Stigmergy and Mutualism in Learning Teams: the STiMUS Agent-Based Model and its Application to Instructional Design

This paper presents STiMUS (Stigmergy and Mutualism in Socio-Technical Systems), an agent-based model implemented in NetLogo 7.0. The model formalises two complementary coordination mechanisms in digital project teams. The first is stigmergy: contributor agents select shared artefacts to work on by following traces left by previous editors, without explicit communication. The second is mutualism: artefacts and contributors mutually reinforce each other through repeated interaction — the richer the artefact, the higher the motivation to engage with it, and the more engagement, the richer the artefact. A factorial experiment (BehaviorSpace, 1440 runs) demonstrates that contrasting configurations of team behaviour emerge reproducibly under specific combinations of two independent control parameters: the transparency of the shared object environment and the degree of task structuring. Both parameters have direct pedagogical analogues. A pedagogical configuration map is proposed that enables an instructor observing a team's digital-trace profile to make evidence-based adjustments to the collaborative learning scenario.