The retrieval module consists of the Personalizer and the user interface. The Personalizer matches indexed content from MIF with specific requests in the user profile. The user interface allows users to visualize and playback the video segments.
The Personalizer uses the user profile as a query against the stored, indexed content. The user interface represents these requests using a "magnet" metaphor, allowing users to "attract" different categories within the themes financial and celebrity. For TV financial news requests, the Personalizer searches the transcript and reconciles segment boundaries using the description given by the Bayesian Engine. When a segment has a financial category that appears more than n times (n>= 2), it is indexed under that category name. For example: if a financial news segment mentions Microsoft more than two times, that segment is indexed as "Microsoft" under the corresponding magnet. For celebrities, the Personalizer looks for matches between the summarization information produced by the Unimodal Analysis Engine and users' celebrity magnets. These matches are then stored and invoked during user interaction.
We divided the user interface into two sections called Program Guide and TV Magnets. The Program Guide allows users to interact with whole TV programs. The TV Magnets section offers users access to their profiles and access to video clips organized by topic. Users navigate the interface on a TV screen using a remote control.
The Program Guide is the first screen users see when they initiate Video Scout (Figure 45.11). Our guide differs from guides found in satellite, cable, and printed TV guides in two ways. First, we display live and stored content in a single interface. Second, we changed the orientation of the time/channel grid to support the metaphor of "raining content." This rotation also helps explain the relationship between broadcast and stored content. Live programs fall across the current time boundary—the dark line in the center—to become stored programs at the bottom. When users select a stored show they see summarized program segments separated by commercial breaks. Users can also access a more detailed view of the segmented program with longer summaries of each segment.
Figure 45.11: Program Guide screen showing a stored talk show's program segments. Each program segment has been summarized with host name and guest names.
The TV Magnets section displays video clips organized by topic. Figure 45.12 shows the Financial TV Magnet screen. As users navigate up and down the list of financial topics, stored clips matched by the Personalizer appear on the right. Figure 45.12 shows four clips that have been attracted on the topic "Dow" within three programs. Faces pulled from the video stream help to indicate the shows that clips come from. We chose to display the video clip in relation to the whole program for three reasons. First, this display is consistent with the segmentations users see in the program guide section. Second, the length of the clip in relation to the whole show offers a quick preview as to how much detail is covered in the clip. Third, topics that appear at the beginning or appear several times within a program have been given a higher priority by the broadcaster and this information may be important to users who select one clip over another.
Figure 45.12: TV Magnet showing Financial Magnet results.
The TV Magnets section also provides users with tools for refining the content that gets recorded. Users can add new topics to the list on the left. In addition, they can add filters that limit the amount of content attracted by a specific topic. For example: if users have Microsoft as a topic, they can add the term "game", limiting the content stored on Microsoft to news stories with the word game in them to obtain the latest X-Box stories.