Research in activity: An analysis of speed bumps as mediational means

This article traces the historical and conceptual development of what is known as activity theory, from Vygotsky and Luria, to A. N. Leont'ev, to Engeström, in order to illustrate what I see as two problems with the activity theoretic approach, especially as manifest in the work of Leont'ev and Engeström: what I call the boundary and/or focus problem and the unit-of-analysis problem. In the second half of the article, I explore the social semiotic of an everyday artifact, the "speed bump," and introduce a discovery heuristic for examining how this artifact functions mediationally in human activity. In so doing, I have tried to discover activity through principled analysis, rather than assuming activity or activity system a priori.