a few. Research carried out in various fields has shown that social networks play a central role in determining the way problems are solved, innovations are diffused, and organizations are run; social networks also play a role in the degree to which individuals succeed in achieving their goals.

A social network may be represented as a map of all of the relevant social relationships linking a group of actors. Nodes and ties are often displayed in a social network diagram, in which nodes represent the actors ...