User Interfaces and Difference Visualizations for Alternatives

Designers often create multiple iterations to evaluate alternatives. Todays computer-based tools do not support such easy exploration of a design space, despite the fact that such support has been advocated. This dissertation is centered on this. I begin by investigating the effectiveness of various forms of difference visualizations and support for merging changes within a system targeted at diagrams with node and edge attributes. I evaluated the benefits of the introduced difference visualization techniques in two user studies. I found that the basic side-by-side juxtaposition visualization was not effective and also not well received. For comparing diagrams with matching node positions, participants preferred the side-by-side option with a difference layer. For diagrams with non-matching positions animation was beneficial, but the combination with a difference layer was preferred. Thus, the difference layer technique was useful and a good complement to animation. I continue by investigating if explicit support for design alternatives better supports exploration and creativity in a generative design system. To investigate the new techniques to better support exploration, I built a new system that supports parallel exploration of alternative designs and generation of new structural combinations. I investigate the usefulness of my prototype in two user studies and interviews. The results and feedback suggest and confirm that supporting design alternatives explicitly enables designers to work more creatively. Generative models are often represented as DAGs (directed acyclic graphs) in a dataflow programming environment. Existing approaches to compare such DAGs do not generalize to multiple alternatives. Informed by and building on the first part of my dissertation, I introduce a novel user interface that enables visual differencing and editing alternative graphsspecifically more than two alternatives simultaneously, something that has not been presented before. I also explore multi-monitor support to demonstrate that the difference visualization technique scales well to up to 18 alternatives. The novel jamming space feature makes organizing alternatives on a 23 monitor system easier. To investigate the usability of the new difference visualization method I conducted an exploratory interview with three expert designers. The received comments confirmed that it meets their design goals

On the effective visualisation of dynamic attribute cascades

Cascades appear in many applications, including biological graphs and social media analysis. In a cascade, a dynamic attribute propagates through a graph, following its edges. We present the results of a formal user study that tests the effectiveness of different types of cascade visualisations on node-link diagrams for the task of judging cascade spread. Overall, we found that a small multiples presentation was significantly faster than animation with no significant difference in terms of error rate. Participants generally preferred animation over small multiples and a hierarchical layout to a force-directed layout. Considering each presentation method separately, when comparing force-directed layouts to hierarchical layouts, hierarchical layouts were found to be significantly faster for both presentation methods and significantly more accurate for animation. Representing the history of the cascade had no significant effect. Thus, for our task, this experiment supports the use of a small multiples interface with hierarchically drawn graphs for the visualisation of cascades. This work is important because without these empirical results, designers of dynamic multivariate visualisations (in many applications) would base their design decisions on intuition with little empirical support as to whether these decisions enhance usability

Animating the evolution of software

The use and development of open source software has increased significantly in the last decade. The high frequency of changes and releases across a distributed environment requires good project management tools in order to control the process adequately. However, even with these tools in place, the nature of the development and the fact that developers will often work on many other projects simultaneously, means that the developers are unlikely to have a clear picture of the current state of the project at any time. Furthermore, the poor documentation associated with many projects has a detrimental effect when encouraging new developers to contribute to the software. A typical version control repository contains a mine of information that is not always obvious and not easy to comprehend in its raw form. However, presenting this historical data in a suitable format by using software visualisation techniques allows the evolution of the software over a number of releases to be shown. This allows the changes that have been made to the software to be identified clearly, thus ensuring that the effect of those changes will also be emphasised. This then enables both managers and developers to gain a more detailed view of the current state of the project. The visualisation of evolving software introduces a number of new issues. This thesis investigates some of these issues in detail, and recommends a number of solutions in order to alleviate the problems that may otherwise arise. The solutions are then demonstrated in the definition of two new visualisations. These use historical data contained within version control repositories to show the evolution of the software at a number of levels of granularity. Additionally, animation is used as an integral part of both visualisations - not only to show the evolution by representing the progression of time, but also to highlight the changes that have occurred. Previously, the use of animation within software visualisation has been primarily restricted to small-scale, hand generated visualisations. However, this thesis shows the viability of using animation within software visualisation with automated visualisations on a large scale. In addition, evaluation of the visualisations has shown that they are suitable for showing the changes that have occurred in the software over a period of time, and subsequently how the software has evolved. These visualisations are therefore suitable for use by developers and managers involved with open source software. In addition, they also provide a basis for future research in evolutionary visualisations, software evolution and open source development

Can animation support the visualisation of dynamic graphs?

Animation and small multiples are methods for visualizing dynamically evolving graphs. Animations present an interactive movie of the data where positions of nodes are smoothly interpolated as the graph evolves. Nodes fade in/out as they are added/removed from the data set. Small multiples presents the data like a comic book with the graph at various states in separate windows. The user scans these windows to see how the data evolves. In a recent experiment, drawing stability (known more widely as the “mental map”) was shown to help users follow specific nodes or long paths in dynamically evolving data. However, no significant difference between animation and small multiples presentations was found. In this paper, we look at data where the nodes in the graph have low drawing stability and analyze it with new error metrics: measuring how close the given answer is from the correct answer on a continuous scale. We find evidence that when the stability of the drawing is low and important nodes in the task cannot be highlighted throughout the time series, animation can improve task performance when compared to the use of small multiples

GraphDiaries: Animated Transitions and Temporal Navigation for Dynamic Networks

International audienceIdentifying, tracking and understanding changes in dynamic networks are complex and cognitively demanding tasks. We present GraphDiaries, a visual interface designed to improve support for these tasks in any node-link based graph visualization system. GraphDiaries relies on animated transitions that highlight changes in the network between time steps, thus helping users identify and understand those changes. To better understand the tasks related to the exploration of dynamic networks, we first introduce a task taxonomy, that informs the design of GraphDiaries, presented afterwards. We then report on a user study, based on representative tasks identified through the taxonomy, and that compares GraphDiaries to existing techniques for temporal navigation in dynamic networks, showing that it outperforms them in terms of both task time and errors for several of these tasks

Browsing Icons: A Task-Based Approach for a Visual Web History

We have implemented a task and session based visual web history tool called Browsing Icons that dynamically draws animated graphs of the user's paths through the web. Using a proxy, it can be attached to any common web browser. Every web session builds an individual Browsing Graph with a characteristic shape. The graphs are organized in a hierarchy of user-defined tasks. Users can interrupt tasks and continue later using the graphs that provide access to all the web pages they have visited so far. The graphs can be reused for similar or recurrent tasks. By clustering the history hierarchically according to tasks, we try to cope with scale and to provide a powerful concept for easy revisitation. The visualizations have been implemented using the Jazz framework for zoomable user interfaces (ZUIs) in Java. A usability study showed that users like the system very much and appreciate its support of revisiting web pages. Ten users revisited web pages after a few minutes and other web pages after one to six days using both Netscape with Browsing Icons and Netscape alone. With the tool they completed the short-term revisits in 84% of the time required when using Netscape alone. The revisits after one to six days users could accomplish in 57.8% of the time they needed when using Netscape, thereby visiting only 53.8% as many pages. Users were significantly more satisfied with Browsing Icons than with pure Netscape. KEYWORDS: Web History Visualization, Task Based Information Organization, Information Visualization, Web Browser Usability, Jazz. UMIACS-TR-2001-85 HCIL-TR-2001-1

Zoomable User Interfaces for the Authoring and Delivery of Slide Presentations

Millions of slide presentations are being authored and delivered with computer software every day. Yet much of the computer's power for these tasks remains untapped. Existing interaction techniques leave presenters wrestling with limited size computer displays to get meaningful overviews of their work. Without these overviews, they have trouble finding patterns in their data and experimenting with alternate organizations. They also have difficulty communicating the structure of large or complex talks to the audience and keeping the audience oriented during unexpected transitions between ideas. A natural solution is Zoomable User Interfaces (ZUIs) since they offer the capability to view information at multiple levels of detail and smoothly transition between ideas. This work presents two ZUIs, Niagara and CounterPoint, for authoring and delivering slide presentations. Niagara is a ZUI workspace for authoring presentation content with techniques to improve authoring in the zoomable environment. Empirical evaluations of ZUI-based authoring tools revealed performance improvements and subjective preferences over folder-based interfaces for organization tasks. Users were 30% faster with ZUIs than with folders in completing a simplified shape organization task. Some classes of users were also faster with ZUIs than with folders in completing a text-based organization task. Users performing both tasks exhibited a strong preference for ZUIs over folders. CounterPoint provides a number of features to simplify the creation and delivery of ZUI presentations. The effects of these presentations on the audience were evaluated in a controlled comparison of presentations with slides only, slides with spatial layouts, and slides with spatial layouts and animation. The study revealed a strong subjective preference and higher ratings of organization for presentations with spatial layout. Feedback was also gathered from presenters who used CounterPoint to deliver over 100 real-world presentations. They indicated that CounterPoint helped them communicate overviews and multi-level presentation structures. More experienced CounterPoint presenters also found that CounterPoint helped them keep the audience oriented when navigating the presentation in response to audience feedback

How to tell stories using visualization: strategies towards narrative visualization

Os benefícios da utilização das narrativas são desde há muito conhecidos e o seu potencial para simplificar conceitos, transmitir valores culturais e experiências, criar ligações emocionais e capacidade para ajudar a reter a informação tem sido explorado em diferentes áreas. As narrativas não são só a principal forma como as pessoas obtêm o sentido do mundo, mas também a forma mais fácil que encontrámos para partilhar informações complexas. Devido ao seu potencial, as narrativas foram recentemente abordadas na área da Visualização de Informação e do Conhecimento, muitas vezes apelidada de Visualização Narrativa. Esta questão é particularmente importante para os media, uma das áreas que tem impulsionado a investigação em Visualização Narrativa. A necessidade de incorporar histórias nas visualizações surge da necessidade de partilhar dados complexos de um modo envolvente. Hoje em dia somos confrontados com a elevada quantidade de informação disponível, um desafio difícil de resolver. Os avanços da tecnologia permitiram ir além das formas tradicionais de narrativa e de representação de dados, dando-nos meios mais atraentes e sofisticados para contar histórias. Nesta tese, exploro os benefícios da introdução de narrativas nas visualizações. Adicionalmente também exploro formas de combinar histórias com a visualizações e métodos eficientes para representar e dar sentido aos dados de uma forma que permite que as pessoas se relacionem com a informação. Esta investigação está bastante próxima da área do jornalismo, no entanto estas técnicas podem ser aplicadas em diferente áreas (educação, visualização científica, etc.). Para explorar ainda mais este tema foi adotada um avaliação que utiliza diferentes metodologias como a tipologia, vários casos de estudo, um estudo com grupos de foco, e ainda estudos de design e análise de técnicas.The benefits of storytelling are long-known and its potential to simplify concepts, convey cultural values and experiences, create emotional connection, and capacity to help retain information has been explored in di erent areas, such as journalism, education, marketing, and others. Narratives not only have been the main way people make sense of the world, but also the easiest way humans found out to share complex information. Due to its potential narratives have also recently been approached in the area of Information and Knowledge Visualization, several times being referred to as Narrative Visualization. This matter is also particularly important for news media, one of the areas that has been pushing the research on Narrative Visualization. The necessity to incorporate storytelling in visualizations arises from the need to share complex data in a way that is engaging. Nowadays we also have the challenge of the high amount of information available, which can be hard to cope with. Advances in technology have enabled us to go beyond the traditional forms of storytelling and representing data, giving us more attractive and sophisticated means to tell stories. In this dissertation, I explore the benefits of infusing visualizations with narratives. In addition I also present ways of combining storytelling with visualization and e cient methods to represent and make sense of data in a way that allows people to relate with the information. This research is closely related to journalism, but these techniques can be applied to completely di erent areas (education, scientific visualization, etc.). To further explore this topic a mixedmethod evaluation that consists of a typology, several case studies and a focus group study was chosen, as well as design studies and techniques review. This dissertation is intended to contribute to the evolving understanding of the field of narrative visualization

Comprendre et Concevoir les Animations dans le Contexte des Interfaces Graphiques

International audienceAnimations are increasingly used in interactive systems in order to enhance the usability and aesthetics of user interfaces. While animations are proven to be useful in many cases, we still find defective animations causing many problems, such as distracting users from their main task or making data exploration slower. The fact that such animations still exist proves that animations are not yet very well understood as a cognitive aid for understanding interfaces, and that we did not definitely decide what makes a well designed animation. This thesis aims at better understanding the different aspects of animations for user interfaces and exploring new methods and guidelines for designing them, with a main focus on the field of information visualization. As a first investigation, we elaborated a taxonomy of the roles of animations in the gra-phical interfaces. In the context of dynamic information visua-lizations, we are currently working on a model of animated transitions. We are also exploring certain aspects of the visual grouping for these transitions. Moreover, we are studying the impact of temporal structuring of animated transitions on the interpretation of data. Our future investigations will aim essentially at the design of a sketch-based tool for prototyping and authoring animated transitions of dynamic data.Les animations sont de plus en plus utilisées dans les systèmes interactifs dans un but d'améliorer l'utilisabilité et l'esthétique de l'interface utilisateur. Si les animations se révèlent très utiles dans de nombreux cas, on trouve également des anima-tions causant de multiples problèmes, tels que la distraction des utilisateurs de leur tâche principale ou encore le ralen-tissement de l'exploration des données. Le fait que de telles animations subsistent encore prouve que les animations ne sont pas encore bien assimilées comme une aide cognitive à la compréhension des interfaces, et que l'on n'a pas décisivement défini ce qui constitue une animation bien conçue. Le but de cette thèse est de mieux comprendre les différents aspects des animations pour les interfaces et d'explorer de nou-velles méthodes pour les concevoir, en focalisant une grande partie de nos travaux autour du domaine de la visualisation d'information. Comme première investigation, nous avons élaboré une taxonomie des rôles des animations dans les interfaces graphiques. Dans le contexte des visualisations dy-namiques d'information, nous travaillons actuellement sur un modèle des transitions animées. Nous explorons également certains aspects du groupement visuel pour ces transitions. En outre, nous étudions l'effet de la structuration temporelle des transitions animées sur l'interprétation des données. Nos futures investigations viseront essentiellement la conception d'un outil de prototypage et de création de transitions animées pour des données dynamiques basé sur le dessin