Cooperation model for video document retrieval

Information retrieval in video document archives presents specific issues. One of them is that a video document contains a large amount of information and can be seen under different aspects. We propose an information retrieval process model based on the cooperation between different specialists: specialists in the application domain, specialists of the media, and specialists in information retrieval. Each specialist has a proper point of view on documents, a partial knowledge which can be exploited in the query interpretation and during the search, and a particular role to play in the different stages of the retrieval process. A facetted data model helps to refine documents descriptions and search results. Each facet can be linked to one structure level of video documents. During the retrieval process, a flexible collaboration between several information retrieval experts is set up to deal with the different aspects of documents and query descriptions and to improve retrieval performance. A prototype, using the MHEG standard, is being implemented to retrieve TV news sequences and to present search results in a hypermedia form.