Public access to environmental information is now a common requirement by national, international and European Union legislation. It is widely recognized that web-based GIS can enhance access to environmental information and can support public participation in environmental decision-making. Yet when these systems are used by non-experts might be challenging because of the GIS complexity. Considerations about data accuracy and errors during the analysis further increase the elements of risk, complexity and uncertainty, which are preconditions of trust. Many lay users are partially aware of the technicalities related to spatial data handling.
Thus, the issue of trust in such systems, and how user’s trust is built is an important consideration. Online trust has been repeatedly identified as a major concept for online information systems and its value recognised, especially in the context of e-commerce, as it influences the intentions to engage, the use and acceptance of online systems and the overall User Experience. However, there is very limited, if at all, knowledge about how trust is constructed in web-mapping systems.
To improve knowledge in this domain, this paper describes the concept of online trust and its characteristics and models developed in different fields. The UK Environment Agency ‘What’s In You Back Yard’ (WIYBY) website is examined using techniques derived from the Human-Computer Interaction field. A Heuristic Evaluation and a Cognitive Walkthrough were undertaken by three evaluators, to identify what influences trust and how perceived trustworthiness can be enhanced through interface design. Trust cues suggested in the literature were also considered for their applicability and relevance in web-mapping. Based on the findings a set of guidelines is presented which covers the dimensions of graphic, content, structure, map functionality and trust-cue design.