Semantic timeline interfaces for annotated multimedia assets

One of the major advantages of the Semantic Web is that resources can be annotated with arbitrary properties. It is, however, this flexibility of expression which makes it hard to develop general interface components that can be used to interact with the resources and their annotations. For many resources, however, their location is a key aspect to understand their context. The recent success of semantics maps and "virtual earth" applications proves this. Initially only used for "way finding" tasks, these tools now provide a generic access method for any type of information that has longitude/latitude information attached to it. Typical examples range from location based services (e.g. find nearby restaurants based on a current location) to "geotagged" personal images and bookmarks. We believe that a similar general access mechanism can be developed that conveys the temporal aspects of a selected set of resources to the user. Where a semantic map or satellite image allows a user to interact with the underlying data based on its location, a semantic timeline would allow interaction based on the temporal aspects of the underlying resources. Understanding, combining and reasoning with temporal information is, however, not trivial. Many schemes to deal with time have been developed. These include the use of different calendar systems, different names for the same period in disciplines such as art history and geology, the use of time points versus time intervals, qualitative versus quantitative notions of time, absolute versus relative time, etc. The proposed interface component can therefore only be realized if it has an ontological basis that describes and relates the notions of time used in the annotations and in the interface.