Abstract. We describe a new video interface based on a recorded personal navigation history which provides simple mechanisms to quickly find and watch previously viewed intervals, highlight segments of video the user found interesting and support other video tasks such as crowd-sourced video popularity measures and consumer-level video editing. Our novel history interface lets users find previously viewed intervals more quickly and provides a more enjoyable video navigation experience, as demonstrated by the study we performed. The user study tasked participants with viewing a pre-defined history of a subset of the video and answering questions about the video content: 83.9% of questions (average) were answered correctly using the personal navigation history, while 65.5% were answered using the state-of-art method; they took significantly less time to answer a question using our method. The full video navigation interface received an 82% average QUIS rating. The results show that our history interface can be an effective part of video players and browsers. Keywords: Video Navigation; Navigation History; Video Summarization; The dramatic increase in the quantity of video now available, either in the online form of services such as YouTube TM , Vimeo TM or the more personal form of home video, provides new challenges such as finding specific videos (or intervals within video), authoring new videos from existing content (e.g. video summarization or home movie editing), sharing video playlists (or even intervals) of online video and annotating dynamic content. The increased volume and shrinking average duration of online video has led to new use cases: users are generally free to skip ahead to find intervals which interest them; users may re-watch part of the video they enjoyed; users may employ temporal video links to provide instant access to a specific time within a video, skipping irrelevant sections; playlists and temporal links provide opportunities for customization and sharing of video consumption among users. In short, users can and want to view personally interesting intervals easily and without viewing the entire video. These use cases are supported within current interfaces, however there are no existing mechanisms to support new use cases which arise as a natural consequence, such as navigation of previously viewed intervals. Additionally, users often re-watch segments of video as part of the contemporary browsing and navigation experience [24, 25, 28] , and may wish to share these intervals with others. A historical record of video viewing would allow users to quickly find popular intervals, comment on and share them. We introduce our novel video interface, which captures the user's viewing history (analogous to a web browser history) and allows them to reuse it as a navigation tool, through a user-time visualization with supporting interactions. The history supports actions such as faster access to previously viewed intervals, visualization of popular intervals within the video based on a user's temporal view count, simpler authoring via selection of viewed intervals and provides the user with the ability to create a personalized map of the video (e.g. deciding on their own separation of the video into chapters, or highlighting interesting intervals). This type of history interface is not currently supported in commercial products, thus, we are studying interfaces for managing personal viewing history to evaluate effectiveness for inclusion in future video interfaces. Our research focuses on the utility of video history, examining use cases and establishing which are significantly affected given a user-based timeline of video viewing. The interface we designed (shown in Figure 1 ) includes a filmstrip visualization below the main video player representing the entire video, and a history to the right of the player with a sequence of intervals ordered top-down by user-time. We discovered through pilot studies that the filmstrip and history are equivalent in navigation speed to find a previously viewed event in the case where the entire video is viewed, although the history interface was preferred since users were able to customize which intervals were visualized. Our study shows that when a subset of the video is viewed, the history significantly outperforms the state-of-art, and 75% of participants preferred the history in this use case. The study found that our history-based authoring interface was useful, easy to use and enjoyable, and participants were keen to see this functionality in YouTube. We begin with a discussion of the related work, followed by a description of the video navigation interface (including all widgets and interactions used). The evaluation of the use of a history and the interfaces we designed to support it is presented, looking at users' impressions of using a personal video history and the power of using history for fast video navigation. Consider the following scenario with Robert . This scenario emphasizes the major contributions of our work: (1) a novel video navigation interface for video viewing that captures and visualizes a user's personal history; (2) an experiment that confirms using personal video navigation history is faster in finding previously seen events within videos in contrast to the state-of-art method, filmstrip; (3) a simple video mash-up tool that can be used to summarize videos by using intervals from history or simply watching the corresponding intervals, in comparison to other video editing software where users need to add a video clip, watch it, and then trim it.
However, Al-Hajri et al. REF visualized a single video history as a list of interactive segments, whereas, in this paper we are looking at multiple-videos navigation history.
Video Navigation with a Personal Viewing History
INTERACT
Computer Science