PageTailor: Reusable End-User Customization
for the Mobile Web
Nilton Bila, Troy Ronda, Iqbal Mohomed, Khai N. Truong and Eyal de Lara
Department of Computer Science, University of Toronto
Toronto, Canada
{nilton, ronda, iq, khai, delara}@cs.toronto.edu
ABSTRACT
Most pages on the Web are designed for the desktop en-
vironment and render poorly on the small screens available
on handheld devices. We introduce Reusable End-User Cus-
tomization (REUC), a technique that lets end users adapt
the layout of Web pages by removing, resizing and mov-
ing page elements. REUC records the user’s customizations
and automatically reapplies them on subsequent visits to the
same page or to other, similar pages, on the same Web site.
We present PageTailor, a REUC prototype based on the Mi-
nimo Web browser that runs on Windows Mobile PDAs. We
show that users can utilize PageTailor to adapt sophisticated
Web sites, such as Amazon, BBC and MSN, for browsing on
a PDA. Moreover, the customizations remain effective for up
to a year, even as the content of pages is updated, and can
be reused across similar pages, limiting the customization
effort required to browse a site.
Categories and Subject Descriptors
C.5.3 [Computer System Implementation]: Microcom-
puters—Portable devices; H.4.3 [Information Systems Ap-
plications]: Communications Applications—Information
browsers; H.5.4 [Information Interfaces And Presenta-
tion]: Hypertext/Hypermedia—User issues
General Terms
Algorithms, Human Factors, Performance, Experimentation
Keywords
Mobile Web, Customization, End-User, Small Screen
1. INTRODUCTION
Today, browsing the Web on a handheld device, such as a
smart phone or a PDA, is an unpleasant experience [20, 21].
Most Web sites are designed for the desktop environment
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and render poorly on the small screens available on hand-
held devices. For example, figures 1(a) and 1(b) show the
homepage of the BBC Web site as it renders on a desktop
computer and a PDA, respectively. The limited screen size
of the PDA causes significant frustration to users as they
have to perform considerable scrolling to locate items of in-
terest on the page or may find it difficult to see content that
has been reduced in size.
Some content providers support handheld devices with
technologies such as WML [34] and cHTML [36], where ei-
ther device-specific or low quality versions of pages are hand-
crafted for display on small screens. Unfortunately, these ap-
proaches incur significant overhead as they require content
providers to maintain multiple versions of their content to
support a plethora of devices. As a result, adoption of these
techniques has been limited to a small set of high-traffic Web
sites that can afford the high cost of hand-tailoring content
for mobile clients; and even then, support is limited to a few
popular devices and content is updated at a lower frequency
than the desktop version of the Web site.
This paper introduces Reusable End-User Customization
(REUC 1), a technique that lets end users adapt the layout
of Web pages to the limited screen size of handheld devices.
REUC lets users remove, resize or move Web page elements
as part of their normal browsing activity. REUC records the
user’s customizations and automatically reapplies them on
subsequent visits to the same page or to other, similar pages,
on the same Web site. REUC supports even pages with
content that is updated regularly, such as in Web portals
and news sites, and requires users to customize only a small
number of pages in order to browse an entire site.
REUC takes advantage of the observation that content
in commercial Web sites tends to be generated from tem-
plates that do not change very often. Content providers
have strong incentives for keeping the structure of their Web
pages consistent because stable page layout provides for a fa-
miliar user experience and promotes Web site branding [18].
We describe PageTailor, a REUC prototype that runs on
Windows Mobile PDAs. We implemented PageTailor as a
plugin for Minimo, the mobile version of the popular Firefox
Web browser. PageTailor is fully self-contained and executes
stand alone on the PDA. It supports dynamic Web pages
with rich JavaScript functionality, as well as pages with con-
tent that is updated regularly. PageTailor allows users to
customize a page incrementally, over multiple sessions, and
can reapply user customizations across pages of the same
site. Figure 1(c) shows a version of the BBC homepage that
1Pronounced reuse.
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was customized with PageTailor by a user interested in news
headlines.
Results from controlled experiments conducted with Page-
Tailor show that users are able to successfully customize so-
phisticated Web pages from five real-world sites: Amazon,
BBC, MSN, eBay, and Flickr. For a large majority of par-
ticipants in our experiments, PageTailor successfully reap-
plies the users’ customizations for at least a month, and in
some cases for over a year. Moreover, PageTailor succeeds
in reapplying the users’ customizations to at least 75% of
other pages which serve the same function in the site. On
average, users take 10 minutes to customize a page; a time
commitment that participants in our experiments deemed
acceptable for customizations that can be reused.
This paper makes four contributions: (i) it describes REUC
a technique that lets end users adapt the layout of Web
pages to the limited screen size of handheld devices; (ii) it
describes PageTailor, a PDA-based REUC prototype which
demonstrates that end-user customization of Web pages is
feasible for popular Internet sites using existing hardware
and software; (iii) it shows that even for the case of pages
with content that changes over time, page layout is stable
enough to support the reapplication of end-user customiza-
tions for a period of a month or longer; and (iv) it shows
that end-user customizations can be successfully reapplied
across pages in the same Web site, thus limiting the number
of pages that a user has to manually customize in order to
browse the site.
The remainder of the paper is organized as follows. Sec-
tion 2 introduces Reusable End-User Customization as a
technique to adapt Web pages for mobile devices. Sec-
tion 3 describes PageTailor a prototype REUC implementa-
tion that runs on a PDA. Section 4 describes the controlled
experiments we conducted to evaluate PageTailor, and Sec-
tion 5 presents the results of this evaluation. Section 6 dis-
cusses related work, and Section 7 concludes the paper.
2. REUSABLE END-USER
CUSTOMIZATION
We introduce Reusable End-User Customization (REUC),
a technique that allows end users to adapt the layout of
Web pages originally designed for the desktop, to the limited
screen size of handheld devices, such as smart phones and
PDAs. In our technique, users customize Web pages on the
mobile device itself, using the same view of the content they
use for regular browsing, by directly manipulating graphical
objects on the screen to move, remove or resize elements
on the page. Under the covers, REUC translates the user’s
customizations into operations that mutate the structure of
the Document Object Model (DOM) [37] of the Web page
being adapted. Thus, users do not require programming
experience nor need to be familiar with the page’s intimate
structure in order to customize it.
The content and layout of modern Web pages is controlled
by a combination of HTML, CSS [35], and client-side scripts
mostly written in JavaScript. Typically, the browser first
renders the static portion of the page based on the HTML
and CSS descriptions, generating a DOM representation of
the page, and then executes any associated JavaScript code
which can dynamically add or reformat page elements. Cus-
tomizations in REUC are done after the page has been fully
rendered by the browser. This approach lets REUC sup-
(a)
(b) (c)
Figure 1: The BBC page as rendered on 1(a) a desk-
top and 1(b) a PDA. The same page is shown in 1(c)
after it has been customized with PageTailor.
port modern commercial Web sites that include sophisti-
cated Web pages whose content is increasingly being con-
trolled by JavaScript.
Because REUC requires user intervention, users are un-
likely to benefit much while they are actively involved in
customizing a Web page, as customization requires them to
perform additional activities that are not directly related to
their main purpose for visiting the page (e.g., restructuring
a news article and then reading it is likely to require more
effort than just reading the article). Instead, users benefit
from their customizations when these customizations are au-
tomatically reapplied on subsequent visits to the same page
or to other similar pages. We expect that REUC will be
most beneficial in support of frequent tasks that involve re-
peated visits to the same Web sites or pages (e.g., reading
news from our favorite site, going over the list of new Jazz
CD releases, checking the weather forecast for city where
we live). Conversely, REUC may be less applicable in the
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