Current Projects: Web Naviagtion.
Co-researchers (email):
Saul Greenberg
,
Bruce McKenzie
,
Michael Moyle
, and
Steve Jones
Improving Web Page Revisitation: Analysis, Design, and Evaluation
In this paper, we distill several
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.
Gesture Navigation: An Alternative `Back' for the Future
Web navigation relies heavily on the use of the `back' button to
traverse pages. The traditional back button suffers
from the distance and targeting issues that govern Fitts' Law. An
alternative to the button approach is the use of
marking menus---a gesture based technique shown to improve access times of
commonly repeated tasks. This paper
describes the implementation and evaluation of a gesture-based mechanism
for issuing the back and forward
commands in web navigation. Results show that subjects were able to
navigate significantly faster when using
gestures compared to the normal back button. Furthermore, the subjects
were extremely enthusiastic about the
technique, with many expressing their wish that "all browsers
should support this". Subjective measures also
showed significantly higher ratings for the gesture system over the back
button. Finally, subjects found the `flick'
gesture easy to learn.
Pushing Back: Evaluating a New Behaviour for the Back
and Forward Buttons in Web Browsers
The Back button on web browsers is one of the world's most heavily used
user interface components, yet its
behaviour is commonly misunderstood. This paper describes the evaluation
of a `temporal' alternative to the normal
`stack-based' behaviour of Back and Forward. The main difference of
the temporal scheme is that it maintains a
complete list of previously visited pages. The evaluation compares the
efficiency of the stack and temporal schemes
in an `out of the box' scenario in which the subjects were asked to
use a `new' version of a commercial browser
without any explanation of the presence or absence of new features. This
scenario allows us to predict the likely
usability impact if commercial browsers were released supporting the
temporal scheme. As expected, the results
showed no reliable difference for many standard activities such as
`hub-and-spoke' browsing. Also as expected, the
temporal scheme was reliably slower for multi-level backtracking to
parent pages. Interestingly, however, the
temporal scheme polarized user performance in more complex navigation
activities, with subjects either becoming
very efficient or inefficient. Overall, the results are positive and
indicate that the temporal scheme can be adapted to
improve web navigation.
An Empirical Analysis of Web Use
This paper provides an
empirical characterisation of user actions
at the web browser.
The study is based on an analysis of four months of logged client-side
data that describes user actions with recent versions of Netscape
Navigator.
In particular, the logged data allows us to determine the title, URL and
time of each page visit, how often they visited each page, how long they
spent
at each page, the growth and content of bookmark collections, as well as
a variety of other aspects of user interaction with the web.
The results update and extend prior empirical characterisations of web
use.
Among the results we show that web page revisitation is a much more
prevalent activity than previously reported (approximately 81% of pages
have been previously visited by the user), that most pages are visited
for a
surprisingly short period of time, that users maintain large (and
possibly overwhelming) bookmark collections, and that there is a
marked lack of commonality in the pages visited by different users.
These results have
implications for a wide range of web-based tools including the
interface features provided by web-browsers, the design of caching proxy
servers, and the design of efficient web-sites.
WebView: A Graphical Aid for Revisiting Web Pages
Current commercial web browsers such as Netscape Navigator and
Microsoft Internet Explorer provide a wide and
diverse range of utilities, such as history lists and bookmarks, that
support revisiting previously seen pages on the
web. Yet previous research indicates that these utilities are largely
unused. In this paper, we present an
alternative
utility called WebView; a prototype designed to improve the efficiency
and usability of page revisitation. It does
this by paying particular attention to how previous pages are
represented visually, and by integrating many
revisitation capabilities into a single display space. Our preliminary
evaluation of WebView indicates that users are
enthusiastic about the functionality provided, and that it improves the
efficiency of some navigational acts.
Getting Back to Back:
Alternate Behaviors for a Web Browser's Back Button
This paper concerns the ubiquitous
Back button found in
most Web browsers. First, we outline why Back is an
effective method for revisiting WWW pages: a) It allows
rapid return to very recently visited pages, which comprises
the majority of pages a person wishes to return to; b) People
can use it even with a naïve model of the way it works; c)
People usually keep it on permanent display because it is
visually compact; and d) Back works via a simple 'click
until the desired page is recognized' strategy. Second, we
investigate the behavior of Back. The typical stack-based
behavior underlying Back is problematic because some
previously seen pages are not reachable through it. To get
around this problem, we offer several alternate behaviors of
the Back button, all based upon a recency model. The
advantage of recency is that all previously seen pages are
now available via Back. Because trade-offs exist, we
present both problems and prospects of these different Back
behaviors in various navigational situations.
Which Way Now? Analysing and Easing Inadequacies in WWW
Navigation
This paper examines the usability of the hypertext navigation facilities
provided by World Wide Web client applications. A notation is defined
to represent the user's navigational acts and the resultant system
states.
The notation is used to report potential, or `theoretical,' problems in
the models of
navigation supported by three web client applications. A usability
study
confirms that these problems emerge in actual use, and demonstrates that
incorrect user models of the clients' facilities are common.
A usability analysis identifies inadequacies in the clients' interfaces.
Motivated by the analysis of usability problems, we propose
extensions to the design of WWW client applications. These proposals
are demonstrated by our system WebNet which uses dynamic graphical
overview diagrams to extend the
navigational facilities of conventional World Wide Web client
applications.
Related work on graphical overview diagrams for web navigation is
reviewed.
A review of novel systems for visualising web navigation
Co-researcher (email): Steve Jones
The World Wide Web (WWW) is a successful hypermedia information space
used by millions of people, yet it suffers from many deficiences
and problems in support for navigation around its vast information
space. In this paper (300K pdf) we identify the origins of these navigation
problems, namely WWW page description languages, WWW page
design and WWW browser design. Regardless of their origins, these
problems are eventually represented to the user at the browser's
user interface.
We therefore investigate improvements to browser interfaces that
promise to assist navigation. We identify key issues in the
adoption of such a strategy. These include visualisation of WWW
subspaces, visualisation techniques, visualisation generation,
browser independence and navigation support functions.
We consider and classify existing systems and related work with
respect to these issues.
The identification of these issues and the discussion of exemplar
systems will help to guide future design of WWW navigation tools.
Associated work at Calgary
A paper summarising Linda Tauscher's
quantitative work on page revisitation in WWW.
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