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Table 1 Glossary of complexity and social network terms

From: Building a learning community of Australian clinical genomics: a social network study of the Australian Genomic Health Alliance

Complexity terms

 Agents

Individual components that make up a system; people who act independently in social systems. Here they are the individual members of Australian Genomics.

 Complex adaptive system (CAS)

Term used for a collection of agents that interact dynamically and whose interactions and interdependencies may lead to learning, adaptation and emergent behaviours.

 Phase transition

A time when the system undergoes a crucial change or reaches a tipping point in which a significant transformation in how agents are organised or interact starts. This can alter the system, or the context in which the agents operate.

 Self-organisation

The tendency for agents in a CAS to interact in certain ways and form semi-formal groups without undue outside direction.

Social network terms

 Betweenness centrality

A measure of the influence of an actor in connecting others in the network. Actors with high betweenness centrality lie most often on the shortest path between other nodes. Betweenness centrality positions the actor to be a go-between or broker.

 Centralisation

A network measure that shows how dominated the whole network is by one or more nodes in terms of their ties. Low centralisation indicates a more even distribution of ties.

 Density

The proportion of ties found across a network per the number of possible ties. Expressed as a number between 0 and 1.0, when 1.0 means all possible ties are present (everyone is connected to everyone else).

 In-degree

Number of ties directed to a node, i.e. the number of times a particular individual is nominated by others as having that relationship with them. A measure of influence, importance or accessibility.

 Nodes

Agents or individuals. Depicted as points or small circles in sociograms

 Out-degree

Number of ties a particular node directs to other nodes, i.e. the number of other people a particular individual nominates as having that relationship to them. A measure of connectedness.

 Sociogram

A graphical depiction of the relationship data in a social network study collected from individuals and then collated. Based on graph theory, parameters can be computed from the aggregated data.

 Ties

The relationship of interest in a social network study. Depicted as a line between nodes. Two nodes are said to be tied if one or both acknowledge the relationship.