Investigations on Event Evolution in TDT

Topic detection and tracking approaches monitor broadcast news in order to spot new, previously unreported events and to track the development of the previously spotted ones. The dynamical nature of the events makes the use of state-of-the-art methods difficult. We present a new topic definition that has potential to model evolving events. We also discuss incorporating ontologies into the similarity measures of the topics, and illustrate a dynamic hierarchy that decreases the exhaustive computation performed in the TDT process. This is mainly work-in-progress