Human-Computer Interaction Series Series Editors John Karat IBM Thomas J. Watson Research Center, 30 Saw Mill River Road, Hawthorne, NY 10532, U. E-mail: jkarat@us.com Jean Vanderdonckt Université catholique de Louvain, Place des Doyens, 1, (office a112), 1348 Louvain- La-Neuve, Belgium E-mail: vanderdonckt@isys.be Series Editorial Board Gaëlle Calvary, LIG-University of Grenoble 1, Grenoble, France John Carroll, School of Information Sciences & Technology, Penn State University, U. Gilbert Cockton, Northumbria University, Newcastle, U.
Larry Constantine, University of Madeira, Portugal, and Constantine & Lockwood Ltd, Massachusetts, U. Steven Feiner, Columbia University, New York, U. Peter Forbrig, Universität Rostock, Rostock, Germany Elizabeth Furtado, University of Fortaleza, Fortaleza, Brazil Hans Gellersen, Lancaster University, Lancaster, U. Robert Jacob, Tufts University, Oregon, U.
Hilary Johnson, University of Bath, Bath, U. Kumiyo Nakakoji, University of Tokyo, Tokyo, Japan Philippe Palanque, Université Paul Sabatier, Toulouse, France Oscar Pastor, University of Valencia, Valencia, Spain Fabio Pianesi, Bruno Kessler Foundation (FBK), Trento, Italy Costin Pribeanu, National Institute for Research & Development in Informatics, Bucharest, Romania Gerd Szwillus, Universität Paderborn, Paderborn, Germany Manfred Tscheligi, University of Salzburg, Salzburg, Austria Gerrit van der Veer, University of Twente, Twente, The Netherlands Shumin Zhai, IBM Almaden Research Center, California, U. Thomas Ziegert, SAP Research CEC Darmstadt, Darmstadt, Germany Human-computer interaction is a multidisciplinary field focused on human aspects of the development of computer technology. As computer-based technology becomes increasingly pervasive – not just in developed countries, but worldwide – the need to take a human- centered approach in the design and development of this technology becomes ever more important.
For roughly 30 years now, researchers and practitioners in computational and be- havioral sciences have worked to identify theory and practice that influences the direction of these technologies, and this diverse work makes up the field of human-computer interaction. Broadly speaking it includes the study of what technology might be able to do for people and how people might interact with the technology. In this series we present work which advances the science and technology of developing systems which are both effective and satisfying for people in a wide variety of contexts. The Human-Computer Interaction series will focus on theoretical perspectives (such as formal approaches drawn from a variety of behavioral sciences), practical approaches (such as the techniques for effectively integrating user needs in system development), and social issues (such as the determinants of utility, usability and acceptability).
For further volumes: www.com/series/6033 Wolfgang Aigner r Silvia Miksch r Heidrun Schumann r Christian Tominski Visualization of Time-Oriented Data Wolfgang Aigner Heidrun Schumann Vienna University of Technology University of Rostock Vienna Rostock Austria Germany Silvia Miksch Christian Tominski Vienna University of Technology University of Rostock Vienna Rostock Austria Germany ISSN 1571-5035 ISBN 978-0-85729-078-6 e-ISBN 978-0-85729-079-3 DOI 10.1007/978-0-85729-079-3 Springer London Dordrecht Heidelberg New York British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Control Number: 2011929628 © Springer-Verlag London Limited 2011 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as per- mitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publish- ers, or in the case of reprographic reproduction in accordance with the terms of licenses issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. The use of registered names, trademarks, etc., in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore free for general use. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made.
Cover design: VTeX UAB, Lithuania Printed on acid-free paper Springer is part of Springer Science+Business Media (www.com) To our families. Foreword Time is central to life. We are aware of time slipping away, being used well or poorly, or of having a great time. Thinking about time causes us to reflect on the biological evolution over millennia, our cultural heritage, and the biographies of great personalities.
It also causes us to think personally about our early life or the business of the past week. But thinking about time is also a call to action, since inevitably we must think about the future – the small decisions about daily meetings, our plans for the next year, or our aspirations for the next decades. Reflections on time for an individual can be facilitated by visual representations such as medical histories, vacation plans for a summer trip, or plans for five years of university study to obtain an advanced degree. These personal reflections are enough justification for research on temporal visualizations, but the history and plans of or- ganizations, communities, and nations are also dramatically facilitated by powerful temporal visual tools that enable exploration and presentation.
Even more complex problems emerge when researchers attempt to understand biological evolution, ge- ological change, and cosmic scale events. For the past 500 years circular clock faces have been the prime representation for time data. These emphasize the twelve or 24-hour cycles of days, but some clocks include week-day, month or year indicators as well. For longer time periods, time lines are the most widely used, by historians as well as geologists and cosmologists.
The rise of computer display screens opened up new opportunities for time dis- plays, challenging but not displacing the elegant circular clock face. Digital time displays are neatly discrete, clear and compact, but make time intervals harder to understand and compare. Increased use of linear time displays on computers has come with new opportunities for showing multiple time points, intervals, and future events. However, a big benefit of using computer displays is that multiple temporal variables can be shown above or below, or on the same time line.
These kinds of overviews pack far more information in a compact space than was previously possi- ble, while affording interactive exploration by zooming and filtering. Users can then see if the variables move in the same or opposite directions, or if one movement consistently precedes the other, suggesting causality. vii viii Foreword These rich possibilities have payoffs in many domains including medical histo- ries, financial or economic trends, and scientific analyses of many kinds. However, the design of interfaces to present and manipulate these increasingly complex and large temporal datasets has a dramatic impact on the users’ efficacy in making dis- coveries, confirming hypotheses, and presenting results to others.
This book on Visualization of Time-Oriented Data by Aigner, Miksch, Schumann and Tominski represents an important contribution for researchers, practitioners, de- signers, and developers of temporal interfaces as it focuses attention on this topic, drawing together results from many sources, describing inspirational prototypes, and providing thoughtful insights about existing designs. While I was charmed by the historical review, especially the inclusion of Duchamp and Picasso’s work, the numerous examples throughout the book showed the range of possibilities that have been tried – successes as well as failures. The analysis of the user tasks and inter- action widgets made for valuable reading, provoking many thoughts about the work that remains to be done. In summary, this book is not only about work that has been done, but it is also a call to action, to build better systems, to help decision makers, and to make a better world.
University of Maryland, Ben Shneiderman February 2011 Preface Time is an exceptional dimension. We recognize this every day: when we are waiting for a train, time seems to run at a snail’s pace, but the hours we spend in a bar with a good friend pass by so quickly. There are times when one can wait endlessly for something to happen, and there are times when one is overwhelmed by events oc- curring in quick succession. Or it can happen that the weather forecast has predicted a nice and sunny summer day, but our barbecue has to be canceled due to a sudden heavy thunderstorm.
Our perception of the world around us and our understanding of relations and models that drive our everyday life are profoundly dependent on the notion of time. As visualization researchers, we are intrigued by the question of how this impor- tant dimension can be represented visually in order to help people understand the temporal trends, correlations, and patterns that lie hidden in data. Most data are re- lated to a temporal context; time is often inherent in the space in which the data have been collected or in the model with which the data have been generated. Seen from the data perspective, the importance of time is reflected in established self-contained research fields around temporal databases or temporal data mining.
However, there is no such sub-field in visualization, although generating expressive visual represen- tations of time-oriented data is hardly possible without appropriately accounting for the dimension of time. When we first met, we had all already collected experience in visualizing time and time-oriented data, be it from participating in corresponding research projects or from developing visualization techniques and software tools. And the literature had already included a number of research papers on this topic at that time. Yet despite our experience and the many papers written, we recognized quite early in our col- laboration that neither we nor the literature spoke a common (scientific) language.
So there was a need for a systematic and structured view of this important aspect of visualization. We present such a view in this book – for scientists conducting related research as well as for practitioners seeking information on how their time-oriented data can be visualized in order to achieve the bigger goal of understanding the data and gaining valuable insights. We arrived at the systematic view upon which this book is based ix x Preface in the course of many discussions, and we admit that agreeing on it was not such an easy process. Naturally, there is still room for arguments to be made and for extensions of the view to be proposed.
Nonetheless, we think that we have managed to lay the structural foundation of this area. The practitioner will hopefully find the many examples that we give throughout the book useful. On top of this, the book offers a substantial survey of visualization techniques for time and time-oriented data. Our goal was to provide a review of existing work structured along the lines of our systematic view for easy visual ref- erence.
Each technique in the survey is accompanied by a short description, a visual impression of the technique, and corresponding categorization tags. But visual rep- resentations of time and time-oriented data are not an invention of the computer age. In fact, they have ancient roots, which will also be showcased in this book. A dis- cussion of the closely related aspects of user interaction with visual representations and analytical methods for time-oriented data rounds off the book.
We now invite you to join us on a journey through time – or more specifically on a journey into the visual world of time and time-oriented data. Vienna University of Technology & Wolfgang Aigner University of Rostock, Silvia Miksch February 2011 Heidrun Schumann Christian Tominski About the Authors Wolfgang Aigner is assistant professor at the Institute of Software Technology & Interactive Systems at Vienna University of Technology, Austria. He received his PhD in computer science in 2006 for his work on “Visualization of Time and Time-Oriented Information: Challenges and Conceptual Design”. From 2006 to 2010 he was research associate and deputy head of the Department of Informa- tion and Knowledge Engineering at Danube University Krems, Austria.
Wolfgang has authored and co-authored several dozens of peer-reviewed articles and served as reviewer and program committee member for various scientific conferences, sym- posia, and workshops.