[ 11] The Mobile Spatial Interaction (MSI) Initiative, http://msi.ftw.at

sets are sold globally.

To realize MSI applications and services, the strongest challenge is how to conceptualize and design applications that are tailored to the needs of mobile users. In this respect, the following things need to be considered:

Dealing with uncertainty. MSI applications are subject to many kinds of uncertainties: GPS, sensor inaccuracies, or incorrect geo-tags. There are also technical and design issues provoked when the user moves from indoors to outdoors. These certainties cannot always be avoided, and there is a need to ensure transparency and communicate these inaccuracies to the user.

Display of spatial information.

Given the plethora of different standards and communication interfaces for mobile devices, as well as a range of varying computing power available in the devices, it will be quite difficult to design in global terms. Presenting spatial information and various details about the location and the people in the location without provoking cognitive overload is an interesting and challenging interaction-design task. To increase the bandwidth and flexibility of information display, the speech and sound-output capabilities of mobile devices should be exploited to a larger degree.

Social disclosure and privacy.

There are challenges in how we go about protecting individual privacy—not only in meeting legislative and safety requirements, but also in being sensitive to what users want and do not want to make available about their present location. Designing with these issues in mind is complex. For example, a shop in the vicin-

ity wants to send you a money-off voucher (deny and delete); your buddy is nearby and wonders if you want a coffee (accept, audio alert); the train you need to catch is delayed (accept, vibrate).

Spatial content. The challenge here is in the acquisition and access to contextual data—to understand and act appropriately on the infrastructure that is available when billions of people start to contribute MSI data every day. We will need new systems that can store, search, and mine geo-spatial data. This will require interdisciplinary and hybrid research across different fields to enable the successful collection and searching of such data in order for it to be useable, useful, and used.

Identifying the business value.

The proven feasibility and attractiveness of conceptual research scenarios like wayfinding, POI access, and exploration should now motivate the definition of more commercially oriented application concepts. In-depth user research is one of the strongest success factors to identify the real needs of specific user groups, such as tourists in a variety of mobile situations. This market-oriented research should feed into the definition of business and role models including all stakeholders of MSI: end-user communities, service providers, mobile operators, content providers, and handheld manufacturers.

We see MSI as a major opportunity to make mobile internet services useable, because interaction styles such as pointing are closely matched to situational needs of mobile users. MSI will affect both how we interact with existing information (e.g., tour-

ist attractions) and create new applications (e.g., augmented-reality games). As the technical advancements move from a research stage to production, new visualization methods and multimodal interaction concepts are needed. It is important to highlight the importance of this topic and drive joint initiatives to make MSI transition successful [ 11].

January + February 2008

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ABOUT THE AUTHORS Peter Fröhlich is a senior HCI researcher at Telecommunications Research Center Vienna (ftw.). He manages the project Point-to-Discover (p2d), which is co-funded by mobilkom austria, Siemens Austria, and the Austrian competence center kplus. The project develops the foundations for mobile spatial interaction: interaction techniques, modeling of spatial information, GIS data integration, and content aggregation, as well as hardware prototyping. Together with Lynne and Rainer, he has initiated the MSI initiative.

Lynne Baillie has a Ph.D. in HCI from Napier University in Scotland. She has worked as a senior researcher for the Telecommunication Research Center Vienna (ftw.). Since 2002 she has investigated existing HCI methods for their applicability in the mobile domain and as a result has developed new methods in order to design more usable applications for mobile devices. She has also undertaken studies in the home and investigated how we can improve and extend user-centered development methodologies to enable codesign with families.

Rainer Simon is a researcher at Telecommunications Research Center Vienna (ftw.) and a research fellow at the Vienna University of Technology Research Group for Industrial Software. He has several years of experience in the field of mobile application research and currently works with major mobile network operators on novel location-aware applications and gesture-based interaction methods for mobile phones.