Designing time at the user interface

This paper describes research that seeks to facilitate the capture, represe ntation, and reasoning about, temporal information by usability engineers. The product, a method we call KAT-LITTER, is an extension of Johnson and Jo hnson's (1991) Knowledge Analysis of Tasks (KAT). An evaluation of KAT-LITT ER showed that it influenced the design process in two significant ways: fi rstly, designers using KAT-LITTER spent more time reasoning about temporal issues than designers using KAT alone, and secondly these same designers co nsidered a broader spectrum of temporal issues. Further developments of KAT -LITTER are briefly discussed.