The Dagstuhl-Seminar on Geographic Privacy-Aware Knowledge Discovery and Delivery was held during 16 - 21 November, 2008, with 37 participants registered from various countries from Europe, as well as other parts of the world such as United States, Canada, Argentina, and Brazil. Issues in the newly emerging area of geographic knowledge discovery with a privacy perspective were discussed in a week to consolidate some of the research questions. The Dagstuhl program included plenary sessions and special interest group meetings which continued even late in the evening with heated discussions. The plenary sessions were dedicated for the talks of some of the participants covering a variety of issues in geographic knowledge discovery and delivery. The reports on special interest group meetings (SIG) were also presented and discussed during the plenary sessions.

The topics of the talks presented during the plenary sessions could be summarized as:

• Consolidation of the notion of trajectories
• Semantic aspects of trajectories
• Warehousing of trajectories
• Mining of trajectories
• Applications
• Privacy and legal aspects

The special interest groups were formed to discuss in detail the (1) Definition and Semantics of Trajectories, (2) Applications of Anonymized Geographic Data. After each SIG meeting, a plenary meeting was organized to harmonize the results of the discussions and to share them with other interested researchers. A summary session was held for the SIG meetings to discuss open questions even basic ones regarding what a trajectory is and how do we define the specific area of knowledge discovery on geographic data, and application areas of privacy in trajectory data publication and analysis.