Establishing the Utility of Non-Text Search for News Video Retrieval with Real World Users

TRECVID participants have enjoyed consistent success using storyboard interfaces for shot-based retrieval, as measured by TRECVID interactive search mean average precision (MAP). However, much is lost by only looking at MAP, and especially by neglecting to bring in representatives of the target user communities to conduct such tasks. This paper reports on the use of within-subjects experiments to reduce subject variability and emphasize the examination of specific video search interface features for their effectiveness in interactive retrieval and user satisfaction. A series of experiments is surveyed to illustrate the gradual realization of getting non-experts to utilize non-textual query features through interface adjustments. Notably, the paper explores the use of the search system by government intelligence analysts, concluding that a variety of search methods are useful for news video retrieval and lead to improved satisfaction. This community, dominated by text search system expertise but still new to video and image search, performed better with and favored a system with image and concept query capabilities over an exclusive text-search system. The user study also found that sports topics mean nothing for this user community and tens of relevant shots collected into the answer set are considered enough to satisfy the information need. Lessons learned from these user interactions are reported, with recommendations on both interface improvements for video retrieval systems and enhancing the ecological validity of video retrieval interface evaluations