Adding usability : Methods for modelling, user interface design and evaluation

Abstract: Many system development projects fail to provide information systems with high usability. This thesis focuses on how to solve this problem by introducing methods for modelling, user interface design and evaluation. These methods are primarily designed to serve as complements to existing methods for systems development.Analysis of Information Utilisation (AIU) is a method for analysing and describing how information is being used in a work situation. It is performed through observation interviews with users during on-going work. User Interface Modelling (UIM) is a method for gathering user requirements relevant for the design and is to be used as a complement to use cases. These requirements are specified during sessions with users, interface designers and software engineers. The results of AIU or UIM can be used in the design process, and is especially useful when designing according to the workspace metaphor. With this metaphor, the user interface is tailored to each category of users performing work in different workspaces.To guide the design of the interface, an evaluation method is presented whereby the style (i.e. the look and feel) of the interface and the content (i.e. the substance) are evaluated separately. From a heuristic approach, usability experts evaluate the style and the content is evaluated together with the end-users. This approach to design has been applied in a case study in which AIU and UIM were used jointly to gather and specify requirements on the user interface. The workspace metaphor was used and the prototype was developed in an iterative process where the style and the content were evaluated separately in each iteration. In addition, an evaluation method aiming at identifying cognitive work environment problems caused by an information system is introduced. It is used as a complement to ordinary instruments for identifying work environment problems of a more traditional nature.The different methods have been shown to be good support for user interface design. To utilise the strength of the methods fully, a designer with usability knowledge should be involved in a user centred development process.