Supporting Webpage Revisiting with History Data and Visualization Trien Van Do Submitted in accordance with the requirements for the degree of Doctor of Philosophy The University of Leeds School of Computing March, 2013 - ii - The candidate confirms that the work submitted is his own, except where work which has formed part of jointly-authored publications has been included. The contribution of the candidate and the other authors to this work has been explicitly indicated below. The candidate confirms that appropriate credit has been given within the thesis where reference has been made to the work of others. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be published without proper acknowledgement. The right of Trien Van Do to be identified as Author of this work has been asserted by him in accordance with the Copyright, Designs and Patents Act 1988. © 2013 The University of Leeds and Trien Van Do - iii - Declarations Chapter 5 of this thesis has been based on work from the jointly-authored publication below. All the material in this publication is my own work under the supervision of Dr Roy Ruddle. Do, T.V., & Ruddle, R. A. (2012). The design of a visual history tool to help users refind information within a website. In: Proceedings of the 34th European Conference on Information Retrieval (ECIR 2012). Spinger-Verlag, 459-462. - iv - To my family, teachers, and friends. - v - Acknowledgements My PhD has been a three and a half year journey and I have enjoyed all of its ups and downs. I would like to take this opportunity to extend my thanks to the following people who have supported me along the way. Firstly, I am very grateful to my supervisor Dr Roy Ruddle, my mentor Dr Vania Dimitrova, and Professor Ken Brodlie. Roy, I cannot thank you enough for being such a great supervisor, for having enough faith in my abilities to give me the chance to do this PhD with you; from the moment you asked what I did in my free time in the application interview, I knew it would be enjoyable to work with you. Vania, thanks for your sharp questions in my assessments which helped me think through my research, for social events within the School of Computing and with your research group, and for your support. Ken, thank you, you are an inspiration; it has been a privilege to have the benefit of your counsel. I would like to thank Dr Lydia Lau and Dr Max Wilson, my examiners, for their useful suggestions for improving the final version of my thesis. I would also like to thank the members of the Visualization and Virtual Reality Group, past and present, for making the trip a pleasant one. Thanks Chris Rooney for helping me find my feet in my first days in Leeds. Special thanks to Jeremy Swann for being such a great companion on the journey. Thanks also go to the administration and support staff in the School of Computing and the University of Leeds for keeping everything running smoothly. Especially, this research could have not been conducted without a Fully Funded International Research Scholarship by the University of Leeds for my first three years and a scholarship by the School of Computing for my last six months. I am indebted to all participants who took part in my two user studies. They are my heroes. Without them, this research could have never been completed. To all my friends back home in Vietnam, here in Leeds, and somewhere else now, thank you for your care and understanding. You all have made my life more interesting. Last but not least, I would like to thank my family who have always trusted and supported me in whatever I do. - vi - Abstract This research addresses the general topic of “keeping found things found” by investigating difficulties people encounter when revisiting webpages. The overall aim of the research is to design, develop and evaluate a web history tool that addresses these difficulties. An empirical study has been conducted. Participants recorded their web navigation for three months using a Firefox add-on. Each participant then took part in a controlled laboratory experiment, to revisit webpages they had visited neither frequently (on only one day) nor recently (1 week or 1 month ago). Ten underlying causes of failure were discovered. Overall, 61% of the failures occurred when the target page: 1) had originally been accessed via search results; 2) was on a topic a participant often looked at; or 3) was on a known but large website. Based on the findings of the empirical study, a new visualization history tool which supports people in revisiting webpages has been designed and developed as an add-on for Firefox. The tool has two main novel aspects. Firstly, by providing different navigation techniques, it enables users to revisit webpages within their long-term web history. Secondly, the visualization presentation is created based on the user’s navigational paths (even crossing different tabs) rather than the chronology which webpages were visited. Evidence about the benefits of the visualization history tool has been provided through a three month field study. The results showed that such a history tool solved the identified causes of failure and helped participants succeed on 96% of revisiting occasions. They particularly used the tool to revisit webpages which had been visited neither frequently and nor recently. Participants often took only 3 steps to revisit a webpage. Overall, they were satisfied with the tool and rated it 4.1/5.0, and 84% of them wanted to keep using the tool after the evaluation. - vii - Table of Contents Acknowledgements ..................................................................................... v Abstract ....................................................................................................... vi Table of Contents ...................................................................................... vii List of Tables .............................................................................................. xi List of Figures .......................................................................................... xiii List of Pseudo Code .................................................................................. xv Chapter 1. Introduction ...................................................................... 1 1.1 Research questions ...................................................................... 2 1.2 Approach overview ........................................................................ 2 1.3 Contributions ................................................................................. 3 1.4 Thesis outline ................................................................................ 4 Chapter 2. Background ...................................................................... 7 2.1 Definitions ..................................................................................... 7 2.2 How people navigate on the WWW ............................................... 8 2.3 How people revisit information ...................................................... 9 2.3.1 Using explicit web history ................................................. 13 2.3.2 Using automatically recorded web history ........................ 15 2.3.3 Search again from scratch using search engines ............. 19 2.4 Analysis of tools for revisiting ...................................................... 23 2.4.1 List-based ......................................................................... 26 2.4.2 Visualization ..................................................................... 27 2.5 Technologies used in history tools .............................................. 30 2.6 User study methodologies ........................................................... 32 2.6.1 Approaches ...................................................................... 32 2.6.2 Participants ...................................................................... 33 2.6.3 Tasks ........................................................................... 34 2.6.4 Measures ......................................................................... 35 2.7 Discussion ................................................................................... 36 Chapter 3. The logging tool ............................................................. 38 3.1 Requirements .............................................................................. 38 3.2 Design and implementation ......................................................... 39 3.2.1 The tool bar ...................................................................... 41 - viii - 3.2.2 The history editor form ..................................................... 48 3.2.3 The privacy form .............................................................. 48 3.3 Summary ..................................................................................... 49 Chapter 4. The underlying causes of revisit failure ....................... 51 4.1 Method ........................................................................................ 52 4.1.1 Participants ...................................................................... 52 4.1.2 Revisiting experiment ....................................................... 52 4.1.2.1 Target page criteria ............................................ 52 4.1.2.2 Target description and cue generation ............... 53 4.1.2.3 Experiment procedure ........................................ 54 4.2 Results .......................................................................................