ABSTRACT
Software design methodologies prescribe a set of representations that have to be produced and methods for deriving those representations. These formally defined methods tend to be used when the design team is large, i.e., 20 or more people, and may serve a management function. The techniques described in this chapter fit Nielsen's requirements for discount techniques. They are lightweight procedures that can be learned in a day or so and only take man-days to apply. The chapter describes four representations for reasoning about the users' needs. The representations are: a rich picture to capture top level concerns; a work objective decomposition (WOD) that serves a similar purpose to a hierarchical task analysis but is easier to produce and use; a user exceptions list of possible interruptions and mistakes, and fictional scenarios of use generated from the WOD and user exceptions list. They allow developers to develop their understanding as a group and to check their understanding with their informants.
