Software visualization tools face many challenges in terms of their implementation, including scalability, usability, adaptability, and durability. Such tools, like many other research tools, tend to have a short life cycle and are vulnerable to software evolution processes because of the complex problem domain and the constantly changing requirements which are dictated by research goals. In this paper we discuss the implementation of the software visualization tool CodeCrawler according to five criteria, namely the overall architecture, the internal architecture, the visualization engine, the metamodel and the interactive facilities. This discussion generates implementation recommendations and design guidelines that hold for our tool and the class of tools its stands for. We then also extract common design guidelines and recommendations that apply for other software visualization and general reverse engineering tools as well, and hope that these insights can be used fruitfully by other researchers in this field.

As software strives to provide more fine-grained support for a wider range of people and activities, the need for designers and developers to understand human behavior has grown. Usability or user research professionals collect and work to comprehend data from diverse sources, seeking to translate this understanding into an ability to anticipate user responses to designs. Even more challenging, they will be more eKective if they can communicate their understanding to other team members who help in the design, development, and testing process. Personas is an interaction design technique that has demonstrated considerable potential for achieving these goals in software product development. Personas are fictional characters, based on actual data, that depict target user populations. The Persona method builds on previous research eKorts, notably in marketing, and was popularized by Alan Cooper in his 1999 book, The Inmates are Running the Asylum. 1 Personas consist of fully fleshed out fictional characters, as might be

The design of commercial products that are intended to serve millions of people has been a challenge for collaborative approaches. The creation and use of fictional users, concrete representations commonly referred to as ‘personas’, is a relatively new interaction design technique. It is not without problems and can be used inappropriately, but based on experience and analysis it has extraordinary potential. Not only can it be a powerful tool for true participation in design, it also forces designers to consider social and political aspects of design that otherwise often go unexamined.

Patterns describe generic solutions to common problems in context. Originating from the world of architecture, patterns have been used mostly in object-oriented programming and data analysis. The goal of HCI patterns is to create an inventory of solutions to help designers (and usability engineers) to resolve UI development problems that are common, difficult and frequently encountered. In this paper, we present our pattern-supported approach to user interface design in the context of information visualization. Using a concrete example from the telecommunications domain, we will focus on a task/subtask pattern to illustrate how knowledge about a task and an appropriate interaction design solution can be captured and communicated. 1

The UML is recognized to be the dominant diagrammatic modeling language in the software industry. However, its support for building interactive systems is still acknowledged to be insufficient. There is a common misconception that the same models developed to support the design of the application internals are also adequate to support interaction design, leveraging the usability aspects of the applications. In this paper we identify and discuss the major problems using the UML to document, specify and design interactive systems. Here we propose a UML profile for interactive systems development that leverages on human-computer interaction domain knowledge under the common notation and semantics of the UML. Our proposal integrates with existing object-oriented software engineering best practice, fostering co-evolutionary development of interactive systems and enabling artifact change between software engineering and human-computer interaction. 1

ii Computer software has become increasingly complex as advances in technology permit substantially more functionality to be provided to the user, a phenomenon which has led some people to describe today’s heavily featured software as “bloated”. Despite the prevalence of this trend, the impact of complexity on the user has received little attention in the research community. This dissertation describes research that addresses that problem. Study One, a comprehensive study that looked at the experience of 53 users of Microsoft Word, showed that while many users would like to have unused functions “tucked away”, most users were uncomfortable with the complete removal of unused functions. These findings suggested personalization as a promising direction for design and led to our Pilot Study which evaluated a multiple-interfaces prototype for Microsoft Word, where one of the interfaces was personalized to the user’s individual needs. Results from that informal Wizard-of-Oz evaluation with 4 participants encouraged refinement of our prototype. Study Two, a field study that included 20 participants, tested the effects of different interface

This article describes a case study that examined one procurer’s reasoning about and work with usabilityrelated issues as well as the contractor’s response to those requirements. The aim of this study was to examine the procurer’s power to direct the system development process according to user-centred principles and indeed to point out its responsibility to use that power. The study elucidated the procurer’s and the contractor’s differing views of usability. The results suggest that the project leaders from the two organisations examined in this study had differing views of usability and that both approached usability more from a business perspective than from a user perspective. Furthermore, we found that the procurer valued user-centred activities less for their results than for the opportunity they gave to come in contact with the user’s point of view and then to visualize the requirements concretely. We conclude this article with an analysis of some contradictions within and between the two organisations from a socio-cultural point of view. We suggest some mundane but nevertheless important requirements that procurers should think of when contracting consultants.

We present an algorithm called the Best Trail Algorithm, which helps solve the hypertext navigation problem by automating the construction of memex-like trails through the corpus. The algorithm performs a probabilistic best-first expansion of a set of navigation trees to find relevant and compact trails. We describe the implementation of the algorithm, scoring methods for trails, filtering algorithms and a new metric called potential gain which measures the potential of a page for future navigation opportunities.

Extreme Programming appears to be a solution for discovering and meeting requirements faster (through close customer collaboration) as well as creating quality software. In practice we found XP did deliver high quality software quickly, but the resulting product still failed to delight the customer. Although the finished product should have been an exact fit, the actual end-user still ended up slogging through the system to accomplish necessary day-to-day work. This paper describes using interaction design in an agile development process to resolve this issue. Using interaction design as a day-to-day practice throughout an iterative development process helps our team at Tomax Technologies deliver high quality software, while feeling confident the resulting software will more likely meet end-user expectations. The method of Interaction Design followed here is based on Constantine and Lockwood’s Usage-Centered Design. Recommendations are provided on how to practice an agile form of U-CD and how to incorporate bits of Interaction Design thinking into every day development and product planning decisions.

There are two main kinds of approach to considering usability of any system: empirical and analytical. Empirical techniques involve testing systems with users, whereas analytical techniques involve usability personnel assessing systems using established theories and methods. We report here on a set of studies in which four different techniques were applied to various digital libraries, focusing on the strengths, limitations and scope of each approach. Two of the techniques, Heuristic Evaluation and Cognitive Walkthrough, were applied in text-book fashion, because there was no obvious way to contextualize them to the Digital Libraries (DL) domain. For the third, Claims Analysis, it was possible to develop a set of re-usable scenarios and personas that relate the approach specifically to DL development. The fourth technique, CASSM, relates explicitly to the DL domain by combining empirical data with an analytical approach. We have found that Heuristic Evaluation and Cognitive Walkthrough only address superficial aspects of interface design (but are good for that), whereas Claims Analysis and CASSM can help identify deeper conceptual difficulties (but demand greater skill of the analyst). However, none fit seamlessly with existing digital library development practices, highlighting an important area for further work to support improved usability.