A new visual interface for searching and navigating slide-based lecture videos

The rapid development of distance education technologies, e.g. MOOCs, provide learners unprecedented access to high-quality online lecture videos at scale, anytime and anywhere. Unfortunately, these valuable resources are often underutilized by online learners. One prevailing reason is the lack of support for and the resulting difficulty of exploring and locating content of interest among lengthy recordings of course lectures. To address this deficiency, we introduce a novel visual interface that supports efficient search and navigation of video content at fine granularities and with rich semantic clues. The interface is particularly designed for slide-based lecture videos (SBLV), which represent a significant portion of online lecture videos. The interface comprehensively derives versatile semantic clues for video content indexing and visual aid generation according to visual elements, text, and mathematical expressions included on lecture slides, speeches recorded, as well as mouse and cursor pointing actions captured during a lecture. Empowered by such semantically revealing indices and visual assistance, the interface is able to noticeably enhance online learners' capabilities in searching and browsing of content in need from SBLVs. The advantages of the new interface are demonstrated through benchmarked experimental results in comparison with peer methods.