=Paper=
{{Paper
|id=Vol-198/paper-15
|storemode=property
|title=Design methods and software tools for consistency in multi-channel web applications
|pdfUrl=https://ceur-ws.org/Vol-198/paper14.pdf
|volume=Vol-198
}}
==Design methods and software tools for consistency in multi-channel web applications==
https://ceur-ws.org/Vol-198/paper14.pdf
Proceedings of CHI 2006 Workshop “The Many Faces of Consistency in Cross-Platform Design”
14 Design methods and software tools for consistency
in multi-channel web applications
Charlie Wiecha, IBM T.J. Watson Research Center, Yorktown Heights, N.Y., 10598,
USA, wiecha@us.ibm.com
Rahul Akolkar, IBM T.J. Watson Research Center, Yorktown Heights, N.Y., 10598,
USA, akolkar@us.ibm.com
Rafah Hosn, IBM T.J. Watson Research Center, Yorktown Heights, N.Y., 10598, USA,
rhosn@us.ibm.com
Thomas Ling IBM T.J. Watson Research Center, Yorktown Heights, N.Y., 10598, USA,
ling@us.ibm.com
TV Raman, Google Research, raman@google.com
INTRODUCTION
The desire for ubiquitous access to web applications like online shopping, combined with the coming
of age of speech technology, creates unique challenges as we design for multi-channel interaction.
Usable and cost-effective addition of spoken access to these applications requires:
• Identifying user scenarios that benefit from voice interaction, implying the ability to treat
spoken interaction as a first-class user interface modality; experience shows that simply
speaking the same content as in the visual interface does not deliver usable interfaces.
• High quality speech components that need not be developed on a per application basis and
that deliver a consistent “sound and feel” – often called the speech “persona” – within the
voice channel.
• An application design that reuses many of the programming artifacts used by mainstream
Web developers in delivering visual access, and hence also offers appropriate consistency
across the voice and visual channels.
This paper presents a design and engineering approach to multi-channel applications that supports
both intra-channel consistency and cross-channel consistency. The main innovation is the
introduction of a UI component model allowing for sharing or overriding design decisions as
appropriate to interaction using multiple channels. In this paper we illustrate such an iterative
enablement of a transactional web application with voice interaction – using Amazon.com as a test
case.
CONSISTENCY IN MULTI-CHANNEL APPLICATIONS
We do not assume that the entirety of the business process is supported on each of the interaction
channels. Indeed, an important part of the design process is to determine the desired allocation of
function to each user category and to each interaction channel. Our goal is that interaction should
be consistent both within and across channels. For example, all voice interaction in an application
should collect dates using a common prompt style, recognition vocabulary, and confirmation dialog.
Across channels as different as voice and GUI, even though prompts, grammars, and confirmations
may be specific to voice interaction, the navigation rules for collecting such data may reflect the use
of a consistent design with the visual interface. Consider a linear wizard for collecting individual data
items followed by a confirmation of the aggregate data in one final step. Since Web Application
frameworks factor the implementation of such user tasks into controllers and views, they afford us the
opportunity to re-use navigation controllers across channels, while appropriately customizing the view
layer on a per-modality basis. This leads to cross-channel consistency in the overall user experience.
© 2006 for the individual papers by the papers' authors. Copying permitted for private and
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Proceedings of CHI 2006 Workshop “The Many Faces of Consistency in Cross-Platform Design”
SPEECH ENABLING AMAZON.COM
Our goal was to analyze scenarios of widely used online applications to determine specific user tasks
that are best performed using spoken interaction, and to support those in a manner consistent with
the complementary visual interactions. Amazon.com (http://www.amazon.com) was chosen as the
target application and offers a set of user tasks accessible through web services interfaces thus
readily supporting multi-channel interaction.
To support multi-channel design, we have defined a common programming model for user navigation
in both voice and visual displays. This notation for flow is based on the well-known State Chart
semantics from UML, and is being extended with an XML notation in the W3C Voice Browser
Working Group (SCXML) [2]. State charts avoid some of the common problems of state-transition
networks, for example an exploding number of states for global actions, by supporting both
sequential and parallel (concurrent) flows. Our team is participating in the definition of the SCXML
language, and in addition is contributing an open source implementation of an SCXML interpreter to
Apache [3].
WITHIN-CHANNEL CONSISTENCY
Interactions within the speech-enabled sections of the application are under control of components
implemented using our library of Reusable Dialog Components (RDCs) in Apache[1]. RDCs
encapsulate a recursive MVC design pattern that capture unique aspects of voice interaction, and
help better align the data interfaces amongst the different interaction modalities. Each of a number of
data-type specific Reusable Dialog Components encapsulates the best practices of prompting and
error correction – typically across multiple dialog turns – and corresponds roughly to the unit of
content that a single HTML element would gather in an visual page. Associated with the
implementation of an RDC is a more detailed interaction flow diagram, represented again in a State
Chart XML notation, which drives the dialog management within that component.
An example interaction with the voice-based catalog is:
S: Welcome to the RDC Music Store. Choose a music genre or select one of the V-Store
categories.
U: [silence]
S: Say Today's Deals, Top Sellers, New Releases or choose a genre.
U: New Releases
S: The following titles are available. Please select one of: Thelonious Monk Quartet with John
Coltrane at Carnegie Hall, Amarantine, Confessions on a Dance Floor, At Folsom Prison,
Some Hearts, Born to Run: 30th Anniversary 3-Disc Set, X and Y, Breakaway, Brokeback
Mountain, The Breakthrough.
U: Brokeback Mountain
S: Brokeback Mountain is available for $13.49 You can buy the album, obtain more
information or look up similar titles.
U: Describe album
S: Brokeback Mountain has been released by Verve on November 01 2005. You can buy the
album or look up similar titles.
U: Buy album
S: Brokeback Mountain has been added to your cart
U: View Cart
S: The following titles are in your cart: Brokeback Mountain, Confessions on a Dance Floor.
S: You can proceed to checkout or continue shopping.
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Proceedings of CHI 2006 Workshop “The Many Faces of Consistency in Cross-Platform Design”
ACROSS-CHANNEL CONSISTENCY
SCXML is the programming model both for voice dialogs in RDCs and for dialog flows across
multiple JSP pages in a visual application. The goal is to capture essential navigation patterns and
then allow for their refinement as either visual pages in HTML or voice interaction using the RDC
component library generating VoiceXML. The detailed voice interaction will certainly be different from
the HTML pages –and will typically involve multiple turns of dialog prompting for inputs and correcting
for errors, in order to complete what is a single screen of a visual interface. However, the higher level
task oriented navigation can often remain the same.
An interesting special case is in mobile GUI devices, where the information content at each step of
visual interaction is similar to that observed in voice interaction. The smaller screen size of mobile
devices more closely approximates the information a voice user is able to hear and generate per turn
of dialog. In that case, we have been able to draw SCXML dialog flows once and reuse them across
both visual and voice interaction without further refinement on the voice side – the following screen
shots are from the PDA version of the Amazon voice catalog search described above and were
generated from the same navigation controller in both versions of the application.
Figure 1: PDA version of Amazon.com catalog shopping
We believe the greatest utility of the above technology may be less to achieve a literal reuse of the
same web artifacts (navigation controllers, data models, etc) across multiple channels as it is to allow
for a much more rapid exploration of refinements to any one channel without disrupting the overall
design of the application. When done with our initial catalog search, for example, we felt that the
order fulfillment and tracking tasks (“Where’s My Stuff?” in Amazon) might be even more valuable
over a speech channel than initial order entry. The effort to have experimented with order entry and
then observed its voice characteristics was comparable to that of implementing it over a visual
channel – unlike traditional speech development which may be far more costly. We believe,
therefore, that techniques such as in our approach can now bring iterative voice development, and
hence a practical approach to consistency, within the range of affordable use.
REFERENCES
[1] Reusable Dialog Components at Apache: http://jakarta.apache.org/taglibs/doc/rdc-
doc/intro.html
[2] Working Draft of State Chart XML (SCXML): State Machine Notation for Control Abstraction
1.0: http://www.w3.org/TR/scxml/
[3] Commons SCXML implementation at Apache:
http://jakarta.apache.org/commons/sandbox/scxml/
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