Reflection in self-organised systems - Information Systems Foundations: Constructing and Criticising - page 107

biological, physical and social self-organising systems. However, there are qualities
unique to each of these systems and their correspondent environments.
Stigmergy
The term 'stigmergy' was originally proposed in 1959 by the French scientist, Grasse,
in his study of social insects, and more specifically, while observing termite building
behaviour. Grasse's stigmergy definition, as translated by Holland and Melhuish (1999,
p. 2), indicates that:
'… the coordination of tasks and the regulation of constructions does not de-
pend directly on the workers, but on the constructions themselves. The
worker does not direct his work, but is guided by it. It is to this special form
of stimulation that we give the name Stigmergy (stigma, wound from a pointed
object; ergon, work, product of labour = stimulating product of labor)'
This means that stigmergy describes the influence that information, derived from the
local environmental effects of the activities of previous individuals, has on the current
individuals' behaviour.
Camazine, et al.(2001) refer to stigmergy as the process of information gathering from
work in progress. In other words, working stimulus comes from the information gathered
when individuals interact with environmental effects rather than from fellow workers.
This is a further step in communication and cooperation among individuals of a system.
As Camazine, et al.(2001, p. 24) describe it, in continuing with the social insect analogy:
'… instead of coordination through direct communication among nestmates,
each individual can adjust its building behaviour to fit with that of its nestmates
through the medium of the work in progress '.
Stigmergy appears to be an important mechanism that assists a system to structure itself
through the collective behaviour of individuals within the system's environment. An
individual could move through the environment, gathering or emitting information,
but it can also interact with the environment. Both actions could be considered stigmergy.
Self-organisation is made possible by the coordination of activities that over time and
space creates a pattern of construction. Stigmergy is effective in coordinating these
construction activities and also in mediating interactions among workers through the
environment. For that reason, it is an important component of self-organisation. However,
it appears that stigmergy is not a complete explanation of such construction activities
since there is no explanation of how construction ends, nor how errors made during
construction are amended.
Stigmergy can explain the simpler aspects of transfer of information among individuals,
where each individual needs to determine what to do and where a direct line of inform-
ation from one individual to another individual does not exist; transfer instead occurs
through the stimulus of previous individuals' information and construction activities
embedded in the environment. Figure 9.3 summarises this process. Here the work pre-
viously accomplished by one or more individuals is imprinted in the environment as a
cue and stimulus for other individuals. Thus individuals can interact socially by indirect
transfer of information encountered in the environment through constructs made by
others of their kind.