Martijn van Welie

Task based groupware design: putting theory into practice

Designing Groupware systems requires methods and tools that cover all aspects of Groupware systems. We present a method that utilizes known theoretical insights and makes them usable in practice. In our method, the design of Groupware systems is driven by an extensive task analysis followed by structured design and iterative evaluation using usability criteria. Using a combination of multiple complementary representations and techniques, a wide range of aspects of Groupware design is covered. The method is built on our experiences and is used in practice by several companies and educational institutes in Europe. We define the design process, the models needed and the tools that support the design process.

Bridging patterns: An approach to bridge gaps between SE and HCI

Adding usability improving solutions during late stage development is to some extent restricted by the software architecture. However, few software engineers and human-computer interaction engineers are aware of this important constraint and as a result avoidable rework is frequently necessary. In this paper we present a new type of pattern called a bridging pattern. Bridging patterns extend interaction design patterns by adding information on how to generally implement this pattern. Bridging patterns can be used for architectural analysis: when the generic implementation is known, software architects can assess what it means in their context and can decide whether they need to modify the software architecture to support these patterns. This may prevent part of the high costs incurred by adaptive maintenance activities once the system has been implemented and leads to architectures with better support for usability.

Jamming (on) the Web

Abstract The Web has become a dominant medium for the dissemination of information and, more recently, for collaborative work as well. The focus has been mainly on textual and graphical information, hardly addressing topics related to musical information. We present a framework that makes musical works accessible for Web users by offering high level support for the display of musical material on the Web as well as for live jam sessions. Our framework consists of a browser plug-in that supports the display and editing of scores as well as playing scores by connecting to a shared MIDI server. To participate in a jam session, clients of the MIDI server can also send data in real time, for instance by using a keyboard embedded in a Web page. We discuss the issues involved in displaying musical material on the Web and we sketch the technical architecture of our framework.

Usability Properties in Dialog Models

Usability has gained a lot of attention in the design community and it is one of main goals of every design project. Evaluating usability is usually done with end-users after a prototype has been built and there are not many techniques available that allow usability evaluation during the early design phases. Current dialog modeling techniques generally do not deal with usability aspects, as they are often functional based models, dealing only with states and state changes. This paper investigates how usability aspects can be incorporated into dialog models so that usability can be evaluated during the design process without doing usage tests. A set of measurable properties is given which together could give an indication about the usability of the design, This way, some usability aspects can be covered early in the design process without the need for an executable prototype or end-users.