Social Positions and Simulation Relations

• Describing social positions and roles is an important topic within the social network analysis. Identifying social positions can be difficult when the target organization lacks a formal structure or is partially hidden. One approach is to compute a suitable equivalence relation on the nodes of the target network. Several different equivalence relations can be used, all depending on what kind of social positions that are of interest. One relation that is often used for this purpose is regular equivalence, or bisimulation, as it is known within the field of computer science. In this paper we consider a relation from computer science called simulation relation. The simulation relation creates a partial order on the set of actors in a network and we can use this order to identify actors that have characteristic properties. The simulation relation can also be used to compute simulation equivalence which is a related but less restrictive equivalence relation than regular equivalence that is still computable in polynomial time. We tentatively term the equivalence classes determined by simulation equivalence social positions. Which equivalence relation that is interesting to consider depends on the problem at hand. We argue that it is necessary to consider several different equivalence relations for a given network, in order to understand it completely. This paper primarily considers weighted directed networks and we present definitions of both weighted simulation equivalence and weighted regular equivalence. Weighted networks can be used to model a number of network domains, including information flow, trust propagation, and communication channels. Many of these domains have applications within homeland security and in the military, where one wants to survey and elicit key roles within an organization. After social positions have been calculated, they can be used to produce abstractions of the network—smaller versions that retain some of the most important characteristics.

Ämnesord

NATURVETENSKAP  -- Data- och informationsvetenskap -- Datavetenskap (hsv//swe)

NATURAL SCIENCES  -- Computer and Information Sciences -- Computer Sciences (hsv//eng)

Nyckelord

Social network analysis

Social positions

Abstraction

Simulation equivalence

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)