Transcending the Task-Artefact cycle through evolvable design: the concept of shearing layers

The paper deals with the design of cognitive artefacts. It is supported that both normative and descriptive design approaches fail to acknowledge the co-adaptation between users and artefacts; this leads to the so-called design paradox and obstructs the co-evolution of practice and artefacts. In the first section, the paper discusses the task-artefact cycle and presents examples showing that the task-artefact cycles evolve in different time scales. In the second section, we propose the notion of shearing layers as a conceptual tool for analysing the dynamics of task-artefact co-evolution and the identification of slow and faster layers. At a design level, we show how adopting the shearing layers view we may support and accelerate the practice-artefact co-evolution.