... explicit use and of a well-defined user within brackets.Consider, for instance, the expression-identity of a chair: we use the chair to sitdown and rest, to sit down and watch a movie, to sit down and ... what to do and what not to do to meet such criteria (cf. Hackos and Redish [1998];Nielsen [1993]). We aim to achieve maximum usability with respect to a gen-eral, precise notion of use, and ... general notion of use. This iswhat we do when we ask what a house, or a hammer, is and answer with adescription telling what houses and hammers in general are used for. These are descriptions...