As more audio and video technical presentations go online, it becomes imperative to give users effective summarization and skimming tools so that they can find the presentation they want and browse through it quickly. In a previous study, we reported three automated methods for generating audio-video summaries and a user evaluation of those methods. An open question remained about how well various text/image only techniques will compare to the audio-video summarizations. This study attempts to fill that gap.

Video in digital format played on programmable devices presents opportunities for significantly enhancing the user's viewing experience. For example, time compression and pause removal can shorten the viewing time for a video, textual and visual indices can allow personalized navigation through the content, and random-access digital storage allows instantaneous seeks into the content. To understand user behavior when such capabilities are available, we built a software video browsing application that combines many such features. We present results from a user study where users browsed video in six different categories: classroom lectures, conference presentations, entertainment shows, news, sports, and travel. Our results show that the most frequently used features were time compression, pause removal, and navigation using shot boundaries. Also, the behavior was different depending on the content type, and we present a classification. Finally, the users found the browser to be very useful. Two main reasons were: i) the ability to save time and ii) the feeling of control over what content they watched.

Previous research on Tutored Video Instruction (TVI) shows that learning is enhanced when small groups of students watch and discuss lecture videos together. Using specialized, high-end videoconferencing systems, these improved results have been shown to apply even when the students are in different locations (Distributed TVI, or DTVI). In this paper, we explore two issues in making DTVI-like scenarios widely supported at low cost. First, we explore design of a system that allows distributed individuals to collectively watch video using shared VCR controls such as play, pause, seek, stop. We show how such a system can be built on top of existing commercial technologies. Second, we explore the impact of four alternative discussion channels on student learning and interaction behavior. The four channels-text chat, audioconferencing, videoconferencing, and face-to-face-have differing infrastructure requirements and costs. Our lab studies show that while text chat does not work, there is no significant difference in discussion behavior and learning between audioconferencing and videoconferencing. While lab studies have their limitations and long-term field studies need to be done, the preliminary results point to a low-cost way for a DTVI-like model to be deployed widely in the very near future.

With the proliferation of online multimedia content and the popularity of multimedia streaming systems, it is increasingly useful to be able to skim and browse multimedia quickly. A key technique that enables quick browsing of multimedia is time-compression. Prior research has described how speech can be time-compressed (shortened in duration) while preserving the pitch of the audio. However, client-server systems providing this functionality have not been available.

As streaming audio-video technology becomes widespread, there is a dramatic increase in the amount of multimedia content available on the net. Users face a new challenge: How to examine large amounts of multimedia content quickly. One technique that can enable quick overview of multimedia is video summaries; that is, a shorter version assembled by picking important segments from the original.