Table 1 Common brokerage terms, features and motivations.

Boundary spanner

Bridges the structural hole between two clusters conceptualised as being separated by a boundary of some sort, e.g. outside the network or department

To overcome a boundary and facilitate communication / knowledge flow across it.

[17, 18]

Bridge

Bridges the structural hole between two clusters

To include outsiders in information flows or achieve coordination.

[5, 19]

Broker

Acts as an intermediary between two unlinked actors / clusters

To facilitate some transaction, resolve a conflict or increase personal power or social capital.

[18, 20–22]

Broker in a Structural fold

The broker is the common actor in two overlapping, cohesive clusters

To be an engaged member of two groups. Tends to be disruptive as loyalties may be seen to be divided.

[23]

Consultant / cosmopolitan / itinerant broker

Links two alters in an outside cluster/s who are not directly linked

To facilitate negotiations between alters or seek to exploit their separation.

[21, 22]

Co-ordinator

Links alters within their own cluster who are not linked directly

To improve coordinated effort or to centralise knowledge exchange.

[21, 22]

Gatekeeper

Bridges the structural hole between their cluster and an outside cluster, controlling what information passes into or out of their cluster

Often associated negatively with a hoarding of information, or positively bringing useful information / filtering out irrelevant information.

[21, 22, 24]

Go-between

Stands between two unlinked actors offering some service, e.g. facilitating access to advice, resources

Usually facilitative but can result in work overload for actor or information bottlenecks.

[25, 26]

Information or knowledge broker

Keeps separate groups in a network co-ordinated or informed

To improve network information flows and prevent fragmentation.

[18]

Liaison

Bridges the gap between two different outside clusters without having prior allegiance to either

To facilitate negotiations between alters – often a commercial transaction.

[21, 22]

Mediator / conflict resolver

Seeks to increase understanding between two parties separated by a mismatch of knowledge, expectations, culture etc.

To resolve conflict between parties - role often held by actor familiar with both sides.

[15, 27, 28]

Peripheral specialist

Holder of specialised knowledge that tends to occupy peripheral positions

To be available for consultation yet still devote time to their specialty.

[18]

Representative

Bridges the gap between another actor from the same cluster and an actor from an outside cluster

To facilitate external contact - may be a delegated negotiator.

[21, 22]

Tertius gaudens (the third who enjoys)

A brokerage strategy to keep alters apart

To increase broker’s personal social capital or power.

[5, 27]

Tertius iungens (the third who joins)

A brokerage strategy to join alters together

To increase network performance.

[29, 30]