Evaporation

There is one further feature of a stigmergic environment that needs to be emphasised. This is its impermanence. Stigmergic environments are designed to be short-lived, continuously self updating through a process of evaporation. For instance, when an ant lays a trail of pheromones across a landscape, the pheromones last for only a short time before they evaporate. This ensures that recent pheromone trails are not confused with older pheromone trails Ð which might relate to circumstances that have changed.

This is a critical element in the design of a stigmergic system. Any records deposited in a people space would have to be given an appropriate "life span" such that they "die" after the elapse of a certain period of time. This safe guards the environment against getting cluttered up with out of date information. This solves for the problems of obsolescence and redundancy, envisaged by the database expert, Vahe Kassardjian, at the beginning of this chapter.