software

The various fields associated with interactive software systems engage in design activities to enable people who would use the resulting systems to meet goals, coordinate with others, find meaning, and express themselves in myriad ways. Yet many development projects fail, and we all have contact with clumsy software-based systems that force work-arounds and impose substantial attentional, knowledge and workload burdens. On the other hand, field observations reveal people re-shaping the artifacts they encounter and interact with as resources to cope with the demands of the situations they face as they seek to meet their goals. In this process some new devices are quickly seized upon and exploited in ways that transform the nature of human activity, connections, and expression.

The software intensive interactive systems and devices under development around us are valuable to the degree that they expand what people in various roles and organizations can achieve. How can we measure this value provided to others? Are current measures of usability adequate? Does creeping complexity wipe out incremental gains as products evolve? Do designers and developers mis-project the impact when systems-to-be-realized are fielded? Which technology changes will trigger waves of expansive adaptations that transform what people do and even why they do it.

Sponsors of projects to develop new interactive software systems are asking developers for tangible evidence of the value to be delivered to those people responsible for activities and goals in the world. Traditional measures of usability and human performance seem inadequate. Cycles of inflation in the claims development organizations make (and the legacy of disappointment and surprise) have left sponsors numb and eroded trust. Thus, we need to provide new forms of evidence about the potential of new interactive systems and devices to enhance human capability.

Luckily, this need has been accompanied by a period of innovation in ways to measure the impact of new designs on:

• growth of expertise in roles,
• synchronizing activities over wider scopes and ranges,
• expanding adaptive capacities.

This talk reviews a few of the new measures being tested in each of these categories, points to some of the underlying science, and uses these examples to trigger discussion about how design of future interactive software provides will provide value to stakeholders.

Employee directories play a valuable role in helping people find others to collaborate with, solve a problem, or provide needed expertise. Serving this role successfully requires accurate and up-to-date user profiles, yet few users take the time to maintain them. In this paper, we present a system that enables users to tag other users with key words that are displayed on their profiles. We discuss how people-tagging is a form of social bookmarking that enables people to organize their contacts into groups, annotate them with terms supporting future recall, and search for people by topic area. In addition, we show that people-tagging has a valuable side benefit: it enables the community to collectively maintain each others' interest and expertise profiles. Our user studies suggest that people tag other people as a form of contact management and that the tags they have been given are accurate descriptions of their interests and expertise. Moreover, none of the people interviewed reported offensive or inappropriate tags. Based on our results, we believe that peopletagging will become an important tool for relationship management in an organization.

Involving graphic designers in the large-scale development of user interfaces requires tools that provide more graphical flexibility and support efficient software processes. These requirements were analysed and used in the design of the TkZ-inc graphical library and the IntuiKit interface design environment. More flexibility is obtained through a wider palette of visual techniques and support for iterative construction of images, composition and parametric displays. More efficient processes are obtained with the use of the SVG standard to import graphics, support for linking graphics and behaviour, and a unifying model-driven architecture. We describe the corresponding features of our tools, and show their use in the development of an application for airports. Benefits include a wider access to high quality visual interfaces for specialised applications, and shorter prototyping and development cycles for multidisciplinary teams.

We explore the use of abstracted screenshots as part of a new help interface. Graphstract, an implementation of a graphical help system, extends the ideas of textually oriented Minimal Manuals to the use of screenshots, allowing multiple small graphical elements to be shown in a limited space. This allows a user to get an overview of a complex sequential task as a whole. The ideas have been developed by three iterations of prototyping and evaluation. A user study shows that Graphstract helps users perform tasks faster on some but not all tasks. Due to their graphical nature, it is possible to construct Graphstracts automatically from pre-recorded interactions. A second study shows that automated capture and replay is a low-cost method for authoring Graphstracts, and the resultant help is as understandable as manually constructed help.

Nova is a simple technique for animating a data sequence whose elements include a primary numeric component and possibly one or more secondary dimensions. We use nova to visualize program behavior such as individual memory allocations, where the number of bytes in each allocation is a natural primary numeric dimension.

This paper describes a domain-specific debugger for one-way constraint solvers. The debugger makes use of several new techniques. First, the debugger displays only a portion of the dataflow graph, called a constraint slice, that is directly related to an incorrect variable. This technique helps the debugger scale to a system containing thousands of constraints. Second, the debugger presents a visual representation of the solver's data structures and uses color encodings to highlight changes to the data structures. Finally, the debugger allows the user to point to a variable that has an unexpected value and ask the debugger to suggest reasons for the unexpected value. The debugger makes use of information gathered during the constraint satisfaction process to generate plausible suggestions. Informal testing has shown that the explanatory capability and the color coding of the constraint solver's data structures are particularly useful in locating bugs in constraint code.

This paper describes a Computer Aided Design system for sketching free-form polygonal surfaces such as terrains and other natural objects. The user manipulates two 3D position and orientation trackers with three buttons, one for each hand. Each hand has a distinct role to play, with the dominant hand being responsible for picking and manipulation, and the less-dominant hand being responsible for context setting of various kinds. The less-dominant hand holds the workpiece, sets which refinement level that can be picked by the dominant hand, and generally acts as a counterpoint to the dominant hand. In this paper, the architecture of the system is outlined, and a simple surface is shown.