ARTICLE IN PRESS

1071-5819/$ - se

doi:10.1016/j.ijh

Int. J. Human-Computer Studies 66 (2008) 833–837

www.elsevier.com/locate/ijhcs

Editorial

Mobile human–computer interaction

ACM defines HCI (human–computer interaction) as‘‘a discipline concerned with the design, evaluation andimplementation of interactive computing systems forhuman use and with the study of major phenomenasurrounding them’’ (Hewett et al., 1992). This definitionpositions mobile HCI as a subarea focusing on one speciesof interactive computing systems—the portable andhandheld computer. The ‘‘major phenomenon surround-ing’’ mobile HCI is naturally the user’s mobility. The user’sagency for physical movement changes the conditions ofinteraction so profoundly that mobility is one of the keychallenges for post-millennium research.

How successful have we been in addressing thischallenge? Have we learned something that others mustknow in order to succeed with their mobile services?Looking back over 10 years of research, it seems thatwe have been unable to produce a body of findings thatare widely applied in design and engineering in thisarea. Mobile prototypes are being developed in specialapplication domains that tend not to refer to work done inthe core of mobile HCI. The lack of valid and actionableresults, methods, and theories may be part of the reasonwhy substantial investments in mobile technologies canfail. The case of WAP (wireless application protocol) inEurope is a good example from the recent past. Academicresearch should not be a slave to the development oftechnology but it should steer efforts across applicationdomains.

Nonetheless, the first 10 years of mobile HCI researchcannot be judged as being a failure. Mobile HCI has been,by and large, a technology-focused enterprise (Kjeldskovand Graham, 2003; York and Pendharkar, 2004)and a model of fruitful industry–academia relationships.Numerous commercial products and services have beenanticipated by academic publications and almost all majormanufacturers and network operators have active researchdivisions that take part in the conferences. Location-basedservices, awareness, remove monitoring, media-capturingand sharing, browsers, online banking, business processes,games, office documents, voice communications, shortmessaging, email, and input interfaces are prime examplesof research areas that have contributed to industry efforts.

e front matter r 2008 Elsevier Ltd. All rights reserved.

cs.2008.10.001

However, the bulk of this work has been local in a sense,specific to the application or setting, without generalizableunderstanding that carries over to new applications andsettings. We need stronger basic science without lettingindustry needs ‘‘off the hook.’’The papers of this special issue break new ground by

bringing into focus the expanding spheres of mobile HCI:from the user interfaces designed for the moving user to theimmediate situations at hand and all the way to the widerand more latently operating social, organizational andcultural contexts. In the end, the core of mobile HCI thatintertwines these spheres is how the users’ actions change

their relation to their contexts, and how this in turn affectsthe use of computers. In other words, the unique aspect ofmobile HCI is the strong influence of the environment—almost to the extent we could talk about human–environment–computer interaction. Mobility is essentiallyabout change, something transforming to something elseas a consequence of a user’s agency—a cycle of actionsthat provide new resources and place constraints for theensuing actions. Mobility is therefore both a limiting as anenabling factor and a couple of the papers in this specialissue reveal.We believe that herein lies the greatest advantage of

mobile technologies over as a platform for HCI. Theyshould not simply be conceived as small or inferior versionsof desktop applications, but they enable a host of newservices that leverage their contexts for the benefit of theuser. The environment is not only a condition for achievingsomething but it can be actively exploited. The fullspectrum of the conditions that are relevant spans thephysiology of joint movement as well as to the sociology ofhuman mobility. Papers in this special issue go all the wayto argue that there are aspects in mobility that simplycannot be isolated and disentangled from the richness ofhuman life.

Overview of the papers

Mobile HCI has been an active area for more thana decade, yet this special issue is the first targeting not

ARTICLE IN PRESSEditorial / Int. J. Human-Computer Studies 66 (2008) 833–837834

all of mobile HCI, but specifically the problems of usermobility and mobile use. We received altogether 44submissions and narrowed down the selection to nineoutstanding papers after two rounds of rigorous reviews.The activities studied in these papers are emblematic ofhow mobile devices are becoming one of the most pervasiveplatforms for HCI. The papers cover studies of teenagersin Japan, train travellers in the UK, older users onthe phone, a rural community in the US and foreignexchange workers in the Middle East; they cover contextsfrom work to schools and homes and trading floors; theydraw from ethnography and communication studies tomathematical modelling, from information systems andcognitive science to urban studies. The diversity of frame-works needed to address mobility in these papers impliesthat we do not have a unifying framework for mobility,and may not have in the future. Instead, the phenomenonis tackled from multiple perspectives that are irreducibleto each other.

In the following paragraphs, we go through the acceptedpapers, starting with papers dealing with techniques formobile interaction.

The fluid and natural interactions enabled by modellingphysics are common in games and are moving into mobilephones. Physics engines have been used in games for manyyears to make movements and interactions more realistic,or alternatively to be able to play with the laws to physicsto create new game play. Mobile phones now have theprocessing power to do some of the same things in theirinteractions. Gestures such as flicking pages to turn themor throwing a scrollbar and seeing it slow down the furtherit scrolls are easy for users to understand and make forplayful and engaging interactions. Many phones now alsoincorporate accelerometers so that the in the future thewhole device could be used to gesture, for example tiltingto zoom or scroll. Eslambolchilar and Murray-Smith(this issue) suggest that techniques such as zooming andscrolling based on dynamic models for mobile phonesare in their infancy, with many techniques hard-codedinto applications, rather than using general models thatcould be applied across the whole interface. One reason forthis is that many interaction designers are not familiar withthe concepts, specification mechanisms and calibrationtools needed to make these techniques work. Eslambolchi-lar and Murray-Smith propose a theoretical frameworkto underpin these dynamic interactions and show how itcan be used to model tilt-based speed-dependent automaticzooming.

Until recently, most mobile devices used a smallkeyboard, or a touchscreen and stylus for input. Thingsare now changing with a new generation of devices basedon touchscreens operated by fingers. The removal of thephysical keyboard allows designers more flexibility to alterthe size and shape of a device and to allow input ondifferent parts of it, for example on the back so that thescreen is not obscured during input. However, it is not clearhow effective users will be at interacting on devices such as

these. It requires them to use fingers, thumbs or two handstogether in different ways, sometimes on the front of thedevice and sometimes on the back. Wobbrock, Myers andAung (this issue) present three detailed studies characteris-ing input using different hand postures on the front andback of devices to show the performance of these differentsurfaces. Their results show that the index finger is goodfor input on the front or back of a device, while the thumbis better on the back than the front. However, the indexfinger is more limited when complex gestures are needed,where it performs better on the front of the device. Thesestudies can help device designers understand how to createmore effective interactions in future devices which mayhave very different form factors to the ones we arecurrently using.There has been a very rapid growth in the use of in-

car navigation devices over recent years. The same isbeginning to happen in the area of pedestrian navigation,with many new mobile phones including GPS receiversand mapping software. This has great potential for allpedestrians, but there may be specific benefits for peoplewith cognitive impairments. Cognitive impairments canaffect navigation skills which are fundamental to travel,community integration and personal independence. Theright technology could help overcome some of theseproblems. Due to their disability, cognitively impairedpeople’s needs and requirements are different and standardnavigation tools are not always suitable, particularly in theway that route following assistance is presented. Fickas,Sohlberg and Hung (this issue) studied a range of differentpresentation methods to discover which was the mosteffective at providing route-following assistance for thisuser group. They studied the use of aerial maps, point ofview maps, and audio and textual directions with a groupof twenty cognitively impaired users. Results showed thatspeech-based directions were the most effective, followedby text prompts. Speech was also given the highestpreference rating by the participants. One reason for thisis that it placed the lowest demand on visual attention,a resource that was required in order to navigate theenvironment. The results of this work may also bebeneficial to designers of general pedestrian navigationtools as route following can be cognitively demanding foreveryone, and reducing the load on visual attention willallow all users to focus on the environment they are movingthrough.Kurniawan (this issue) investigates the use of mobile

phones by older users. The ageing populations of Westernsocieties mean that this group of users is growing innumber so it is important that technology is appropriatelydesigned to meet their needs. In some countries, this grouphas a large disposable income and so could be a big, and asyet untapped, market for mobile phone manufacturers.The design of most mobile phones is aimed at a youngeraudience with the addition of extra features being a keyselling point. These may not be the most important aspectsfor older users who need and use their phones for different

ARTICLE IN PRESSEditorial / Int. J. Human-Computer Studies 66 (2008) 833–837 835

reasons. Kurniawan investigated the issues older peopleface when using mobile phones and then identifiedcharacteristics of an ‘ageing-friendly’ phone. Using a rangeof methods, including interviews with expert users, focusgroups and email questionnaires, usage patterns, problemsand successful phone features were found. Her resultssuggest that key features for older users include: memoryaids (easy to access alarms, appointment reminders), bettervisual displays (stronger backlight, larger text), haptic aids(rubber grips, bigger buttons), features to reduce errors(easy to operate keypad lock to avoid mistaken dialling)and safety features (panic button and caller blacklist).Many of these features exist in phones currently on themarket, but are not all available in any one phone andall of the features are not necessarily as easy to find anduse as they might be. Addressing the issues she identifiedwould be straightforward for manufacturers and couldallow them to increase sales to a new segment of themarket.

Trains, buses, planes and taxis ought to be primecontexts of use for mobile devices. Using mobile deviceswhile travelling is not only common; it is the sellingpoint of business phones and PDAs. There is somethingin the ‘‘betweenness’’ of traveling that is easily seen aspromising for mobile technologies. In their article entitled‘‘Mobile technologies in mobile spaces: Findings fromthe context of train travel,’’ Axtell, Hislop, and Whittaker(this issue) investigate train travellers in the UK. Theirpaper is a strong empirical study revealing the physical,material, technological, social, and organizational compli-cations of interaction during travel. On the one hand,despite owning an arsenal of mobile devices, commutersare not able to do work wherever, whenever, and howeverthey want. At times they have to limit their work tothose tasks where communication is not necessary,and they may have to revert to pens and papers to dothe job. On the other hand, workers are not powerlessin face of resource deprivations, but they exhibit quick-witted local adaptations to overcome constraints; andthey plan and at times discipline themselves to addressthese limitations; in best cases they turn these limitationsto their benefit. Previous work that has looked at thepractices of mobile device use has highlighted the variouskinds of ‘‘work’’ use of mobile devices give rise to—mobilization work to actively ensure resources for use (e.g.,Perry and Brodie, 2005) and multi-device work to manageone’s set of devices (Oulasvirta and Sumari, 2007). Thebroader point that Axtell, Hislop, and Whittaker make isthat users orient not only to the constraints of theirimmediate surroundings; they adapt their practices toorganizational expectations and norms. They concludewith a compelling critique of naive notions of ‘‘context’’;even train travel is no clear-cut, unitary context of use, butusers actively construct conditions for work by adaptinglocal resources to their practices and their devices, yet theyare continuously sensitive to non-present, non-visibledemands.

In their article entitled ‘‘Organisational usability ofmobile computing—volatility and control in mobileforeign-exchange trading’’, Sørensen and Al-Taitoon(this issue) expand on the point that non-visible conditionsshape the use of mobile technology. They trace thelong evolution of technologies of foreign exchangetrading from face-to-face bartering in the Babyloniancivilization to the modern 24-h on-floor and off-premisesparadigm where traders orchestrate their use of phones,pagers, and PDAs. Al-Taitoon and Sørensen study tradersof a Middle East bank who use their mobile devices tomake decisions in face of uncertainty and shifting risk. Onthe one hand, market volatility creates a need for off-premises trading and quick decision making underuncertainty but, on the other, this clashes with the needfor organizational control. Mobile traders need specialtechnical and social skills to cope with this problem. Al-Taitoon and Sørensen present evidence for the claim thatwhat we understand as the usability of a mobile systemdepends critically on balancing individual and organiza-tional control. Here, the strong role of mobile devicesemerges in the context of dynamically switching spheres ofwork and personal identities that demands looser couplingand more discretion.Studies since the turn of the millennium have repeatedly

pointed out the importance of mobile phones in coordina-tion of interpersonal activities and, at a higher level, inthe management of one’s social networks (Katz andAakhus, 2002; Kopomaa, 2000; Ling, 2004). For manyyears now, Japan has been at the forefront of mobileservices. Recently, the country has witnessed a massive leapfrom the use of pagers and SMS to mobile e-mail. In theirarticle entitled ‘‘Kei-Tying teens: using mobile phonee-mail to bond, bridge, and break with social ties—astudy of Japanese adolescents’’ Boase and Kobayashi(this issue) report that Japanese youth not only manageexisting relationships with phones; they use phonesto actively add new contact points to their networks.Japanese adolescents use mobile e-mail to bond andbridge with peers, but not to break ties. These findingsare intriguing not only because they are telling of a recentexpansion in the interpersonal uses of mobile phones,but also as they are telling of how mobile devicesexpand to the territory of social networking sites.Boyd and Ellison (2008) define social networking sites asweb-based services that ‘‘allow individuals to (1) constructa public or semi-public profile within a bounded system,(2) articulate a list of other users with whom they sharea connection, and (3) view and traverse their listof connections and those made by others within thesystem’’. Boase and Kobayashi’s findings bring abouta fascinating idea: that mobile e-mail, although notdesigned for this purpose, can be and is utilized for socialnetworking like activities. Instead of traversing digitalconnections, phones are picked out of pockets to ‘‘digita-lize’’ connections that are created face-to-face. The authorsreport that hallway encounters that are too brief for

ARTICLE IN PRESSEditorial / Int. J. Human-Computer Studies 66 (2008) 833–837836

face-to-face conversations are opportunities to exchangee-mail addresses and connection is maintained by sendingmessages throughout the day. E-mail messages reachrecipients across device boundaries and help maintainingconnection no matter whether one is on or off thedesktop. The authors also report an association betweenthe amount of bridging a user does and the intensityof use: more bridging leads to more use of mobile phones.Mobile e-mail may be a forerunner of what may turn intoWeb 2.0 on mobile phones.

In their article ‘‘Theorizing mobility in communitynetworks’’, Carroll and Rosson (this issue) analyze thepotential of mobile technologies for supporting communitynetworks. Their target community is a rural town of 80,000people located in Appalachian mountains and purposeto facilitate information dissemination, discussion, andcollective activity. Carroll and Rosson’s paper is anexercise in and extension of scenario-based analysis to thespace of mobile services. Scenario-based analysis (Carroll,2000) has been one of the most influential ideas in design-oriented HCI during this decade. As Grudin (personalcommunication) puts it, ‘‘the conundrum of human–computer interaction’’ is that an imaginative person canentertain almost any form of interaction or interface,yet there are hard limits on the use of technology.A designer can presuppose a user who can type with twohands while walking, and a marketing researcher that traincommuters are interested in killing time by watchingadvertisements on their devices. Carroll and Rosson takethe reader by the hand and lead through a process to showhow their framework lends itself to difficult phenomenalike communities and mobility. The authors not onlyelaborate the notion of community for this purpose, butthey draw from theoretical and empirical literature to builda scientific basis for their design choices. They deriveprinciples for wireless community networks and discussthe special nature of mobility. The resulting scenariosshow compelling ways of leveraging the physical worldand proximity of community members. The article has atimely focus since communities and more generally ‘‘socialnetworking’’ is an important ingredient of the Web 2.0movement.

As a starting point for their article, entitled ‘‘Storiedspaces: Cultural accounts of mobility, technology, andenvironmental knowing’’, Brewer and Dourish refer tosociologist John Urry (2000), who has suggested thatmobility rather than society may be the primary animatingmetaphor for the present century. Brewer and Dourishwrite: ‘‘If mobility is culturally shaped, then we must thinkabout mobile technologies not so much as devices thathelp solve problems, but as sites at which social andcultural categories are enacted.’’ By claiming that spaceis also a social product, they go beyond the argumentof Harrison and Dourish (1996) that what we callspace can be understood from the perspective of geometryand experience. Technological representations of spaceare never devoid of perspective, but are always impli-

cated in ways of movement and knowing the world.They argue that cultural logics feature in the collectiveunderstanding of space, and that technologies are notagnostic about conflicts between logics. Brewer andDourish develop this argument further through numerousexamples where they re-interpret context-aware servicesfrom new perspectives of cultural legibility, literacy, andlegitimacy.

References

Axtell, Carolyn., Hislop, Donald., Whittaker, Steve. Mobile technologies

in mobile spaces: Findings from the context of train travel.

International Journal of Human–Computer Studies, this issue

(10.1016/j.ijhcs.2008.07.001).

Boase, Jeffrey., Kobayashi, Tetsuro. Kei-Tying teens: using mobile phone

e-mail to bond, bridge, and break with social ties—a study of Japanese

adolescents. International Journal of Human–Computer Studies, this

issue (doi:10.1016/j.ijhcs.2008.07.004).

Boyd, D.M., Ellison, N.B., 2008. Social network sites: definition, history

and scholarship. Journal of Computer-Mediated Communication 13

(1), 210–230.

Brewer, Johanna., Dourish, Paul. Storied spaces: cultural accounts of

mobility, technology, and environmental knowing. International

Journal of Human–Computer Studies, this issue (doi:10.1016/j.ijhcs.

2008.03.003).

Carroll, John M., Rosson, Mary Beth. Theorizing mobility in community

networks. International Journal of Human–Computer Studies, this

issue (doi:10.1016/j.ijhcs.2008.07.003).

Carroll, J.M., 2000. Making Use: Scenario-Based Design of Human–

Computer Interaction. MIT Press, Cambridge, MA.

Eslambolchilar, Parisa., Murray-Smith, Roderick. Control centric

approach in designing scrolling and zooming user interfaces. Interna-

tional Journal of Human–Computer Studies, this issue (doi:10.1016/

j.ijhcs.2008.07.005).

Fickas, Stephen., Sohlberg, McKay., Hung, Pei-Fang. Route-following

assistance for travelers with cognitive impairments: a comparison of

four prompt modes. International Journal of Human–Computer

Studies, this issue (doi:10.1016/j.ijhcs.2008.07.006).

Harrison, S., Dourish, P., 1996. Re-Place-in Space: The Roles of Place and

Space in Collaborative Systems. In: Proceedings of CHI 1996. ACM

Press, New York, pp. 67–76.

Hewett, T.T., Baecker, R., Card, S., Carey, T., Gasen, J.,

Mantei, M., Perlman, G., Strong, G., Verplank, W., 1992. ACM

SIGCHI Curricula for Human–Computer Interaction. ACM Press,

New York.

Katz, J.E., Aakhus, M.A., 2002. Perpetual Contact: Mobile Communica-

tion, Private Talk, Public Performance. Cambridge University Press,

Cambridge.

Kjeldskov, J., Graham, C., 2003. A review of mobile HCI research

methods. In: Proceedings of Mobile HCI 2003, Lecture Notes in

Computer Science. Springer, Berlin, pp. 317–335.

Kopomaa, T., 2000. The City in Your Pocket: Birth of the Mobile

Information Society. Gaudeamus, Helsinki, Finland.

Kurniawan, Sri. Older people and mobile phones: a multi-method

investigation. International Journal of Human–Computer Studies,

this issue (doi:10.1016/j.ijhcs.2008.03.002).

Ling, R.S., 2004. The Mobile Connection: The Cell Phone’s Impact on

Society. Morgan Kaufmann, Los Altos, CA.

Oulasvirta, A., Sumari, L., 2007. Mobile kits and laptop trays: managing

multiple devices in mobile information work. In: Proceedings of the

CHI 2007. ACM Press, New York, pp. 1127–1136.

Perry, M., Brodie, J., 2005. Virtually connected, practically mobile.

In: Andriesson, E., Vartiainen, M. (Eds.), Mobile Virtual Work:

A New Paradigm. Springer, Berlin, pp. 97–127.

ARTICLE IN PRESSEditorial / Int. J. Human-Computer Studies 66 (2008) 833–837 837

Sørensen, Carsten., Al-Taitoon, Adel. Organisational usability of

mobile computing—volatility and control in mobile foreign exchange

trading. International Journal of Human–Computer Studies, this issue

(doi:10.1016/j.ijhcs.2008.07.002).

Wobbrock, Jacob O., Myers, Brad A., Aung, Htet Htet. The performance

of hand postures in front- and back-of-device interaction for mobile

computing. International Journal of Human–Computer Studies, this

issue (doi:10.1016/j.ijhcs.2008.03.004).

York, J., Pendharkar, P.C., 2004. Human–computer interaction issues for

mobile computing in a variable work context. International Journal of

Human–Computer Studies 60 (5–6), 771–797.

Antti OulasvirtaHelsinki Institute for Information Technology HIIT,

Helsinki University of Technology TKK and University of

Helsinki, Helsinki, Finland

E-mail address: antti.oulasvirta@hiit.fi

Stephen BrewsterDepartment of Computing Science,

University of Glasgow, Glasgow, UK