Understanding Usability Issues in a Public Digital Library

Designers often design for themselves unless they are trained to realise that people are diverse, and that users are unlikely to be like them. The more errors that can be avoided “up front” by the right method, the less work both test-users and designers will have to put in to refine prototypes to improve their usability. Landauer (1995) points out that it is not good enough to design interactive systems without subjecting it to some form of evaluation, because it is impossible to design an optimal user interface in the first attempt. Dix Finlay, Abowd, and Beale (1998) argue that even if one has used the best methodology and model in the design of usable interactive systems, one still needs to assess the design and test the system to ensure that it behaves as expected and meets users’ requirements. Nielsen’s (1993) advice with respect to interface evaluation is that designers should simply conduct some form of testing. As digital libraries (DLs)—interactive systems with organised collections of information—become more complex, the number of facilities provided by them will increase and the difficulty of learning to use these facilities will also increase correspondingly. Like the Web, DLs also provide non-linear information spaces in which chunks of information are inter-connected via links. However, they are different in character from the Web in several important respects: a DL represents a collection for a specific purpose containing text-based and/or geospatial content and has search strategies that are clearly defined and more powerful. After a decade of DL research and development, DLs are moving from research to practice, from prototypes to operational systems (Borgman, 2002). In the digital world, real world cues such as face-to-face interactions with human librarians and thumbing through hardcopy books have been replaced by drop-down menus, search screens, and Web page browsing. In DLs, users must map their goals onto DLs’ capability without the assistance of a human librarian. As a result, wide acceptance of DLs will only be achieved if they are easy to learn and use relative to the perceived benefit (Borgman, 2000).