Much of hypertext narrative relies on links to shape a reader's interaction with the text. But links may be too limited to express ambiguity, imprecision, and entropy, or to admit new modes of participation short of full collaboration. We use an e-book form to explore the implications of freeform annotation-based interaction with hypertext narrative. Readers' marks on the text can be used to guide navigation, create a persistent record of a reading, or to recombine textual elements as a means of creating a new narrative. In this paper, we describe how such an experimental capability was created on top of XLibris, a next generation e-book, using Forward Anywhere as the hypernarrative. We work through a scenario of interaction, and discuss the issues the work raises

We present and interactive system that allows a user to locate regions of video that are similar to a video query. Thus segments of video can be found by simply providing an example of the video of interest. The user selects a video segment for the query from either a static frame-based interface or a video player. A statistical model of the query is calculated on-the-fly, and is used to find similar regions of video. The similarity measure is based on a Gaussian model of reduced frame image transform coefficients. Similarity in a single video is displayed in the Metadata Media Player. The player can be used to navigate through the video by jumping between regions of similarity. Similarity can be rapidly calculated for multiple video files as well. These results are displayed in MBase, a Web-based video browser that allows similarity in multiple video files to be visualized simultaneously.

This paper describes an application-independent tool called Anchored Conversations that brings together text-based conversations and documents. The design of Anchored Conversations is based on our observations of the use of documents and text chats in collaborative settings. We observed that chat spaces support work conversations, but they do not allow the close integration of conversations with work documents that can be seen when people are working together face-to-face. Anchored Conversations directly addresses this problem by allowing text chats to be anchored into documents. Anchored Conversations also facilitates document sharing; accepting an invitation to an anchored conversation results in the document being automatically uploaded. In addition, Anchored Conversations provides support for review, catch-up and asynchronous communications through a database. In this paper we describe motivating fieldwork, the design of Anchored Conversations, a scenario of use, and some preliminary results from a user study.

This paper presents a method for generating compact pictorial summarizations of video. We developed a novel approach for selecting still images from a video suitable for summarizing the video and for providing entry points into it. Images are laid out in a compact, visually pleasing display reminiscent of a comic book or Japanese manga. Users can explore the video by interacting with the presented summary. Links from each keyframe start video playback and/or present additional detail. Captions can be added to presentation frames to include commentary or descriptions such as the minutes of a recorded meeting. We conducted a study to compare variants of our summarization technique. The study participants judged the manga summary to be significantly better than the other two conditions with respect to their suitability for summaries and navigation, and their visual appeal.

S. Ichimura, L. Nelson, E.R. Pedersen.

Recently, physicists and computer scientists have realized that not only do our ideas about computing rest on only partly accurate principles, but they miss out on a whole class of computation. Quantum physics offers powerful methods of encoding and manipulating information that are not possible within a classical framework. The potential applications of these quantum information processing methods include provably secure key distribution for cryptography, rapid integer factoring, and quantum simulation.

J. Cassell, J. Sullivan, S. Prevost, and E. Churchill (Eds.).

The development of tools to support synchronous communications between non-collocated colleagues has received considerable attention in recent years. Much of the work has focused on increasing a sense of co-presence between interlocutors by supporting aspects of face-to-face conversations that go beyond mere words (e.g. gaze, postural shifts). In this regard, a design goal for many environments is the provision of as much media-richness as possible to support non-collocated communication. In this paper we present results from our most recent interviews studying the use of a text-based virtual environment to support work collaborations. We describe how such an environment, though lacking almost all the visual and auditory cues known to be important in face-to-face conversation, has played an important role in day-to-day communication. We offer a set of characteristics we feel are important to the success of this text-only tool and discuss issues emerging from its long-term use.

NoteLook is a client-server system designed and built to support multimedia note taking in meetings with digital video and ink. It is integrated into a conference room equipped with computer controllable video cameras, video conference camera, and a large display rear video projector. The NoteLook client application runs on wireless pen-based notebook computers. Video channels containing images of the room activity and presentation material are transmitted by the NoteLook servers to the clients, and the images can be interactively and automatically incorporated into the note pages. Users can select channels, snap in large background images and sequences of thumbnails, and write freeform ink notes. A smart video source management component enables the capture of high quality images of the presentation material from a variety of sources. For accessing and browsing the notes and recorded video, NoteLook generates Web pages with links from the images and ink strokes correlated to the video.

This paper presents methods for automatically creating pictorial video summaries that resemble comic books. The relative importance of video segments is computed from their length and novelty. Image and audio analysis is used to automatically detect and emphasize meaningful events. Based on this importance measure, we choose relevant keyframes. Selected keyframes are sized by importance, and then efficiently packed into a pictorial summary. We present a quantitative measure of how well a summary captures the salient events in a video, and show how it can be used to improve our summaries. The result is a compact and visually pleasing summary that captures semantically important events, and is suitable for printing or Web access. Such a summary can be further enhanced by including text captions derived from OCR or other methods. We describe how the automatically generated summaries are used to simplify access to a large collection of videos.

This paper presents a novel approach to visualizing the time structure of music and audio. The acoustic similarity between any two instants of an audio recording is calculated and displayed as a two-dimensional representation. Similar or repeating elements are visually distinct, allowing identification of structural and rhythmic characteristics. Visualization examples are presented for orchestral, jazz, and popular music. Applications include content-based analysis and segmentation, as well as tempo and structure extraction.

We present efficient implementations of a number of operations for quantum computers. These include controlled phase adjustments of the amplitudes in a superposition, permutations, approximations of transformations and generalizations of the phase adjustments to block matrix transformations. These operations generalize those used in proposed quantum search algorithms.

We describe a media enriched conference room designed for capturing meetings. Our goal is to do this in a flexible, seamless, and unobtrusive manner in a public conference room that is used for everyday work. Room activity is captured by computer controllable video cameras, video conference cameras, and ceiling microphones. Presentation material displayed on a large screen rear video projector is captured by a smart video source management component that automatically locates the highest fidelity image source. Wireless pen-based notebook computers are used to take notes, which provide indexes to the captured meeting. Images can be interactively and automatically incorporated into the notes. Captured meetings may be browsed on the Web with links to recorded video.

In our Portholes research, we found that users needed to have a sense of being in public and to know who can see them (audience) and who is looking currently at them (lookback). Two redesigns of the Portholes display present a 3D theater view of the audience. Different sections display core team members, non-core team members and lookback. An experiment determined that people have strong preferences about audience information and how it should be displayed. Layout preferences are varied, but unfolding techniques and cluster analysis reveal that these preference perspectives fall into four groups of similar preferences.

When reviewing collections of video such as recorded meetings or presentations, users are often interested only in an overview or short segments of these documents. We present techniques that use automatic feature analysis, such as slide detection and applause detection, to help locate the desired video and to navigate to regions of interest within it. We built a web-based interface that graphically presents information about the contents of each video in a collection such as its keyframes and the distribution of a particular feature over time. A media player is tightly integrated with the web interface. It supports navigation within a selected file by visualiz-ing confidence scores for the presence of features and by using them as index points. We conducted a user study to refine the usability of these tools.

User interfaces for digital libraries tend to focus on retrieval: users retrieve documents online, but then print them out and work with them on paper. One reason for printing documents is to annotate them with freeform ink while reading. Annotation can help readers to understand documents and to make them their own. In addition, annotation can reveal readers' interests with respect to a particular document. In particular, it is possible to construct full-text queries based on annotated passages of documents. We describe an experiment that tested the effectiveness of such queries, as compared to relevance feedback query techniques. For a set of TREC topics and documents, queries derived from annotated passages produced significantly better results than queries derived from subjects' judgments of relevance.

How will we read digital library materials? This paper describes the reading practices of an on-going reading group, and how these practices changed when we introduced XLibris, a digital library reading appliance that uses a pen tablet computer to provide a paper-like interface. We interviewed group members about their reading practices, observed their meetings, and analyzed their annotations, both when they read a paper document and when they read using XLibris. We use these data to characterize their analytic reading, reference use, and annotation practices. We also describe the use of the Reader's Notebook, a list of clippings that XLibris computes from a reader's annotations. Implications for digital libraries stem from our findings on reading and mobility, the complexity of analytic reading, the social nature of reference following, and the unselfconscious nature of readers' annotations.

The Palette is a digital appliance designed for intuitive control of electronic slide shows. Current interfaces demand too much of our attention to permit effective computer use in situations where we can not give the technology our fullest concentration. The Palette uses index cards that are printed with slide content that is easily identified by both humans and computers. The presenter controls the presentation by directly manipulating the cards. The Palette design is based on our observation of presentations given in a real work setting. Our experiences using the system are described, including new practices (e.g., collaborative presentation, enhanced notetaking) that arise from the affordances of this new approach. This system is an example of a new interaction paradigm called tacit interaction that supports users who can spare very little attention to a computer interface.