C.P.J.M. van Elzakker1, P.J.M. van Oosterom2, I. Delikostidis1

1 - International Institute for Geo-Information Science and Earth Observation (ITC), Enschede, the Netherlands

2 - Delft University of Technology, the Netherlands



The use of geo-information in mobile devices (smartphones, PDA's) is constantly increasing. Map displays play a prominent part in this, although they suffer from limitations set by the small screens, storage capacity and processing power of these devices. With the availability of high bandwidth wireless connections it should be possible to overcome some of these limitations and up-to-date map displays may be generated at the right level of detail and adjusted to the needs of the users. In this context, a Dutch research project started in 2006 with User-Centered Design (UCD), generalization and mobile geo-applications as keywords (see http://www.gdmc.nl/uwsm2/).


Generalization is particularly relevant for mobile geo-applications. Not only because zooming is a very important way of interaction of users with the map interface, but also because the progressive transfer of geo-information from server to device may be beneficial to usability (e.g. first retrieve 'rough' representations and get additional detail when required). With smooth zooming, realized through progressive transfer, map scale may change continuously in an animation style of visualization. This may help users to orient themselves. Part of the research deals with the application of the GAP-face tree / GAP-edge forest concepts in variable scale topological data structures suitable for progressive data transfer.


These concepts will be implemented in prototypes of mobile geo-applications that will be developed through UCD techniques. One of the use cases, for which use scenarios are developed in UML, is a service for users who want to park their cars in Amsterdam. After the first prototypes have been developed, their usability will be evaluated.


The paper that will be presented at ICC 2007 in Moscow is mainly related to the research Work Package "Prototype evaluation". It will contain an overview of research methods and techniques that have already been used in testing the usability of existing mobile geo-applications as well as those that have not been used before but demonstrate great potential. The outcome is a proposed methodology for the usability evaluation of mobile geo-application prototypes, and particularly the map displays thereof. This proposal has been put into practice with mobile geo-applications that are comparable to the prototypes that are under development in the main research project and the paper reports on the results. They are used to adjust the proposed methodology which may then be applied by all who are involved in the testing of the usability of the interactive map displays in mobile geo-applications.