Abstract: We propose a navigation technique for browsing large documents that integrates rate-based scrolling with automatic zooming. The view automatically zooms out when the user scrolls rapidly so that the perceptual scrolling speed in screen space remains constant. As a result, the user can efficiently and smoothly navigate through a large document without becoming disoriented by extremely fast visual flow. By incorporating semantic zooming techniques, the user can smoothly access a global overview of the document during rate-based scrolling. We implemented several prototype systems, including a web browser, map viewer, image browser, and dictionary viewer. An informal usability study suggests that for a document browsing task, most subjects prefer automatic zooming and the technique exhibits approximately equal performance time to scroll bars , suggesting that automatic zooming is a helpful alternative to traditional scrolling when the zoomed out view provides appropriate visual cues.

Abstract: Speech-based user interfaces are growing in popularity. Unfortunately, the technology expertise required to build speech UIs precludes many individuals from participating in the speech interface design process. Furthermore, the time and knowledge costs of building even simple speech systems make it difficult for designers to iteratively design speech UIs. SUEDE, the speech interface prototyping tool we describe in this paper, allows designers to rapidly create prompt/response speech interfaces. It offers an electronically supported Wizard of Oz (WOz) technique that captures test data, allowing designers to analyze the interface after testing. This informal tool enables speech user interface designers, even non-experts, to quickly create, test, and analyze speech user interface prototypes.

Abstract: We introduce “fisheye menus” which apply traditional fisheye graphical visualization techniques to linear menus. This provides for an efficient mechanism to select items from long menus, which are becoming more common as menus are used to select data items in, for example, ecommerce applications. Fisheye menus dynamically change the size of menu items to provide a focus area around the mouse pointer. This makes it possible to present the entire menu on a single screen without requiring buttons, scrollbars, or hierarchies. A pilot study with 10 users compared user preference of fisheye menus with traditional pull-down menus that use scrolling arrows, scrollbars, and hierarchies. Users preferred the fisheye menus for browsing tasks, and hierarchical menus for goal-directed tasks.

Abstract: The ToolStone is a cordless, multiple degree-of-freedom (MDOF) input device that senses physical manipulation of itself, such as rotating, flipping, or tilting. As an input device for the non-dominant hand when a bimanual interface is used, the ToolStone provides several interaction techniques including a toolpalette selector, and MDOF interactors such as zooming, 3D rotation, and virtual camera control. In this paper, we discuss the design principles of input devices that effectively use a human’s physical manipulation skills, and describe the system architecture and applications of the ToolStone input device.

Abstract: The XWeb project addresses the problem of interacting with services by means of a variety of interactive platforms. Interactive clients are provided on a variety of hardware/software platforms that can access and XWeb service. Creators of services need not be concerned with interactive techniques or devices. The cross platform problems of a network model of interaction, adaptation to screen size and supporting both speech and visual interfaces in the same model are addressed.

Abstract: Because of its promise of natural interaction, recognition is coming into its own as a mainstream technology for use with computers. Both commercial and research applications are beginning to use it extensively. However the errors made by recognizers can be quite costly, and this is increasingly becoming a focus for researchers. We present a survey of existing error correction techniques in the user interface. These mediation techniques most commonly fall into one of two strategies, repetition and choice. Based on the needs uncovered by this survey, we have developed OOPS, a toolkit that supports resolution of input ambiguity through mediation. This paper describes four new interaction techniques built using OOPS, and the toolkit mechanisms required to build them. These interaction techniques each address problems not directly handled by standard approaches to mediation, and can all be re-used in a variety of settings.

Abstract: A new interaction technique called Dual Touch has been developed for pen-based PDAs. It enables a user to operate a PDA by tapping and stroking on the screen with a pen and a thumb. The PDA can detect the combined movements of two points on its pressure-based touchscreen without additional hardware. The user can use the thumb to support the task of the pen.

Abstract: TopicShop is an interface that helps users evaluate and organize collections of web sites. The main interface components are site profiles, which contain information that helps users select high-quality items, and a work area, which offers thumbnail images, annotation, and lightweight grouping techniques to help users organize selected sites. The two components are linked to allow task integration. Previous work [2] demonstrated that subjects who used TopicShop were able to select significantly more highquality sites, in less time and with less effort. We report here on studies that confirm and extend these results. We also show that TopicShop subjects spent just half the time organizing sites, yet still created more groups and more annotations, and agreed more in how they grouped sites. Finally, TopicShop subjects tightly integrated the tasks of evaluating and organizing sites. INTRODUCTION In previous work [2], we motivated an important task for web users – gathering, evaluating, and organizing information resources for a given topic. Current web tools do not support this task well; specifically, they do not make it easy to evaluate collections of web sites to select the best ones or to organize sites for future reuse and sharing. Users have to browse and view sites one after another until they are satisfied they have a good set, or, more likely, they get tired and give up. Browsing a web site is an expensive operation, both in time and cognitive effort. And bookmarks, the most common form of keeping track of web sites, are a fairly primitive organizational technique. We designed and implemented the TopicShop system to provide comprehensive, integrated support for this task. TopicShop aids users in finding a set of relevant sites, in narrowing down the set into a smaller set of high quality sites, and in organizing sites for future use. TopicShop has evolved through a number of design iterations, driven by extensive user testing. We report here on lessons we learned from a pilot study, how these lessons re-shaped our understanding of the task and led to a significant re-design, and the results of a second, larger user study. RELATED WORK Our research program investigates the major information problems faced by users of the World Wide Web: • finding collections of items relevant to their interests; • identifying high-quality items within a collection; • finding items that contain a certain category of information, e.g., episode guides (for a television show) or song lyrics (for a musician); • organizing personalized subsets of items. We have addressed these problems by developing algorithms, implementing them in web crawling and analysis tools, creating interfaces to support users in exploring, comprehending, and organizing collections of web documents, and performing user studies [2, 3, 4, 15]. The work reported here focuses on understanding the user tasks of evaluating and organizing collections of web sites, as illuminated by the design, evaluation, and re-design of interfaces to support these tasks. Other researchers have investigated these issues. Much recent work has been devoted to algorithms for adding meta-information to collections of web sites to enhance user comprehension, typically by analyzing the structure of links between sites. This approach builds on the intuition that when the author of one site chooses to link to another, this often implies both that the sites have similar content and that the author is endorsing the content of the linked-to site. Pirolli, Pitkow and colleagues [12, 13] experimented with link-based algorithms for clustering and categorizing web pages. Kleinberg’s HITS algorithm [8] defines authoritative and hub pages within a hypertext collection. Authorities and hubs are mutually dependent: a good authority is a page that is linked to by many hubs, and a good hub is one that links to many authorities. After evaluating items and selecting the interesting ones, users must organize the items for future use. Card, Robertson, and Mackinlay [5] introduced the concept of information workspaces to refer to environments in which information items can be stored and manipulated. A departure point for most such systems is the file manager popularized by the Apple Macintosh and then in Microsoft Windows. Such systems typically include a list view, which shows various properties of items, and an icon view, Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. UIST ’00. San Diego, CA USA  2000 ACM 1-58113-212-3/00/11... $5.00 CHI Letters vol 2, 2 201 which lets users organize icons representing the items in a 2D space. Mander, Salomon, and Wong [10] enhanced the basic metaphor with the addition of “piles”. Users could create and manipulate piles of items. Interesting interaction techniques for displaying, browsing, and searching piles were designed and tested. Bookmarks are the most popular way to create personal information workspaces of web resources. Bookmarks consist of lists of URLs; typically the title of the web page is used as the label for the URL. Users may organize their bookmarks into a hierarchical category structure. Abrams, Baecker, and Chignell [1] carried out an extensive study of how several hundred web users used bookmarks. They observed a number of strategies for organizing bookmarks, including a flat ordered list, a single level of folders, and hierarchical folders. They also made four design recommendations to help users manage their bookmarks more effectively. First, bookmarks must be easy to organize, e.g., via automatic sorting techniques. Second, visualization techniques are necessary to provide comprehensive overviews of large sets of bookmarks. Third, rich representations of sites are required; many users noted that site titles are not accurate descriptors of site content. Finally, tools for managing bookmarks must be well integrated with web browsers. Many researchers have created experimental information workspace interfaces, often designed expressly for web documents. Card, Robertson, and York [5] describe the WebBook, which uses a book metaphor to group a collection of related web pages for viewing and interaction, and the WebForager, an interface that lets users view and manage multiple WebBooks. Mackinlay, Rao, and Card [9] developed a novel user interface for accessing articles from a citation database. The central UI object is a “Butterfly”, which represents an article, its references, and its citers. The interface makes it easy for users to browse among related articles, group articles, and generate queries to retrieve articles that stand in a particular relationship to the current article. The Data Mountain of Robertson et al [14] represents documents as thumbnail images in a 3D virtual space. Users can move and group the images freely, with various interesting visual and audio cues used to help users arrange the documents. In a study comparing the use of Data Mountain to Internet Explorer Favorites, Data Mountain users retrieved items more quickly, with fewer incorrect or failed retrievals. Our research shares goals with much of the previous work. We focus on designing interfaces that make automatically extracted information about web sites readily accessible to users. We show that this increases users’ ability to select high-quality sites. Through ongoing user studies and redesign, we developed easy-to-use annotation and grouping techniques that let users organize items better and more quickly. Finally, we learned how users interleave work on various tasks and re-designed our interface to support such task interleaving. TOPICSHOPEXPLORER, VERSION 1 The TopicShop Explorer is implemented in C++ and runs on Microsoft Windows platforms. Version 1 was based directly on the Macintosh file manager / MS Windows Explorer metaphor (see [3] for detail of TopicShop Version 1 and the pilot study). Accordingly, users could view collections in either a details (Figure 1) or icons (Figure 2) view. The details view showed site profile information (see below) to help users evaluate sites, and the icons view let users organize sites spatially. Figure 1: TopicShop Explorer (version 1), details view. Each web site is represented by a small thumbnail image, the site title, and profile data including the links to/from other sites in the collection, and the number of pages, images, and audio files on the site. Users can sort by a property by clicking on the appropriate column. Figure 2: TopicShop Explorer (version 1), icons view. Each site is represented by a large thumbnail image and the site title. Users can organize sites by arranging them spatially, a technique especially useful in the early stages of exploration. The collections of sites and site profile data used in TopicShop are obtained by running a webcrawler/analyzer. The crawler takes a user-specified set of seed sites as input, and follows links from the seeds to construct a graph of the seed sites, pages contained on these sites, and, optionally, sites determined to be related based on their textual and hyperlink connections to the seeds. CHI Letters vol 2, 2 202 Site profiles are built by fetching a large number of pages from each site. Profiles contain content data, including the page title, an estimate of the page count, and a roster of audio files, movie files, and images; they also record links between sites in the collection. In addition, a thumbnail image of each site’s root page is constructed. The first goal of TopicShop is to help users evaluate and identify high quality sites. We sought to achieve this goal by providing site profile data and int

Abstract: We describe a simple technique for accurately calibrating the temporal lag in augmented and virtual environments within the Enhanced Virtual Hand Lab (EVHL), a collection of hardware and software to support research on goal-directed human hand motion. Lag is the sum of various delays in the data pipeline associated with sensing, processing, and displaying information from the physical world to produce an augmented or virtual world. Our main calibration technique uses a modified phonograph turntable to provide easily tracked periodic motion, reminiscent of the pendulum-based calibration technique of Liang, Shaw and Green. Measurements show a three-frame (50 ms) lag for the EVHL. A second technique, which uses a specialized analog sensor that is part of the EVHL, provides a “closed loop” calibration capable of sub-frame accuracy. Knowing the lag to sub-frame accuracy enables a predictive tracking scheme to compensate for the end-toend lag in the data pipeline. We describe both techniques and the EVHL environment in which they are used.

Abstract: We have implemented a computer interface that renders synchronized auditory and haptic stimuli with very low (0.5ms) latency. The audio and haptic interface (AHI) includes a Pantograph haptic device that reads position input from a user and renders force output based on this input. We synthesize audio by convolving the force profile generated by user interaction with the impulse response of the virtual surface. Auditory and haptic modes are tightly coupled because we produce both stimuli from the same force profile. We have conducted a user study with the AHI to verify that the 0.5ms system latency lies below the perceptual threshold for detecting separation between auditory and haptic contact events. We discuss future applications of the AHI for further perceptual studies and for synthesizing continuous contact interactions in virtual environments.

Abstract: Traditionally, designers organize software system as active end-points (e.g. applications) linked by passive infrastructures (e.g. networks). Increasingly, however, networks and infrastructures are becoming active components that contribute directly to application behavior. Amongst the various problems that this presents is the question of how such active infrastructures should be programmed. We have been developing an active document management system called Placeless Documents. Its programming model is organized in terms of properties that actively contribute to the functionality and behavior of the documents to which they are attached. This paper discusses active properties and their use as a programming model for active infrastructures. We have found that active properties enable the creation of persistent, autonomous active entities in document systems, independent of specific repositories and applications, but present challenges for managing problems of composition.

Abstract: We describe a robust working prototype of a system for accurate page-ID detection from bound paper books. Our method uses a new RFID technology to recognize book page location. A thin flexible transponder tag with a unique ID is embedded in the paper of each page, and a tag reader is affixed to the binding of the back of the book. As the pages turn, the tag reader notices which tags are within its read range and which have moved out of its range (which is about four inches). The human interacts with the book naturally, and is not required to perform any actions for page detection that are not usual in book interaction. The page-detection data can be used to enhance the experience of the book, or to enable the book as a controller for another system. One such system, an interactive museum exhibit, is briefly described.

Abstract: User interface components such as buttons, scrollbars, menus, as well as various types of containers and separators, normally need to be resizable so that they can conform to the needs of the contents within them, or the environment in which they are placed. Unfortunately, in the past, providing dynamically resizable component appearances has required writing code to draw the component. As a result, visual designers have often been cut off from the ability to create these appearances. Even when visual designers can be involved, drawing programmatically is comparatively very difficult. Hence, components created this way have not typically contained artistically rich appearances. Because of this need to write drawing code, component appearances have traditionally been quite plain, and have been controlled primarily by a few toolkit writers. This paper presents a suite of very simple techniques, along with a few composition mechanisms, that are designed to overcome this problem. These techniques allow visually rich, dynamically resizable, images to be provided using primarily conventional drawing tools (and with no programming or programming-like activities at all).

Abstract: Sensory feedback for user actions in arbitrarily large information worlds can exhaust the limited dynamic range of human sensation. Two well-known illusions, one optical and one auditory, can be used to give arbitrarily large ranges of feedback.

Abstract: Existing devices for communicating information to computers are bulky, slow to use, or unreliable. Dasher is a new interface incorporating language modelling and driven by continuous two-dimensional gestures, e.g. a mouse, touchscreen, or eye-tracker. Tests have shown that this device can be used to enter text at a rate of up to 34 words per minute, compared with typical ten-finger keyboard typing of 40-60 words per minute. Although the interface is slower than a conventional keyboard, it is small and simple, and could be used on personal data assistants and by motion-impaired computer users.

Abstract: One major goal of multimodal system design is to support more robust performance than can be achieved with a unimodal recognition technology, such as a spoken language system. In recent years, the multimodal literatures on speech and pen input and speech and lip movements have begun developing relevant performance criteria and demonstrating a reliability advantage for multimodal architectures. In the present studies, over 2,600 utterances processed by a multimodal pen/voice system were collected during both mobile and stationary use. A new data collection infrastructure was developed, including instrumentation worn by the user while roaming, a researcher field station, and a multimodal data logger and analysis tool tailored for mobile research. Although speech recognition as a stand-alone failed more often during mobile system use, the results confirmed that a more stable multimodal architecture decreased this error rate by 1935%. Furthermore, these findings were replicated across different types of microphone technology. In large part this performance gain was due to significant levels of mutual disambiguation in the multimodal architecture, with higher levels occurring in the noisy mobile environment. Implications of these findings are discussed for expanding computing to support more challenging usage contexts in a robust manner.

Abstract: We have developed a system for remedial reading instruction that uses visually controlled auditory prompting to help the user with recognition and pronunciation of words. Our underlying hypothesis is that the relatively unobtrusive assistance rendered by such a system will be more effective than previous computer aided approaches. We present a description of the design and implementation of our system and discuss a controlled study that we undertook to evaluate the usability of the Reading Assistant.

Abstract: Hitchcock is a system that allows users to easily create custom videos from raw video shot with a standard video camera. In contrast to other video editing systems, Hitchcock uses automatic analysis to determine the suitability of portions of the raw video. Unsuitable video typically has fast or erratic camera motion. Hitchcock first analyzes video to identify the type and amount of camera motion: fast pan, slow zoom, etc. Based on this analysis, a numerical " unsuit-ability " score is computed for each frame of the video. Combined with standard editing rules, this score is used to identify clips for inclusion in the final video and to select their start and end points. To create a custom video, the user drags keyframes corresponding to the desired clips into a storyboard. Users can lengthen or shorten the clip without specifying the start and end frames explicitly. Clip lengths are balanced automatically using a spring-based algorithm.

Abstract: : In this paper the authors investigate the use of scene graphs as a general approach for implementing two-dimensional (2D) graphical applications, and in particular Zoomable User Interfaces (ZUIs) Scene graphs are typically found in three-dimensional (3D) graphics packages such as Sun's Java3D and SGI's OpenInventor They have not been widely adopted by 2D graphical user interface toolkits To explore the effectiveness of scene graph techniques, the authors have developed Jazz, a general-purpose 2D scene graph toolkit Jazz is implemented in Java using Java2D, and runs on all platforms that support Java 2 This paper describes Jazz and the lessons we learned using Jazz for ZUIs It also discusses how 2D scene graphs can be applied to other application areas (5 figures, 27 refs)

Abstract: We describe sensing techniques motivated by unique aspects of human-computer interaction with handheld devices in mobile settings. Special features of mobile interaction include changing orientation and position, changing venues, the use of computing as auxiliary to ongoing, real-world activities like talking to a colleague, and the general intimacy of use for such devices. We introduce and integrate a set of sensors into a handheld device, and demonstrate several new functionalities engendered by the sensors, such as recording memos when the device is held like a cell phone, switching between portrait and landscape display modes by holding the device in the desired orientation, automatically powering up the device when the user picks it up the device to start using it, and scrolling the display using tilt. We present an informal experiment, initial usability testing results, and user reactions to these techniques.

Abstract: We present a new kind of marking menu that was developed for use with a pen device on display surfaces such as large, high resolution, wall-mounted displays. It integrates capabilities of previously separate mechanisms such as marking menus and Quikwriting, and facilitates the entry of multiple commands. While using this menu, the pen never has to leave the active surface so that consecutive menu selections, data entry (text and parameters) and direct manipulation tasks can be integrated fluidly.

Abstract: We describe a new sketching interface in which shape recognition and morphing are tightly coupled. Raw input strokes are continuously morphed into ideal geometric shapes, even before the pen is lifted. By means of smooth and continual shape transformations the user is apprised of recognition progress and the appearance of the final shape, yet always retains a sense of control over the process. At each time t the system uses the trajectory traced out thus far by the pen coupled with the current appearance of the time-varying shape to classify the sketch as one of several pre-defined basic shapes. The recognition operation is performed using shape-specific fits based on least-squares or relaxation, which are continuously updated as the user draws. We describe the time-dependent transformation of the sketch, beginning with the raw pen trajectory, using a family of first-order ordinary differential equations that depend on time and the current shape of the sketch. Using this formalism, we describe several possible behaviors that result by varying the relative significance of new and old portions of a stroke, changing the “viscosity” of the morph, and enforcing different end conditions. A preliminary user study suggests that the new interface is particularly effective for rapidly constructing diagrams consisting of simple shapes.

Abstract: All of these systems rely on an explicit model of history, which can be scanned to support search or “navigation” over a timeline, and all allow their timelines to be “traversed” to move the application’s state to other points in its history. However, as powerful as these applications are, their timeline representations are for the most part exceedingly simple. They typically support only linear, not branching timelines (GINA and Timewarp are exceptions, however); the “nodes” in a timeline must represent atomic operations with side effects that are well understood at the time the application is created; and, typically, the timeline of the entire application must be navigated or traversed as a whole—it is impossible to have a portion of the timeline exist in a “bubble” that can be manipulated separately.

Abstract: We present a general approach to the dynamic representation of 2D space that is well suited for userinterface layout. We partition space into two distinct categories: full and empty. The user can explicitly specify a set of possibly overlapping upright rectangles that represent the objects of interest. These full-space rectangles are processed by the system to create a representation of the remaining empty space. This representation makes it easy for users to develop customized spatial allocation strategies that avoid overlapping the full-space rectangles. We describe the representation; provide efficient incremental algorithms for adding and deleting full-space rectangles, and for querying the empty-space representation; and show several allocation strategies that the representation makes possible. We present two testbed applications that incorporate an implementation of the algorithm; one shows the utility of our representation for window management tasks; the other applies it to the layout of components in a 3D user interface, based on the upright 2D bounding boxes of their projections.

Abstract: We have developed an interface for editing and simulating Coloured Petri Nets based on toolglasses, marking menus and bi-manual interaction, in order to understand how novel interaction techniques could be supported by a new generation of user interface toolkits. The architecture of CPN2000 is based on three components: the Document Structure stores all the persistent data in the system; the Display Structure represents the contents of the screen and implements rendering and hit detection algorithms; and the Input Structure uses "instruments" to manage interaction. The rendering engine is based on OpenGL and a number of techniques have been developed to take advantage of 3D accelerated graphics for a 2D application. Performance data show that high frame rates have been achieved with off-theshelf hardware even with a non-optimized redisplay. This work paves the way towards a post-WIMP UI toolkit.

Abstract: Software support for making effective pen-based applications is currently rudimentary. To facilitate the creation of such applications, we have developed SATIN, a Java-based toolkit designed to support the creation of applications that leverage the informal nature of pens. This support includes a scenegraph for manipulating and rendering objects; support for zooming and rotating objects, switching between multiple views of an object, integration of pen input with interpreters, libraries for manipulating ink strokes, widgets optimized for pens, and compatibility with Java's Swing toolkit. SATIN includes a generalized architecture for handling pen input, consisting of recognizers, interpreters, and multi-interpreters. In this paper, we describe the functionality and architecture of SATIN, using two applications built with SATIN as examples.

Abstract: In this paper, we discuss a re-configurable pipeline architecture that is ideally suited for applications in which a user is interactively managing a stream of data. Currently, document service buses allow stand-alone document services (translation, printing, etc.) to be combined for batch processing. Our architecture allows services to be composed and re-configured on the fly in order to support interactive applications. To motivate the need for such an architecture we address the problem of finding and organizing images on the World Wide Web. The resulting tool, PicturePiper, provides a mechanism for allowing users access to images on the web related to a topic of interest.