Improving Web Page Revisitation: Analysis, Design, and Evaluation

In this paper, we distill s everal years of our research on understanding and improving how people return to their previously visited web pages. Our motivation is that web page revisitation is one of the most frequent actions in computer use, and consequently any interface improvements in this area—no matter how small—can have a very large effect. We report our findings across five categories of revisitation research: characterisations of user behaviour; system models of navigation and their impact on the user’s understanding; interface methods for increasing the efficiency of the Back button; alternative system models for navigation; and alternative methods for presenting web navigation histories. The behaviour characterisation shows that revisitation is a dominant activity, with an average of four out of five page visits being to previously seen pages. It also shows that the Back button is heavily used, but poorly understood. Three interface strategies for improving web page revisitation are described. The first, a gesture-based mechanism for issuing the frequent Back and Forward commands, addresses low-level interface issues, and is shown to be both popular and effective. The second, a ‘temporal’ behaviour for the Back and Forward buttons, aims to overcome the problems associated with poor understanding of the current behaviour of Back. Although the results do not conclusively show advantages for the temporal behaviour of Back, they strongly suggest that revisitation can be improved by providing temporally ordered lists of previously visited pages. The third interface scheme investigates how next-generation browsers could integrate the current tools for revisitation into a single utility, and how simple visualisation methods can be used to aid users in identifying target pages displayed in miniature. Andy Cockburn is a senior lecturer in the Department of Computer Science at the University of Canterbury, Christchurch, New Zealand. He is the director of the Canterbury Human-Computer Interaction and Multi-Media Laboratory. Saul Greenberg is a full professor in the Department of Computer Science at the University of Calgary, Canada. He is the director of the Grouplab Laboratory for HCI and CSCW. Steve Jones is a senior lecturer in the Department of Computer Science at the University of Waikato, Hamilton, New Zealand. Bruce McKenzie is a software engineer at the Jade Development Centre in Christchurch, New Zealand. Michael Moyle is a software engineer at Allied Telesyn Research in Christchurch, New Zealand. Every day, millions of people worldwide have problems returning to previously visited web pages. These problems often amount to little more than the minor annoyance of finding that a page has ‘disappeared’ off the set accessible with the Back button. Sometimes, however, extensive searching is necessary to return to a page: for example, when the user forgets to bookmark a ‘valuable’ page, and he or she cannot remember how it was originally retrieved. Although the impact of these problems on each individual may be small, it is clear that easing these problems can yield enormous benefits when multiplied across millions of users, and billions of page accesses. Since 1994 we have examined the problems of revisiting web pages, and have designed and evaluated several systems aiming to improve web page revisitation. This paper provides an integration and synthesis of this work, and is presented in the following structure: • User behaviour . We begin by reporting the recent results of a web use log-analysis, which show that revisiting pages is a dominant activity on the web. • System and user models of the current behaviour of the Back button . We describe an easy to repeat experiment to demonstrate that many users misunderstand the rudimentary behaviour of the main interface tool for revisitation—the Back button. We also discuss why, despite this misunderstanding, Back is heavily used. • Improving the efficiency of the Back command . We describe the efficiency limitations of the interface mechanisms used to issue the Back command, and present an evaluation of a gesture-based shortcut (similar to the scheme recently provided in the Opera web browser). • Improving understanding and efficiency of the Back model . W describe an alternative ‘temporal’ behaviour for the Back and Forward buttons, and present the results of its evaluation. • Improving the presentation of revisitation tools . In discussing the implications of the earlier findings, we demonstrate how next-generation web browsers could integrate and enhance the diverse tools for revisitation that are available in current browsers (Back/Forward, bookmarks, and history lists). This work is on-going, and preliminary results are encouraging. USER BEHAVIOUR : WHAT DO WEB USERS DO? Considering that web browsers are among the most widely used computer applications, there has been only modest research into how they are used. In this section, we briefly summarize prior analyses of browsing behaviour, and then describe results from our own recent study of what web users do as they navigate the web.