http://tc.eserver.org/dir/Articles/Documentation/Usability/History A listing of the most recently indexed works about Articles and Documentation and Usability and History in the field of technical communication. en-us Copyright (c) 2005-08 by the EServer. All rights reserved. tclib-editorial@eserver.org (TC Library Editorial Board) webmaster@eserver.org (Geoffrey Sauer) http://tc.eserver.org/images/newlogo.gif http://tc.eserver.org/dir/Articles/Documentation/Usability/History http://tc.eserver.org/29049.html http://tc.eserver.org/29049.html Traditional models of usability assume that usability is a quality that can be designed into a particular artifact. Yet constructivist theory implies that usability cannot be located in a single artifact; rather, it must be conceived as a quality of the entire activity in which the artifact is used. This article describes a distributed approach to usability, based on activity theory and genre theory. It then illustrates the approach with a four-decade examination of a traffic accident location and analysis system (ALAS). Using the theoretical framework of genre ecologies, the article demonstrates how usability is distributed across the many official and unofficial (ad hoc) genres employed by ALAS users.