This workshop has been organized as a successor to five preceding ones that were centered around topics of computational cartography and geographic information systems. The major goal has been to bring together the still small, but fast growing, research community that is involved in developing better computational techniques for spatio-temporal object representation, data mining, and visualization massive amounts of moving object data. The participants included experts from fields such as computational geometry, spatial databases, GIScience, photogrammetry, spatial statistics, and knowledge discovery and data mining. The majority of participants where from academic institutions, some from government agencies. Several industry representatives were invited, but unfortunately were unable to attend the seminar. However, one of the organizers is from ESRI Inc., the leading GIS company. The seminar has lead to a fruitful exchange of ideas between different disciplines, to the creation of new collaborations, and to recommendations for future research directions.

Mobility is key in a globalized world where people, goods, data and even ideas move in increasing volumes at increasing speeds over increasing distances. Understanding of mobility patterns and movement behaviors will increasingly become a key factor for success in many businesses such as location-based services (LBS), advertising, and logistics. It will be essential for the prediction and monitoring of individual and group behaviors in response to and mitigation of security threats over short and long time scales. Traffic simulation can greatly benefit from the analysis of movement data, for example through better estimates of key parameters. Finally, mobility patterns of endangered species are prerequisites to devising protective measures in nature conservation and successfully managing interactions between tourism and conservation.

Dynamic geographic objects may include phenomena as diverse as people, animals, vehicles or hurricanes, or the pathways of diseases such as SARS. Data recording the trajectories of MOs stem from a variety of sources, ranging from radio telemetry and GPS to mobile telecommunication devices and geo-sensor networks. Despite the diversity of sources and moving objects involved, movement data have in common that they represent joint recordings of spatial and temporal dimensions and capture motion in trajectories. Hence, it is possible to develop powerful methods for knowledge discovery (KD), by data mining and visual analytics, in movement data that can be suited to the needs of diverse application domains. KD of movement patterns may be performed in real-time (e.g. in geo-sensor networks) or off-line and a posteriori. Furthermore, the purpose may be explanation - e.g., discovering and explaining behavioral patterns of an animal to devise better protection measures. Or it may be prediction - e.g., predicting the next move of an object to trigger personalized information feeds in a mobile information system or issue a warning.

The problem is that we are only at the beginning of the evolution of a new research domain. Hence, despite the collection of increasing amounts of data in recent years which can be used in movement tracking, only few methods exist today which have been demonstrated to effectively exploit very large volumes of movement data at different spatial and temporal scales. Recent years have however seen increased interest in the development of such methods, which are currently being developed in a rather piecemeal fashion, and have yet to migrate from research to demonstrate convincing social and commercial benefits.

Outcomes of the seminar include a collection of abstracts, presentations (slides) and some papers surveying the current state of the art in this field and latest research initiatives (available on the website http://www.dagstuhl.de/08451/Materials/). Similar to the previous seminars of this series, it is expected that new partnerships and collaborations between multi-disciplinary groups will form, further advancing this field with the inclusion of emerging topics. As a first concrete initiative in this direction, a proposal for a European COST Action on "Knowledge Discovery from Moving Objects” was launched (http://www.cost.esf.org). The preliminary proposal has since been accepted and the full proposal will be submitted in January 2009. The Dagstuhl seminar provided plenty of useful inputs for the full proposal, as well as links to researchers who are interested to participate in the proposed COST Action. Most of the Europeans among the participants of Dagstuhl seminar 08451 will also participate in the COST Action.

Another important result of the seminar is the list of past and future research directions that was compiled during the final round of breakout discussions on the last day of the seminar.