Measure | Description | Reasoning | Interpretation for inter-organisational/multisectoral policy |
Network-level measure | |||
Degree | The number of ties coming from each node and/or going to each node. | Identification of highly connected actors in the network, whom people go to and who go to others | Key nodes (actors) act as leaders with power, resources and the ability to influence the network behaviour and outcomes. |
Betweenness | Nodes that link other nodes which are not linked themselves | These actors (nodes) act as a ‘bridge’ connecting people who are not otherwise connected. | Identification of betweenness nodes can facilitate collaboration between actors within a network, as these nodes act as brokers or connecters. |
Isolates | An actor not connected to anyone | Indicates actors that are not connected to others in the network. Connection to at least one other person in the group would be desired. | Ties among members of the network ensure the flow of information/resources. Identification of isolates can be useful to identify measures to engage isolated actors in the network. |
Reciprocity | The extent to which ties are reciprocated. | Indicates whether the relationships are reciprocal. | Lower reciprocity indicates weaker ties. Greater reciprocity indicates a mutual and strong relationship. |
Density | Expressed as the number of ties present divided by the number of possible ties. | Indicates cohesion in the network. | Lower density levels indicate that the network does not build ties or linkages with other actors. Ties are required for the flow of information or resources in the network. |
Centralisation | The extent to which the network is focused on one or a few actors. | A centralised network indicates that one or few actors capture an important position. Actors that are highly central act as a resource in the network (please see degree). | Higher centralization means that information and resources flow through one or few actors. To increase network functionality, engagement of key actors is necessary or requires decentralisation. Freeman’s normalised network centralization can be used to compare across networks. |
E-I index | The E-I index takes the number of ties of group members to outsiders, subtracts the number of ties to other group members, and divides by the total number of ties. | The extent to which actors communicate with others within (homophily) vs outside (heterophily) their group. | Indicates intragroup communication and exchange, related here to communication across departments/sectors. The value ranges from-1 (homophily/all ties are internal to the group) to +1 (heterophily/all ties are external to the group). |
E-I, external–internal.