Spatio-Temporal Proximity as a basis for Collaborative Filtering in Mobile Environments

We propose a new approach to collaborative filtering in mo- bile tourist information systems based on spatio-temporal proximity in social contexts. Users store ratings and reviews of locations and events locally within their personal information system and then exchange these with other users present in the same social contexts using ad-hoc net- working and opportunistic information sharing. We describe some pre- liminary investigations on the use of these methods in a mobile informa- tion system for visitors to a festival.