multiple user interfaces cross-platform applications and context-aware interfaces

Multiple User Interfaces Cross-Platform Applications andContext-Aware Interfaces Edited by Ahmed Seffah and Homa Javahery Concordia University, Department of Computer Science, Canada...

Multiple User Interfaces Cross-Platform Applications and

Context-Aware Interfaces

Edited by

Ahmed Seffah and Homa Javahery

Concordia University, Department of Computer Science, Canada

Multiple User Interfaces Cross-Platform Applications and

Context-Aware Interfaces

Edited by

Ahmed Seffah and Homa Javahery

Concordia University, Department of Computer Science, Canada

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Multiple user interfaces : cross-platform applications and context-aware interfaces / edited by

Ahmed Seffah & Homa Javahery.

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ISBN 0-470-85444-8

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Acknowledgements xv

Ahmed Seffah and Homa Javahery

Ahmed Seffah and Homa Javahery

David Thevenin, Jo¨elle Coutaz, and Ga¨elle Calvary

David England and Min Du

4.3.3 Task Management Pattern 61

Constantine Stephanidis, Alexandros Paramythis, Vasilios Zarikas,

and Anthony Savidis

Mir Farooq Ali, Manuel A P´erez-Qui˜nones, and Marc Abrams

6.6 Transformation-Based UI Development Environment 111

PART IV MODEL-BASED DEVELOPMENT 169

Peter Forbrig, Anke Dittmar, and Andreas M¨uller

Jean Vanderdonckt, Elizabeth Furtado, Jo˜ao Jos´e Vasco Furtado,

Quentin Limbourg, Wilker Bezerra Silva, Daniel William Tavares Rodrigues, and Leandro da Silva Taddeo

Luisa Marucci, Fabio Patern`o, and Carmen Santoro

11.2 An Illustrative Scenario 219

Homa Javahery, Ahmed Seffah, Daniel Engelberg, and Daniel Sinnig

Anind K Dey and Gregory D Abowd

13.2.3 Transparent, Distributed Communications 265

Simon Lock and Harry Brignull

14.7.2 Dynamic Device Service Selection 311

Gustav ¨ Oquist, Mikael Goldstein and Didier Chincholle

Charles Denis and Laurent Karsenty

The help of many people made this book possible, and we are grateful to all of them Wethank our editor Birgit Gruber, at John Wiley & Sons Ltd., who guided us throughoutthis project.

Daniel Engelberg and Jonathan Benn were indispensable for the editing process, and

we thank them for their help in editing various chapters Daniel Sinnig patiently helpedwith revising various chapters Rozita Naghshin, our digital art expert, was a great source

of help for advice on image layout and creation To all the members of the HCSE Centered Software Engineering) Group, we thank you for participating in the discussionand brainstorming of this project

(Human-We thank FCAR (Le Fonds qu´eb´ecois de la recherche sur la nature et les technologies),NSERC (National Sciences and Engineering Council of Canada), and the Faculty ofEngineering, Concordia Research Chair programs, for their financial support

We are grateful to all the reviewers of this book We were lucky enough to have awide spectrum of international reviewers, who patiently reviewed all chapters and gave

us crucial feedback We thank John Grundy from the University of Auckland, who gave

us sound advice and feedback for a number of chapters

Above all, we thank the contributors of this book Without them, this book would nothave been possible We thank them for patiently modifying chapters, rewriting passages,and putting up with our requests We acknowledge all of them for their efforts in makingthis book a success

Ahmed Seffah is a professor in the department of Computer Science at Concordia

Uni-versity He is director of the Human-Centered Software Engineering Group and theco-founder of the Concordia Software Usability and Empirical Studies Lab He holds

a PhD in software engineering from the Ecole Centrale de Lyon (France) His researchinterests are at the crossroads between software engineering and Human-Computer Inter-action (HCI), including usability measurement, user interface design, empirical studies

on developer experiences with CASE tools, human-centered software engineering, andpatterns as a vehicle for integrating HCI knowledge in software engineering practices

Dr Seffah is the vice-chair of the IFIP working group on user-centered design ologies During the last 10 years, he has been involved in different projects in NorthAmerica and Europe

method-Homa Javahery is a researcher and project manager with the Human-Centered

Soft-ware Engineering Group, including the Usability and Empirical Studies Lab, in thedepartment of Computer Science at Concordia University She holds a Master’s degree

in Computer Science from Concordia University, and a Bachelor of Science degree fromMcGill University She is combining different design approaches from human sciencesand engineering disciplines to develop a pattern-oriented framework for designing a largevariety of interfaces She has been involved in different collaborative projects at theINRIA Research Institute in Nancy, France and the Daimler-Chrysler Research Institute

in Ulm, Germany

didier.chincholle@era.ericsson.se+46 8 585 303 76

Jo¨elle Coutaz

IIHM Group, CLIPS-IMAG Lab

BP 53, 385 rue de la Bibliotheque

38041 Grenoble Cedex 9France

Joelle.Coutaz@imag.fr+33 4 76 51 48 54

Charles Denis

INTUILABPrologue 1, La Pyr´en´eenne,

BP 27/01, 31312 Lab`ege CedexFrance

denis@intuilab.com

Anind K Dey

Senior Researcher, Intel Research

2150 Shattuck Ave, Suite 1300Berkeley, CA 94704

USAanind@intel-research.net+1-510-495-3012

CEO – RedWhale Software

277 Town & Country Village Palo Alto

CGI Group Inc

1130 Sherbrooke West, 7th floor

Montreal, Quebec H3A 2M8

Mir Farooq Ali

Virginia Technology Institute

Department of Computer Science (0106)

660 McBryde HallBlacksburg, VA 24061USA

mfali@cs.vt.edu1(540) 231 1927

Peter Forbrig

University of RostockDepartment of Computer ScienceAlbert-Einstein-Str 21

D-18051 RostockGermany

pforbrig@informatik.uni-rostock.de

Elizabeth Furtado

Universidade de FortalezaNATI – C´elula EADWashington Soares, 1321Bairo Edson QueirozFortaleza (Cear´a), BR-60455770Brazil

elizabet@unifor.br

Jo˜ao Jos´e Vasco Furtado

Universidade de FortalezaNATI – C´elula EADWashington Soares, 1321Bairo Edson QueirozFortaleza (Cear´a), BR-60455770Brazil

John Grundy

University of AucklandDepartment of Computer SciencePrivate Bag 92019

Auckland

Universit´e catholique de Louvain (UCL)

Information System Unit (ISYS-BCHI)

Institut d’Administration et de Gestion

Joanna McGrenere

University of British ColumbiaDepartment of Computer Science201–2366 Main Mall

Vancouver, BC V6J 2E2Canada

joanna@cs.ubc.ca604-827-5201

Andreas M ¨uller

University of RostockDepartment of Computer ScienceAlbert-Einstein-Str 21

D-18051 RostockGermany

Xray@informatik.uni-rostock.de

Gustav ¨ Oquist

Bollhusgr¨and 7

113 31 StockholmSweden

gustav@stp.ling.uu.se+46 8 739 417 783

Alexandros Paramythis

Foundation for Research andTechnology – HellasInstitute of Computer ScienceScience and Technology Park of CreteHeraklion, Crete

GR – 71110 Greececs@ics.forth.gr+30-810-391741

Fabio Patern`o

ISTI-CNRVia G Moruzzi 1

56100 PisaItalyfabio.paterno@cnuce.cnr.it+39 050 3153066

Manuel P´erez-Qui ˜nones

Virginia Technology Institute

Department of Computer Science (0106)

CEO – RedWhale Software

277 Town & Country Village Palo Alto

Foundation for Research

and Technology – Hellas

Institute of Computer Science

Science and Technology Park of Crete

wilker@unifor.br

Daniel Sinnig

Concordia UniversityDepartment of Computer ScienceFaculty of Engineering

and Computer Science

1455 de Maisonneuve Blvd WestMontreal, Quebec H3G 1M8Canada

+1 514-848-3024

Constantine Stephanidis

Foundation for Researchand Technology – HellasInstitute of Computer ScienceScience and Technology Park ofCrete

Heraklion, Crete, GR – 71110Greece

cs@ics.forth.gr+30-810-391741

Leandro da Silva Taddeo

Universidade de FortalezaNATI – C´elula EADWashington Soares, 1321Bairo Edson QueirozFortaleza (Cear´a), BR-60455770Brazil

taddeo@unifor.br

Daniel William Tavares Rodrigues

Universidade de FortalezaNATI – C´elula EADWashington Soares, 1321Bairo Edson QueirozFortaleza (Cear´a), BR-60455770

Universit´e catholique de Louvain (UCL)

Information System Unit (ISYS-BCHI)

Vasilios Zarikas

Foundation for Researchand Technology – HellasInstitute of Computer ScienceScience and Technology Park of CreteHeraklion, Crete, GR – 71110

Greececs@ics.forth.gr+30-810-391741

Wenjing Zou

University of AucklandDepartment of Computer SciencePrivate Bag 92019

AucklandNew Zealandwenjingzou@hotmail.com+64-9-3737-599 ext 8761

Basic Terminology, Concepts,

and Challenges

Executive Summary and Book

Overview

Ahmed Seffah and Homa Javahery

Human-Centered Software Engineering Group, Department of Computer Science,

Concordia University, Canada

1.1 MOTIVATION

In recent years, a wide variety of computer devices including mobile telephones, personaldigital assistants (PDAs) and pocket PCs has emerged Many existing devices are nowbeing introduced as an alternative to traditional computers Internet-enabled television(WebTV), 3D-interactive platforms with voice capabilities, and electronic whiteboardsattached to desktop machines are among the many examples In addition, we are movingaway from the dominance of the WIMP (Windows, Icons, Mouse, and Pointer) system as

a main metaphor of human-computer interaction Novel interaction styles are emerging.These include web applications where users interact with the content, interactive televisioncontrolled by hand-held remotes, and PDAs with small screens and styli for gesture-basedinteraction

All these variations in devices and interaction styles require changes in design, opment and testing frameworks This book aims to introduce the reader to the currentresearch trends and innovative frameworks being developed to address these changes

devel-Multiple User Interfaces. Edited by A Seffah and H Javahery

 2004 John Wiley & Sons, Ltd ISBN: 0-470-85444-8

1.2 A FEW DEFINITIONS

This book refers to several context-specific terms including:

• Multi-device user interfaces: These allow a user to interact using various kinds of

computers including traditional office desktop, laptop, palmtop, PDA with or withoutkeyboards, and mobile telephone

• Cross-platform user interfaces: These can run on several operating systems including

Windows, Linux and Solaris, if the user interface (UI) code is portable For example,Java runs a virtual machine called JVM, and code is compiled into an intermediateformat known as Java byte code, which is platform independent When Java byte code

is executed within the JVM, the JVM optimizes the code for the particular platform onwhich it is running Microsoft’s latest technology, NET follows the same principles.Code is compiled into Microsoft Intermediate Language (MSIL) and is then executedwithin the NET framework as an application domain

• Mobile versus stationary/fixed user interfaces: A mobile platform gives users seamless

access to information and services even when they are moving Mobile computingincludes a large variety of mobile phones and PDAs, as well as new devices such aswireless MP3 music players, digital cameras and personal health monitors

• Context-aware applications: These refer to the ability of computing devices to detect,

sense, interpret and respond to aspects of a user’s local environment and the computingdevices themselves

• User interface plasticity: The term plasticity is inspired from the property of

mate-rials that expand and contract under natural constraints without breaking, thuspreserving continuous use Applied to HCI, plasticity is the capacity of an inter-active system to withstand variations of contexts of use while preserving usabilityproperties

• Universal user interfaces: These can support a broad range of hardware, software and

network capabilities with the central premise of accommodating users with a variety ofcharacteristics These characteristics include diversity in skills, knowledge, age, gender,disabilities, disabling conditions (mobility, sunlight, noise), literacy levels, cultures,income levels, etc [Hochheiser and Shneiderman 2001]

• Multiple user interfaces (MUI): These provide different views of the same information

and coordinate the services available to users from different computing platforms Bycomputing platform, we refer to a combination of hardware, computing capabilities,operating system and UI toolkit The hardware includes traditional office desktops,laptops, palmtops, mobile telephones, personal digital assistants (PDAs) and interac-tive television In a larger sense, computing platforms include wearable computersand any other real or virtual objects that can interact with the services and informa-tion MUIs can support different types of look-and-feel and offer different interactionstyles These different types of look-and-feel and interaction styles should take intoaccount the constraints of each computing platform while maintaining cross-platformconsistency

1.3 CHALLENGES

Olsen et al [2000], Johnson [1998] and Brewster et al [1998] highlight the design

chal-lenges associated with the small screen size of hand-held devices In comparison todesktop computers, hand-held devices always suffer from a lack of screen real estate.Therefore, new interaction metaphors have to be invented for such devices

Many assumptions about classical stationary applications no longer apply for held devices due to the wide range of possibilities currently available This wide range ofpossibilities is due to hand-held devices having constantly updated capabilities, exploitingadditional features of novel generations of networks, and often being enabled for mobileusers with varying profiles

hand-Furthermore, many web-based UIs adapt to client devices, users and user tasks [seeChapters 8 and 10] This adaptation provides interfaces that run on conventional webbrowsers using HyperText Markup Language (HTML), as well as on wireless PDAs,mobile phones and pagers using Wireless Markup Language (WML) [see Chapter 5] Inaddition, it is important to adapt UIs to different users and user tasks [see Chapters 7and 8] For example, it is necessary to hide “Update” and “Delete” buttons if the user is

a customer or if the user is a staff member performing only information retrieval tasks.Building such interfaces using current web-based system implementation technologies isdifficult and time-consuming, resulting in hard-to-maintain solutions

Universal design is emerging as an approach where user interfaces of an interactiveapplication have to be designed for the widest population of users in different contexts

of use In particular, the multiplicity of parameters dramatically increases the complexity

of the design phase by adding many design options from which to choose In addition,methods for developing UIs do not mesh well with this variety of parameters as they arenot identified and manipulated in a structured way, nor truly considered in the designprocess [see Chapter 10]

1.4 SPECIFIC OBJECTIVES

Even if the software tools for developing a large variety of interfaces on each computingplatform are already available or will be in the near future [Myers 2000], the following arethe major development issues that need to be addressed by both academic and industrialresearchers:

• Building the ability to dynamically respond to changes in the environment such asnetwork connectivity, user’s location, ambient sound and lighting conditions: How can

we adapt the UI to the diversity of computing platforms that exists today? How can

we maintain or adapt the high level of interactivity of the traditional office desktop insmall devices without a keyboard and mouse? How can we make it possible for users

to customize a device? When a single device is customized, how can this customization

be reflected on all of the other devices available to the user?

• Designing for universal usability: What kinds of design methods are needed for ing for diverse users and a large variety of technologies? Are the design techniques for

design-UI modelling suitable for addressing the problems of diversity, cross-platform tency and universal accessibility?

consis-• Checking consistency between versions for guaranteeing seamless interaction acrossmultiple devices: Should we strive for uniformity in the services offered, dialoguestyles and presentation formats, or should we adapt the interfaces to the constraints andcapabilities of each device and/or each context of use? When designing MUIs, what isthe best way to take into account the constraints related to each type of device whileensuring maintainability and cross-platform consistency of interfaces?

• Implementing and maintaining versions of the user interface across multiple devices:

How can we implement and validate a MUI for d devices without writing p programs, training an army of developers in l languages and UI toolkits, and maintaining l*p

architectural models for describing the same UI? Are the content markup languagesadequate for device-independent authoring?

The book also introduces a variety of development frameworks that have been investigatedover the last few years:

• Conceptual and adaptation frameworks for interacting with multiple user interfaces,including visual and awareness metaphors, and specific interaction styles;

• Design frameworks and patterns including widgets, toolkits and tools for multi-devicedevelopment and in particular for mobile devices;

• Application frameworks that use multi-devices or multiple user interfaces, in lar collaborative work environments, distance education systems and remote softwaredeployment systems;

particu-• Validation frameworks including usability techniques for testing multiple user faces, as well as empirical tests and feedback

inter-1.5 AUDIENCE

This book introduces design and development frameworks for multi-device, context-awareand multiple user interface systems These frameworks are valuable to researchers andpractitioners in usability and software engineering, and generally to anyone interested inthe problem of developing and validating multi-devices or cross-platform user interfaces.User interface developers, students and educators can use these frameworks to extend andimprove their HCI methodologies, and to learn techniques for developing and evaluating

a multiple user interface

1.6 OVERVIEW

This book is divided into 6 parts:

Part I discusses “Basic Terminology, Concepts, and Challenges” Following the tive summary, in Chapter 2 Ahmed Seffah and Homa Javahery, the co-editors of this book,

execu-present a broad overview of multiple user interfaces They discuss promising developmentmodels that can facilitate MUI development while increasing cross-platform usability Thischapter is highly speculative and will provide questions for basic research This is a selec-tive list of topics, and not exhaustive The goal is to give researchers and practitioners aglimpse of the most important problems surrounding MUI design and development Theeditors’ opinions expressed in Chapter 2 do not necessarily reflect all of the contributors’ideas Complementary and differing opinions are presented by other contributors in theirown chapters After exploring these first two chapters, the reader should have an increasedawareness of the diversity of computing platforms and devices, a deeper understanding

of the major development challenges and difficulties, and a familiarity with the basicterminology used

Part II is entitled “Adaptation and Context-Aware User Interfaces”, and provides threetraditional but comprehensive perspectives on adaptation and context-aware techniques

David Thevenin et al from the CLIPS-IMAG Laboratory in Grenoble, France, introduce

the novel concept of user interface plasticity in Chapter 3 This chapter also provides agenerous glossary of terms complementing the basic terminology presented in Chapter 2.Chapters 4 and 5 examine two dimensions of multi-interaction and adaptation DavidEngland and Min Du, from Liverpool John Moores University, take a look at the dif-ferent temporal characteristics of platforms that can affect user performance They thenpropose a framework taking into account temporal aspects of interaction in the use ofdifferent devices They describe how the temporal aspects should be incorporated into the

interaction design process In Chapter 5, Constantine Stephanadis et al., from the Institute

of Computer Science of the Foundation for Research and Technology – Hellas, Greece,introduce their framework called PALIO (Personalized Access to Local Information andservices for tourists), focusing on its extensive support for adaptation They demonstratehow PALIO has been successfully used in the development of a real-world context-awareinformation system for tourists using a wide range of devices

Part III is on “Development Technology and Languages” and consists of three

differ-ent XML-based developmdiffer-ent frameworks In Chapter 6, Mir Farooq Ali et al (from the

Virginia Technology Institute and Harmonia Inc.) describe a high level XML-based UserInterface Markup Language (UIML) for the development of cross-platform user interfaces

In Chapter 7, Angel Puerta and Jacob Eisenstein, from RedWhale Software, discuss therationale of XIML, another XML-based language for developing multiple user interfaces

by transforming and refining tasks and UI models These modelling and programming

languages distinguish the concrete aspects of a user interface such as presentation and dialogue from its abstract aspects including the context and the tasks They are consid-

ered by the research community to be a bridge across the gap between the design anddevelopment of user interfaces John Grundy and Wenjing Zou, from the University ofAuckland in New Zealand, go a step further by showing how a UI markup language can

be interfaced with existing programming languages They describe how scripts written intheir device-independent markup language (AUIT) can be embedded in conventional Javaserver pages to provide a single adaptable thin-client interface for web-based systems Atrun-time, AUIT uses a single interface description to automatically provide an interfacefor multiple web devices such as desktop HTML and mobile WML-based systems, whilehighlighting, hiding or disabling the interface elements depending on the current context

Together, these three chapters show how XML-based markup languages, with the help

of model-based techniques, can lead to an advanced framework for the development ofmulti-platform user interfaces

Part IV, on “Model-Based Development”, includes three chapters describing the state

of the art and the needed evolution in model-based development approaches The basicpurpose of model-based approaches is to identify useful abstractions highlighting themain UI aspects that should be considered when designing effective interactive appli-

cations In Chapter 9, Peter Forbrig et al from the University of Rostock, Germany,

present two techniques for task modelling and specification The first technique allowsseparate descriptions of general temporal relations within a task model versus tempo-ral constraints that are imposed by the target platform The second technique helps todistinguish between an abstract interaction and specific representations Using these twotechniques, specific features of devices are specified by XML descriptions In Chapter 10,

Vanderdonckt et al (from the Universit´e Catholique de Louvain, Belgium and

Universi-dade de Fortaleza, Brazil) use several models at different levels in their methodologicalframework for universal design First, the design process is instantiated at a conceptuallevel where a domain expert defines an ontology of concepts, relationships and attributes

of the domain of discourse, including user modelling Then at a logical level, a designerspecifies multiple models based on the previously defined ontology and its allowed rules.The last step consists of using a physical level to develop multiple user interfaces fromthe previously specified models, with design alternatives determined by characteristics inthe user models Fabio Patern`o, the father of CTT (ConcurTaskTrees) notation, and hiscolleagues at ISTI-CNR, Italy, explain in Chapter 11 how the user model can be struc-tured for a MUI In particular, they show how information on user preferences and on themobile versus stationary environment (such as location and surroundings) can be used toadapt a user interface at run-time and at design time

Part V is dedicated to “Architectures, Patterns and Development Toolkits” Homa

Javahery et al from the Human-Centered Software Engineering Group at Concordia

University, discuss in Chapter 12 the role of HCI patterns and software reengineeringtechniques in migrating traditional GUIs to web and mobile user interfaces In Chapter 13,Anind Dey, from Intel Research in California, and Gregory D Abowd, from the Geor-gia Institute of Technology, present the Context Toolkit, an innovative and integrativeinfrastructure for the development of context-aware applications Through the description

of a number of built applications, they discuss a low-level widget abstraction that rors the use of graphical widgets for building graphical user interfaces and a situationabstraction that supports easier and higher-level application development In Chapter 14,Simon Lock from Lancaster University and Harry Brignull from Sussex University, UK,describe a run-time infrastructure including a developer-level framework This infrastruc-ture supports the construction of applications that allow multiple users to interact through

mir-a dynmir-amic set of intermir-action devices

“Evaluation and Social Impacts” are addressed in Part VI In Chapter 15, Gustav ¨Oquist

et al (from Uppsala University in Sweden and Ericsson Research) discuss “Assessing

Usability Across Multiple User Interfaces” They present their practical experiences withstationary versus mobile usability evaluations In particular, they outline four typical con-texts of use that they characterized by monitoring four environmental usability factors By

assessing these factors, it was possible to obtain a profile of how useful a given interfacecan be in a certain context of use The usability profiles for several different interfacesfor input and output are also presented in this chapter, partly to illustrate how usabilitycan be assessed over multiple user interfaces, and partly as an illustration of how differ-ent interfaces have been adapted to mobile environment attributes In Chapter 16, JoannaMcGrenere from the University of British Columbia summarizes her MUI evaluationexperiment combining three usability studies In the first study, McGrenere conducted

a broad-based assessment of 53 users of MS-Word 97 Based on the findings from thisstudy, she developed a first multiple-interface prototype for MS-Word 2000 includingone personalizable interface In the last study, personalization was achieved through theWizard of Oz technique Even if McGrenere’s definition of a multiple user interface isrestrictive compared to the ones proposed in this book, her empirical results are verypromising They demonstrate how users were better able to navigate through the menusand toolbars and learn a multiple-interface prototype

Continuing part VI, Charles Denis and Laurent Karsenty from IntuiLab Inc., argue inchapter 17 that the usability of individual devices is not sufficient: a multi-device system

needs to also be inter-usable They define inter-usability as the ease with which users

transfer what they have learned from previous uses of a service when they access theservice on a new device Based on theoretical considerations and empirical observationsgathered from a study with France Telecom, they propose an analysis grid combining twotypes of continuity, namely knowledge and task, with ergonomic design principles includ-ing consistency, transparency, and dialogue adaptability The concept of inter-usability isvery similar to the concept of horizontal usability introduced in Chapter 2 by the editors.Inter-usability or horizontal usability is a new dimension for studying the usability ofMUIs and multi-device user interfaces

REFERENCES

Brewster, S., Leplˆatre, G and Crease, M (1998) Using Non-Speech Sounds in Mobile

Comput-ing Devices ProceedComput-ings of the First Workshop on Human Computer Interaction with Mobile

Devices, May 21 – 23, 1998, Glasgow, UK.

Hochheiser, H and Shneiderman, B (2001) Universal Usability Statements: Marking the trail for

all users ACM Interactions 8(2), March – April 2001, 16 – 18.

Johnson, P (1998) Usability and Mobility: Interactions on the move Proceedings of the First

Work-shop on Human Computer Interaction With Mobile Devices, May 21 – 23, 1998, Glasgow, UK Myers, B., Hudson, S and Pausch, R (2000) Past, Present, and Future of User Interface Software

Tools ACM Transactions on Computer-Human Interaction, 7, 3 – 28.

Olsen, D., Jefferies, S., Nielsen, T et al (2000) Cross-modal Interaction using XWeb Proceedings

of the 13th Annual ACM Symposium on User Interface Software and Technology, UIST’2000, November 5 – 8, 2000, San Diego, USA.

Multiple User Interfaces: Cross-Platform Applications and

Context-Aware Interfaces

Ahmed Seffah and Homa Javahery

Human-Centered Software Engineering Group, Department of Computer Science,

Concordia University, Canada

2.1 MUI: CHARACTERIZATION AND EVOLUTION

We introduced the concept of “Multiple User Interface” (MUI) at the IHM-HCI 2001

workshop [Seffah et al 2001] Others are also using the term MUI with varying definitions [McGrenere et al 2002; Vanderdonckt and Oger 2001] For the purposes of this book, a

Multiple User Interface is defined as an interactive system that provides:

• access to information and services using different computing platforms;

• multiple views of the same information on these different platforms;

• coordination of the services provided to a single user or a group of users

Each view should take into account the specific capabilities and constraints of thedevice while maintaining cross-platform consistency and universal usability By comput-ing platform, we refer to a combination of computer hardware, an operating system and

Multiple User Interfaces. Edited by A Seffah and H Javahery

 2004 John Wiley & Sons, Ltd ISBN: 0-470-85444-8

a user interface (UI) toolkit Different kinds of computing platforms include traditionaloffice desktops, laptops, palmtops, mobile telephones, personal digital assistants (PDAs),and interactive television A MUI provides multiple views of the same information onthese different platforms and coordinates the services provided to a single user or a group

of users Each view should take into account the specific capabilities and constraints of thedevice while maintaining cross-platform consistency and universal usability The informa-tion and services can reside on a single server or computer, or can be distributed amongindependent and heterogeneous systems The desired views are made available on differ-ent computing platforms via the traditional client/server protocol or a direct peer-to-peeraccess The concept of MUIs is highly promising in a variety of fields, such as cooperativeengineering, e-commerce, on-site equipment maintenance, remote software deployment,contingency management and assistance, as well as distance education and telemedicine

As an example of MUI use, a civil engineer can use a Palm Pilot on PalmOS forgathering data when inspecting a new building He/She can then use a mobile telephone

to add comments, fax, or upload information to the office headquarters Finally, the sameengineer or any other employee can use an office workstation under Windows/Linux toanalyze the data and prepare a final report During this workflow, the engineer inter-acts with the same information and services using different variations of the UI These

variations can support differences in look-and-feel, and to a certain extent, differences in

interaction style The following is a scenario that further clarifies the MUI concept andits use, based on [Ghani 2001]:

You are riding in a car with your colleague who is driving Suddenly, your mobile phone comes on, asking if you can take a video conference call from your team in

Canada to discuss a project on which you are working You take the call and as you

communicate with them via the integrated car video system, you find out that they need one of the spreadsheets you have saved on your laptop, which is in the trunk

of the car Using your wireless technology, you are able to transfer the file to your

PDA, and then send it to your team A few minutes later your team will receive and open your spreadsheet, using an office desktop and you can start discussing options with them once again via your interactive television from your comfortable home.

A MUI includes the following characteristics:

• It allows a user to interact with server-side services and information using differentinteraction/UI styles For example, the civil engineer in our previous example coulduse pen and gestures on a PDA, function keys or single characters on a mobile phone,and a mouse for a desktop computer

• It allows an individual or a group to achieve a sequence of interrelated tasks using ferent devices For example, our civil engineer could use a mobile telephone on the road

dif-to confirm an appointment, a deskdif-top computer dif-to email information about an interview,and a PDA to gather information about the user needs when interviewing stakeholders.Finally, a laptop/desktop computer can be used to synthesize the information and writethe requirements report

Figure 2.1 An example of a MUI.

• It presents features and information that behave the same across platforms, even thougheach platform/device has its specific look-and-feel

• It feels like a variation of a single interface, for different devices with the same bilities

capa-Figure 2.1 shows a MUI for an Internet financial management system The interfaceconsists of three views: desktop, PDA with keyboard, and mobile phone Ideally, fromthe user perspective, these three different interfaces should be as similar as possible.However, this is not realistic because of the capabilities and constraints imposed by eachplatform The MUI here can be seen as a compromise between customized and platform-dependent UIs The effort required to keep all interfaces consistent and to maintain themincreases linearly with the number of interfaces, while the functionality of the underlyingfinancial system is expanding

The MUI provides multiple views of the same model and coordinates the user actionsgathered from different devices/computers The model can reside on a single informationrepository, or can be distributed among independent systems Each view can be seen as

a complete UI for a specific combination of hardware, operating system, and UI toolkit.All these interfaces form a unique and single MUI The list of features, the interactionstyle, and the displayed information and feedback can vary from one platform to another

2.1.1 INTERACTION STYLES

A MUI can support different interaction styles for different computing platforms Thefollowing three styles are commonly used: