Tuesday, May 23, 2006

Defining Stigmergy Part 1

Something I keep coming back to is 'how far can/should the term stigmergy be extended?' The concept in general seems applicable to so much of human endeavour that I am concerned that without focusing, the term risks being watered down to the point of ineffectuality.

The original definition given by French biologist Pierre-Paul Grassé in 1959 to refer to termite behaviour was: "Stimulation of workers by the performance they have achieved." From the broadest interpretation of this definition, culture itself seems to qualify as stigmergy - human workers modify our surroundings and in turn are stimulated to do more and better. However if one is to apply the term in a focused and useful manner, such a broad definition is no doubt problematic in that it leaves little scope for such distinctions as stigmergy on the internet vs. in culture etc. Never mind the fact that all organisms stimulate their brethren through the performance they have achieved at least in evolutionary terms.

So it should have come as no surprise after doing some hunting around that many researchers have addressed the issue of defining stigmergy. I discovered a nice little Power Point poster by Dylan Shell and Maja Matarić: On the use of the term ‘Stigmergy’ (.ppt). (Here's an HTML version, however it lacks all the references.) This poster shows that not only is the definition up for contest, with confusion over whether communication takes place indirectly or at all, but so is the term's etymology. Below are some variations on the terms origins (see the poster for references):

  • "‘stigma’ (goad) and ‘ergon’ (work)…” to “…stigmergy (stigma: Wound from a pointed object; ergon: Work, product of labour = stimulating product of labour).”
  • “from the Greek words stigma ‘sign’ and ergon ‘action,’ and captures the notion that an agent’s actions leave signs in the environment, signs that it and other agents sense and that determine their subsequent actions.”
  • “[F]rom the Greek stigma: sting, and ergon: work.”

Perhaps some of the more interesting research done with regards to stigmergic collaboration that is highlighted in the poster is the various categorisations thus far developed in research:

Holland and Melhuish [1999] define two subtypes:
Active: actions affect sensory inputs of others
Passive: actions affect the outcome of later actions

Bonabeau, et al. [1999], distinguish:
Qualitative: sensory inputs differ by type
Quantitative: sensory inputs differ by degree

Wilson [1975], draw the distinction between
Sematectonic: change in state result of task-related action
Sign-based: (or marker-based) result of something that makes no contribution to the task

As the authors of the poster point out, Grassé's original understanding of stigmergy then becomes further defined as: Active, Qualitative Sematectonic stigmergy - that's a mouthful. More on this in Part 2.


At 5/24/2006 8:02 PM, Blogger Michel said...


Would you agree that, as stated here, http://blog.p2pfoundation.net/?p=201
(original source: http://www.globalvillages.info/wiki.cgi?GlobalVillages/FranzNahrada/Workspace/RomeSpeech)

Stigmergy is stage 2 of peer production as defined by Franz Nahrada?

I'm quoting:

Franz Narada, the tireless promotor of the concept and practice of Global Villages, recently gave a remarkable speech that can serve as a good introduction to peer production. Particularly illuminating are his distintions regarding three phases in the development of peer production, based on the intensity of the collaboration between peers, and its relation with the for-profit mode of production.”’

1. The classical “prosumer mode”, in which everybody is working
basically for themselves in using and customizing productive abilities created or
reinforced by industrial products that enable people do use “embodied
potentials” of information and automation. Alvin Toffler has discovered
that in the eighties, but only Shosanna Zuboff recently formulated that
this will result in a “copernican shift” where the value-creation in
the classical sense is replaced by the support economy.

2. The “swarm mode in which people are loosely aggregated in doing
things, either for themselves (ebay,musicsharing) or for an external
task that uses the “least effort” way (Seti@home and successors)

3. The “community mode”, in which the team up in new forms of voluntary
social organisation. (classical example Free Software).

The interesting thing is that this three modes are pretty separated,
but there is a “hidden continuum” structurally connecting them, they become
“mutual enablers”.

Michel Bauwens, p2pfoundation.net

At 5/29/2006 5:52 AM, Blogger Mark Elliott said...

This is a tricky one to sum-up for several reasons.

Firstly: the more I look, the more difficult it is to define stigmergy in a a generalised way - see: Defining Stigermgy Part 1.

Secondly: stage 2, at least at this point, is fairly loosely defined in that a great many different methods of communication are likely to be taking place during this stage.

However, from what I understand, to qualify as stigmergy, agents cannot communicate directly with on another, but rather must engage indirectly via a medium. (The confusion here is largely I think because stigmergy was not developed to explain human interactions, but termites who have much simpler communication.) So, are we stigmergically communicating via the electronic medium of these emails, or are we communicating directly with one another in that I am addressing you and you are responding? I have a feeling both are applicable and that stigmergy is a larger area that can accommodate and account for a variety of phenomenon. After all, Pierre-Paul Grassé who coined the term gave it the definition of: "Stimulation of workers by the performance they have achieved."

So, in short, probably ;-) - that is, from a macro perspective of the swarm phenomenon. One of my central projects right now is trying to get a grasp of stigmergy as applied to human endeavours, so it would be beneficial for me to continue this discussion - both to help develop my understanding of peer production as well as stigmergy as applied to humans.

Can you recommend a good reading perhaps in your wiki that will give me a good introductory grounding in peer production - I think I have a basic understanding, however I don't want to assume...


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