Although information visualization (infovis) technologies have proven indispensable tools for making sense of complex data, wide-spread deployment has yet to take hold, as successful infovis applications are often difficult to author and require domain-specific customization. To address these issues, we have created prefuse, a software framework for creating dynamic visualizations of both structured and unstructured data. prefuse provides theoretically-motivated abstractions for the design of a wide range of visualization applications, enabling programmers to string together desired components quickly to create and customize working visualizations. To evaluate prefuse we have built both existing and novel visualizations testing the toolkit's flexibility and performance, and have run usability studies and usage surveys finding that programmers find the toolkit usable and effective.

In this paper, we analyze toolkit designs for building graphical applications with rich user interfaces, comparing polylithic and monolithic toolkit-based solutions. Polylithic toolkits encourage extension by composition and follow a design philosophy similar to 3D scene graphs supported by toolkits including Java3D and OpenInventor. Monolithic toolkits, on the other hand, encourage extension by inheritance, and are more akin to 2D Graphical User Interface toolkits such as Swing or MFC. We describe Jazz (a polylithic toolkit) and Piccolo (a monolithic toolkit), each of which we built to support interactive 2D structured graphics applications in general, and Zoomable User Interface applications in particular. We examine the trade offs of each approach in terms of performance, memory requirements, and programmability. We conclude that a polylithic approach is most suitable for toolkit builders, visual design software where code is automatically generated, and application builders where there is much customization of the toolkit.

We present a novel tree browser that builds on the conventional node link tree diagrams. It adds dynamic rescaling of branches of the tree to best fit the available screen space, optimized camera movement, and the use of preview icons summarizing the topology of the branches that cannot be expanded. In addition, it includes integrated search and filter functions. This paper reflects on the evolution of the design and highlights the principles that emerged from it. A controlled experiment showed benefits for navigation to already previously visited nodes and estimation of overall tree topology.

The literature on information visualization establishes the usability of interfaces with an overview of the information space, but for zoomable user interfaces, results are mixed. We compare zoomable user interfaces with and without an overview to understand the navigation patterns and usability of these interfaces. Thirty-two subjects solved navigation and browsing tasks on two maps. We found no difference between interfaces in subjects ’ ability to solve tasks correctly. Eighty percent of the subjects preferred the interface with an overview, stating that it supported navigation and helped keep track of their position on the map. However, subjects were faster with the interface without an overview when using one of the two maps. We conjecture that this difference was due to the organization of that map in multiple levels, which rendered the overview unnecessary by providing richer navigation cues through semantic zooming. The combination of that map and the interface without an overview also improved subjects ’ recall of objects on the map. Subjects who switched between the overview and the detail windows used more time, suggesting that integration of overview and detail windows adds complexity and requires additional mental and motor effort.

We present the ConnecTable, a new mobile, networked and context-aware information appliance that provides affordances for pen-based individual and cooperative work as well as for the seamless transition between the two. In order to dynamically enlarge an interaction area for the purpose of shared use, a flexible coupling of displays has been realized that overcomes the restrictions of display sizes and borders. Two ConnecTable displays dynamically form a homogeneous display area when moved close to each other. The appropriate triggering signal comes from built-in sensors allowing users to temporally combine their individual displays to a larger shared one by a simple physical movement in space. Connected ConnecTables allow their users to work in parallel on an ad-hoc created shared workspace as well as exchanging information by simply shuffling objects from one display to the other. We discuss the user interface and related issues as well as the software architecture. We also present the physical realization of the ConnecTables.

Calendar applications for small handheld devices are growing in popularity. This led us to develop DateLens, a novel calendar interface for PDAs designed to support complex tasks. It uses a fisheye representation coupled with compact overviews to give the big picture in a small space. The interface also gives users control over the visible time period, as well as supporting integrated search to discover patterns and outliers. Designed with device scalability in mind, DateLens currently runs on desktop computers as well as PDAs. Two user studies have been conducted to examine the viability of DateLens as a replacement for traditional calendar visualizations. In the first study, non-PDA users performed complex tasks significantly faster with DateLens than with the Microsoft Pocket PC 2002 ™ calendar (using a PDA emulator). In addition, they rated DateLens as being easier to use than the default calendar application for a majority of the tasks. In the second study, the participants were expert Pocket PC users and the software was run on their own devices. Again, DateLens performed significantly faster for the complex tasks, and there were satisfaction differences favoring each calendar for different kinds of tasks. From these studies, it is clear that DateLens is superior for more complex tasks such as those associated with longer time periods. For daily event tracking, users familiar with the default Pocket PC calendar strongly preferred its daily view and behaviors. Categories and Subject Descriptors:

As more information resources become accessible using computers, our digital interfaces to those resources need to be appropriate for all people. However when it comes to digital libraries, the interfaces have typically been designed for older children or adults. Therefore, we have begun to develop a digital library interface developmentally appropriate for young children (ages 5-10 years old). Our prototype system we now call "QueryKids" offers a graphical interface for querying, browsing and reviewing search results. This paper describes our motivation for the research, the design partnership we established between children and adults, our design process, the technology outcomes of our current work, and the lessons we have learned. Keywords Children, digital libraries, information retrieval design techniques, education applications, participatory design, cooperative inquiry, intergenerational design team, zoomable user interfaces (ZUIs). THE NEED FOR RESEARCH A growing body of k...

In ubiquitous computing environments, multiple users work with a wide range of different devices. In many cases, users interact and collaborate using multiple heterogeneous devices at the same time. The configuration of the devices should be able to change frequently due to a highly dynamic, flexible and mobile nature of new work practices. This produces new requirements for the architecture of an appropriate software infrastructure. In this paper, an architecture designed to meet these requirements is proposed. To test its applicability, this architecture was used as the basis for the implementation of BEACH, the software infrastructure of i-LAND (the ubiquitous computing environment at GMD-IPSI). It provides the functionality for synchronous cooperation and interaction with roomware components, i.e. room elements with integrated information technology. In conclusion, our experiences with the current implementation are presented.

We have designed two interfaces to support one-handed thumb use for PDAs and cell phones. Both use Scalable User Interface (ScUI) techniques to support multiple devices with different resolutions and aspect ratios. The designs use variations of zooming interface techniques to provide multiple views of application data: AppLens uses tabular fisheye to access nine applications, while LaunchTile uses pure zoom to access thirty-six applications. Two sets of thumb gestures represent different philosophies for one-handed interaction. We conducted two studies to evaluate our designs. The first study explored whether users could learn and execute the AppLens gesture set with only minimal training. Participants performed more accurately and efficiently using semantic gestures for directional navigation than abstract gestures for object interaction. A second study gathered user reactions to each interface, as well as comparative preferences. With minimal exposure to each design, most users favored the tabular fisheye interface.

Most analysts start with an overview of the data before gradually refining their view to be more focused and detailed. Multiscale panand-zoom systems are effective because they directly support this approach. However, generating abstract overviews of large data sets is difficult, and most systems take advantage of only one type of abstraction: visual abstraction. Furthermore, these existing systems limit the analyst to a single zooming path on their data and thus a single set of abstract views. This paper presents: (1) a formalism for describing multiscale visualizations of data cubes with both data and visual abstraction, and (2) a method for independently zooming along one or more dimensions by traversing a zoom graph with nodes at different levels of detail. As an example of how to design multiscale visualizations using our system, we describe four design patterns using our formalism. These design patterns show the effectiveness of multiscale visualization of general relational databases.