“Signs” is the sign: Towards a unified view of stigmergy

Stigmergy is widely used in MAS. However, its specific meaning has not been fully developed yet; it varies from different view. In this paper, we picked up ldquosignrdquo as a key notion to understand it. Sign is given by agents, represented by environment, and sensed by others. Therefore, sign is the link of all the components in a stigmergic MAS. Based on this understanding, we propose a definition that reveals the nature of signs and exploit the significations and relationships carried by the notion of sign. Then, a sign-based model of stigmergy, SBMS, is consequently reached, which captures the essential characteristics of stigmergy. The notion and the model give a unified view of stigmergy. Based on them, the taxonomy and some viewpoints of stigmergy are illustrated. We conclude that the preliminary taxonomy is based on the characteristics of the sign. And the various view of stigmergy is the generality, the speciality or an aspect of SBMS.