The Human-Artifact Model: An Activity Theoretical Approach to Artifact Ecologies

While devices of all shapes and sizes currently dominate the technological landscape, human-computer interaction as a field which is not yet theoretically equipped to match this reality. In this paper we develop the Human-Artifact Model, which has its roots in activity theoretical HCI. By reinterpreting the activity theoretical foundation, we present a framework that helps addressing the analysis of individual interactive artifacts, while embracing that they are part of a larger ecology of artifacts. We show how the Human-Artifact Model helps structuring the understanding of an artifact's action-possibilities in relation to the artifact ecology, surrounding it. Essential to the model is that it provides four interconnected levels of analysis and addresses the possibilities and problems at these four levels. Artifacts and their use are constantly developing, and we address development in, and of, use. The framework needs to support such development through concepts and methods. This leads to a methodological approach that focuses on new artifacts to supplement and substitute existing artifacts. Through a design case, we develop the methodological approach and illustrate how the Human-Artifact Model can be applied to analyze present artifacts and to design future ones. The model is used to structure such analysis and to reason about findings, while providing leverage from activity theoretical insights on mediation, dialectics and levels of activity.