Task-Oriented Usability Evaluation of a WebGIS for a Real-World Community

Article excerpt

INTRODUCTION

In recent years, online geospatial systems for people who are not experts in the domain of spatial information science have emerged. For many of these systems, however, the data representation and the way of interacting with this data were inspired by systems that were created for expert users such as ArcGis, MapInfo, or Manifold.

The usability of these expert systems has been evaluated and criticized by several groups of researchers (Traynor and Williams 1995), but few researchers have yet explored whether data representation and interaction manners, taken from expert systems, are applicable to spatial information systems that are not used by experts.

Despite the fact that major online Web-mapping systems such as Google Maps or Microsoft Live Search have been significantly improved regarding their usability, systems implemented for specific groups of users still lack such improvements. One reason for this problem might be that many of these systems are based on components that already have predefined interaction manners built in and that only offer a certain set of possibilities for data representation. Another reason is that, up until now, almost no specific usability guidelines exist for online geospatial systems that are built for specific groups of users such as real-world communities (Haklay and Zafiri 2008).

Usability engineering as a field within human-computer interaction was founded in the 1980s and has become a well-established discipline since then, yet we argue that usability testing for geospatial systems is different from usability testing of other software applications. The difference is rooted in the fact that both the data displayed in a geospatial system and the interface that allows for spatial interaction are particular: The spatial information that a user is interacting with is an abstract depiction of the real world; the user needs to match this abstract depiction with his or her internal, cognitive map to understand it. Moreover, the interface that allows for interacting with spatial information (e.g., spatial navigation or adding spatial information) should take into account the relationship with the interaction with the real world. These facts stress the importance of both a geospatial system's interface and the depiction of the data itself. Therefore, the usability testing of geospatial systems includes not only the testing of an interface according to common usability measures (such as task completion time or errors), but implicates a deeper understanding of the interaction and the user.

Systems for real-world communities especially are an important research subject and challenge for geospatial science. Furthermore, this field of research needs to be addressed with evaluations involving members of the real-world community rather than with theoretical concepts (Jankowski and Nyerges 2003). Actual evaluations are necessary to find a methodology that proves to work for real-world communities.

Systems implemented for specific groups of users do only as much or as little as they are designed for. Yet each user perceives and uses them differently. These differences depend on several factors, such as specific interface features and previous knowledge and experience. Previous knowledge and experience particularly are reasons why it is important to take user context into account before, during, and after the implementation of a system.

In this paper, we describe the first phase of a research program aimed at responding to these immediate and larger challenges for GIScience and their relationship with nonexpert users as new modes of interaction become possible through new software tools.

To start making progress in a concrete and meaningful way, this research phase focused on a specific real-world application concerning a community of winegrowers in the Swiss canton of Vaud. Responding to spatial knowledge acquisition and spatial planning needs, a Web-delivered geospatial information tool was deployed and evaluated. …