Real-Life Use of Multi-Device Services
Stina Nylander
Swedish Institute of Computer Science
stina.nylander@sics.se
SICS Technical Report T2006:18
2006-12-14
ISSN 1100-3154, ISRN:SICS-T--2006/18-SE
ABSTRACT
computer, or on the bus or on the TV couch using a mobile
device. It also introduces new challenges for users such as
interacting with services in new contexts and learning
several user interfaces for each service. To create a good
user experience of those services it is important that
services and their user interface are adapted to the
capabilities of different devices [12, 15]. No single user
interface will be able to provide good user interaction for all
devices, and no device will be appropriate in all situations.
We have conducted interviews with 22 users of three multidevice services, email and two web communities, to explore
practices, benefits, and problems with using services both
from desktop computers and mobile devices. Participants
reported different usage patterns on different devices,
offering support for adapting services to the capabilities of
devices. The most common usage problems reported
concerned text input and navigation on mobile devices, and
data organization over multiple devices.
Surveys and interviews have been conducted with users to
investigate practices, benefits, and problems with multidevice services to inform design. The selection criteria for
the services were that they had both a desktop and a mobile
version, and that they already had a base of experienced
users.
Author Keywords
Multiple device use, user study, real-life use, mobile
services, mobile devices, adaptation.
ACM Classification Keywords
H.1.2 User/Machine Systems, H.5.2 User Interfaces.
Several interesting issues that help us understand the rules
of using multi-device services and that have implications
for the design of such services have been discovered.
Below, the roles of the various devices will be discussed,
what functionality users choose to use on different devices,
and how context influences user behavior. We will also
discuss how standard desktop use “flows over” to mobile
devices, and the well known problem of text input on
mobile devices.
INTRODUCTION
Many electronic services of today can be accessed from
multiple devices. However, the actual use of multi-device
services has been little studied. We have studied three
services, email and two web communities, all used from
both desktop computers and mobile devices.
The technological development has made mobile devices
powerful enough to support a wide range of services that
are available on desktop computers. The group of people
using the same services from more than one device is
constantly growing, and the services available both from
desktop computers and from mobile devices are increasing
in number, examples are email, Internet banking, and online
communities.
RELATED WORK
This work touches upon two areas of research, one is the
study of multi-device service use, and the other is research
methods for studying mobile use of electronic services.
There are not many studies of multi-device service use.
This is probably due to the fact that, until recently, mobile
technology has been quite new and the research has focused
on exploring its potential. Projects have resulted in design
sketches or mockups rather than working prototypes for
example [10]. Now, the technology is mature enough, but
there is still little work on real-life use of multi-device
services. Järvinen et al. have created the TIVIK system, a
research prototype of a service that provides nutritional
information about various food products based on their
product barcodes [7] and is accessible both from cell phone
and from desktop computer. It is difficult for us to build on
these results since the service was introduced to users for
the purpose of the study and thus only novice use could be
Accessing services from multiple devices gives users more
freedom in choosing when and how to interact with their
services, at work or in the home office using a desktop
1
studied. In the case of the TIVIK system, users also had to
use a specific cell phone model provided by the researchers.
This means that they were not only novice users of the
service, they were also using a mobile device they were not
familiar with. It is also difficult to draw any conclusions
regarding real-life use when users do not have a genuine
motive for using the service.
Other studies of multi-device services focus on the
technical aspects of the system, for example how to route
email to different devices depending on the availability of
the users [9, 11]. These projects have done small, informal
user studies, usually with the project developers as
participants, and report little details. This too fails to
address the research question of this paper.
The other area this study is related to is how to study the
mobile part of service use in real-life settings. The use of
multi-device services takes place in various locations and
contexts and that affects how services are used. Due to the
variations in context it is virtually impossible to even
partially recreate the impact of context on service use in a
research lab. Therefore, laboratory studies are not enough
as empirical grounding for the design of multi-device
services. Mobile use takes place at various locations and is
carried out on small devices which makes it difficult to
capture user actions. A range of methods have been tried:
Self reporting: users themselves supply data to researchers
of their use through logs [3], diaries [13], probes [4] or
other techniques such as Experience Clip where users video
tape each other [6]. This way, researchers can get data from
real-life use without having to be present at the time of use
and thus risking to influence users. The drawback of self
reporting is that reported data often is incomplete due to
memory failure, lack of time, and selective reporting. For
example, sometimes users do not want to report their
failures [6].
Observation: Data from real use in real settings can be
obtained by observing users and document events in various
ways. Observers can participate in users’ activities,
participating observation, or try to be as invisible as
possible, non-participating observation. In some cases,
researchers even have observed users of mobile services
covertly in public places [17]. If observation is not
combined with other methods for gathering data, important
information can be missed, such as motives for certain
observed actions or causes to observed reactions.
Capturing user actions: another way of getting data without
being present as a researcher is to capture user actions by
other means than observation, such as using software that
logs key presses and screen taps [1], recording user
conversation during interaction with the service [14], or
adding extra hardware, for example an audio recorder [16].
The drawback of this kind of techniques is that they often
exclude important context information such as why users
tried a certain action or what the outcome was.
Interviews: asking users about their service use is a good
way to collect data about user motives and user experience.
It is possible to ask open questions and follow up on user
answers and thus get a rich material for research. It is
common to combine the methods described above with
interviews to complement the information from for example
self reporting [3, 6]. The drawback of interviews is that
users do not always give correct information.
For this study, interviews were chosen as method for two
main reasons. First, interviews make it possible both to
collect information about issues relevant for the current
study and to identify questions for future work. Second,
interviews give users the possibility to tell their story about
motives, experiences, and problems using multi-device
services. These two reasons seem extra relevant since the
study of multi-device service use is a new research area. It
is thus important to identify the important research
questions, and to get an understanding of how users
perceive their situation.
THE CASES
The selection of the services studied here has been based on
two main criteria:
1.
They have a desktop version and a mobile version
publicly available.
2. They have an existing base of non-novice users.
The background for these two criteria is that we wanted
services that users have chosen to use on multiple devices
themselves, for personal or professional reasons, and thus
were motivated to use. Therefore, it was not an option to
introduce services to users for the purpose of the study, or
to use a research prototype service. We were also interested
in experienced users to reduce possible novice problems,
and by choosing services users already were using on their
own devices we avoided learning effects.
To avoid results that only reflect the specific use of a single
service, three services that supported the above criteria
were selected. They cover different user groups in terms of
age, Playahead being used mainly by teenagers,
Mötesplatsen mostly by middle aged people, and the email
users, at least for this study, being in their twenties and
thirties (see figure 1). The services are also used for
different purposes; email being work oriented and the other
two being pure leisure services. However, all three services
are communication services.
In this study, a multi-device service is defined as a service
that can be used from more than one type of device
(desktop/laptop computer, PDA, cell phone), but only from
one device at a time. Simultaneous use from more than one
device is not considered, neither is multimodal use.
Email
Email is becoming so pervasive in the industrial world that
it needs no further explanation. For this study it has been
considerer as a “high level service” in the sense that it is the
members can buy t-shirts and other things with the
Playahead logo on. Most of the site functionality is free, but
some features come to a cost.
general email functionality (sending and receiving
messages, organize them in folders, accessing them etc.)
that has been studied, not a particular email software client.
This is due to the fact that many mobile devices come with
a custom email client, and it was not feasible to choose
participants that all used the same mobile device. Moreover,
the focus of the study is not primarily on user interface
issues but more high level issues of service use.
The mobile version, Playmobile, is available both as a
WAP page that can be accessed from any mobile device
that has a WAP browser (http://wap.playahead.com), and as
a java application that can be downloaded to phones that
support java. The functionality of Playmobile is mostly the
communication features of Playahead (chat, messages,
SMS, guest book), but also the search function, and the
friends and enemies lists. It is also possible to buy images
and ring tones to the phone, and to change different settings
of your personal presentation.
Email users participating in the study used various desktop
email clients, and also different mobile devices and mobile
email clients. More than 50% of the participants used two
or more desktop email clients, often in combination with a
web mail account, the most common being MS Outlook and
Mozilla Thunderbird. The most common web mail was
Gmail. Mobile devices ranged from high-end smart phones
(HP Ipaq, Qtek 100 and 200 series, and Treo) to standard
cell phones (Sony Ericsson T630 and K750i, Nokia 6230).
METHOD
Surveys
Mötesplatsen have recently released a mobile beta version
of the web site that gives members access to some of the
functionality: the messaging function, the visitors list, and
their own presentation (however no editing is possible). The
mobile version is implemented as a WAP page and thus
available from any mobile device that runs a WAP browser
(http://mobil.motesplatsen.se). No extra software needs to
be installed.
The data collection was initiated with surveys whose main
purpose was to recruit participants to the upcoming
interviews (i.e. users of both the desktop and the mobile
version), but also to get a general picture of the user group
and the motives behind using multiple devices. The surveys
covered questions about how often the services are used
from a computer and a mobile device, reasons for using the
services from a mobile device, general use of computers
and mobile services, and problems with mobile use. The
surveys were administered as web forms that were
automatically sent to the author by email. A link to the
email survey was spread through the authors’ friends and
colleagues (who were asked to spread it further) and also
advertised at www.idg.se, a forum for computer related
topics. A link to the surveys for MP and PA were advertised
on the respective sites, and mobile users were also
contacted directly through messages on the sites. People
who filled out the survey for any of the three cases were
asked to supply contact information if they were willing to
be interviewed. The email survey yielded 40 responses, the
survey for MP 740, and the PA survey 780. The large
difference in numbers is due to the fact that for MP and PA
it was easy to reach a large number of users in a short time
since they log on to the sites. Finding users of both desktop
and mobile email required extensive search.
Playahead – a community site
Participants
Playahead (PA) is a community web site with a mobile
version
called
Playmobile.
The
website
(www.playahead.com) offers members the possibility to
present themselves with text and pictures, to communicate
through various channels, to search for other members, to
see what is going on and what other members are doing on
the site, and to join teams of members. It is possible to
create and edit lists of friends and enemies, and to see if
people on those lists are online. Each presentation has a
visitors log where members can see who has visited their
presentation, and each member can keep a personal blog.
Other functionality on the web site includes a news
magazine, competitions with prizes, and a shop where
The selection of participants for this study has not been
conducted in a way that ensures that the samples are
representative for the entire user population. In the case of
MP, a link to the survey was displayed on the front page of
the web site during four weekdays and nights, so users that
only logged on to the site during weekends did not see the
call for survey volunteers. For PA the link to the survey was
advertised in short intervals at three times, all during
daytime. In both cases, mobile users have been contacted
directly through messages which yielded a larger
percentage of mobile users among the survey respondents
than in the general user population.
Mötesplatsen – a dating site
Mötesplatsen (MP) is a Swedish dating site for people older
than 18, the name meaning “the meeting place” in Swedish.
It has a web site (www.motesplatsen.se) that provides
members with the possibility to present themselves with
text and pictures, search for members, communicate with
members, see what is going on at the site, and advertise
invitations to social events such as travels, parties, pub
evenings etc. All presentations have a visitors log, where
each member can see the last 30 members who have visited
their presentation. The list of online members shows the
alias of the last 100 that logged in, and a counter shows the
total number of members that are currently logged in. Most
of the functionality is free, but some features come to a
cost.
3
Age
Ge nde r
90%
100%
80%
90%
80%
70%
60%
E mai l
50%
MP
40%
PA
30%
70%
60%
E mai l
50%
MP
40%
PA
30%
20%
20%
10%
10%
0%
15-20
21-30
31-40
41-50
51-60
>60
0%
M en
Figure 1: The age distribution among survey participants.
The surveys show that the case services cover different age
groups. The main age range for email survey participants
was 20-40 years, for MP survey participants the main age
range was 30-50, while PA seem to be a teenage service
with the majority of survey participants younger than 20
years, see figure 1.
The gender differences between the services are less
obvious than the age differences. There is a large majority
of men among the email users that responded to the survey,
which is partly due to selection error. MP and PA are more
similar, with a slight overweight of men among the MP
users that responded to the survey and a slight overweight
of women among the PA users, see figure 2.
The purposes for the surveys were to characterize the users
that accessed each case service from multiple devices, and
to find suitable users to approach for interviews. The main
criterion for selection for interview was frequent service use
both from desktop computer and from a mobile device.
Virtually all the participants that filled in the survey used
their case service daily from a desktop computer.
When possible, participants of both genders and from
different age groups were selected (difficult for email where
almost only men volunteered for interview and for PA
where the majority of users were between 15 and 20 years
old).
Procedure
Semi-structured individual interviews were conducted with
22 participants, seven email users, eight MP users, and
eight PA users. The interviews were made in Swedish and
all interviewed participants were residents of Sweden.
About two thirds of the interviews were made over the
phone due to large geographic distances. An interview form
with open-ended questions was used, and participants were
encouraged to elaborate their answers. Follow-up questions
were asked when needed, as well as clarification questions.
Each interview lasted about 30 minutes.
All interviews were recorded and notes were taken. The
notes have been complemented with material from the
recordings, but no word by word transcription of the
interviews has been done.
W omen
Figure 2. Gender distribution among survey participants.
USAGE PATTERNS
All of the interviewed participants were frequent users of
one of the case services. They all used their service daily
from the desktop computer, and daily or weekly from the
mobile device. Even though it was the same service that
they used from both devices, the usage patterns were
different. Below patterns that were found in the use of all
three case services are presented.
Access and Awareness
In this study, the most important benefit participants
perceived they gained when they could access their services
from mobile devices was to be able to easily check the state
of their message box. They carry their mobile device all the
time, and at any time they can check if any new messages
have arrived. Since the phone is always on and always
connected through GPRS it is a quick and simple operation.
Participants also stated that often they did not want to
interact with their services from a mobile device in the
same way as they do from the desktop computer, but to see
if something has arrived or if they need to take further
action. They wanted to check if they had received email or
other messages, if they needed to answer (which they often
choose to do from the desktop computer) or take any other
action.
E2:17 – It is an advantage to have your email in the phone, you
get it immediately.
MP6:19 – I am curious too, can’t wait. Not logged on long from
the phone, just in and check.
PA5:13 – Then you could check if any messages arrived during
the day.
Nine participants reported that it was not unusual for them
to use their mobile device to check messages although they
had access to a computer. The mobile device provides
quicker access since it is always on (or starts up in seconds)
and always connected, compared to a desktop computer that
might need minutes to start up and connect.
E2:17 – The phone gives quicker overview of if I need to do
anything with my email at all, if I need to start the computer for
example.
E6:11 – Sometimes I choose the phone for my email even though I
have the computer at hand because I don’t feel like starting the
computer only for checking email. with the phone it’s done in a
second. I do it at home too.
principal device. The majority of the participants, but not
everyone, considered the desktop computer as their
principal device for interacting with the case services.
Choosing the desktop computer as the principal device was
often motivated by its advantages in screen size and
interaction possibilities. The principal device was used for
unstructured use (browsing around) in situations that were
not time critical and for more time consuming tasks.
MP2:34 – At home it can happen if the computer is not switched
on, to check if anything has arrived. The phone is on anyway
This suggests that mobile devices add worth besides being a
backup solution to access services when there is no other
computer available. In some situations a cell phone can
outperform a desktop computer by offering quicker and
more convenient access to a service.
MP5:31 – No! That would be much too cumbersome. The nice
thing is to sit down in the evning and check around. Then you
don’t want to fiddle with the phone.
PA users can get audio notification to their cell phones if
they are logged in. It is also possible to get SMS
notifications, which means that they can get notifications
without being logged in.
The mobile devices had different roles, for example a
means to check messages, an inferior copy of the computer,
or a means for doing almost the same thing with the case
services as on the computer.
PA3:7 – You get an SMS with the sender but not what they wrote,
and then you have to check if it is anything exciting
E6:5 – I am more active in the use on the computer, both in terms
of reading, answering, moving around in folders, and deleting. I
use the address book much more on the computer than on the
phone
Two of the prime features of mobile devices are the form
factor which makes it possible for users to carry them
almost everywhere and the connectivity that allows them to
be on-line almost everywhere. The above examples show
how that can give appreciated worth to users although
mobile devices often provide restricted functionality and
limited possibilities of interacting with the service.
MP5:27 – I am more active on the computer, searched and looked
at new profiles which I didn’t on the phone. It was never the point
with the phone for me, too tedious to check presentations.
However, there were users that had the mobile device as the
principal device. One of the participants learned about PA
when she bought her cell phone, since PA was advertised as
a service she could access from the phone. Since she did not
have a desktop computer at home, the phone became her
principal device for accessing PA. She could perform some
tasks, like managing her profile and looking at members’
photo albums, on her work computer or on friends’
computers, but her regular, daily use was from the phone.
Another PA member that used a cell phone as principal
device for PA was approached about an interview but
declined to participate. None of the participants that used
email or MP had the mobile device as principal device.
Different Activities on Different Devices
Seven participants stated that they organized their use in a
way that some tasks were only attended to on the desktop
computer, or that they strongly preferred to attend to them
on the desktop computer and avoided them on the mobile
device if they could. Tasks that require a certain overview,
such as sorting emails into folders or looking at a personal
presentation with text and pictures, were almost exclusively
handled on the desktop computer. Tasks that were
considered as central to the service, such as checking
messages, were handled on both desktop and mobile
devices. Browsing or other more unstructured use (surfing
around) was done on the principal device which was the
desktop computer for most participants but the mobile
device for some of them.
PA7:24 – Since I don’t have a computer the phone is the main
access point.
The principal device was used to access the service in calm
situations when there was no stress or shortage of time.
This was true both when the desktop computer and the
mobile device was the principal device.
E7:6 – I mostly read on the phone, answer only if it would take too
long before I get to a computer. You can’t search on the phone, if
you want to read an older email it takes too long. You just check if
there is anything new and read it. On the computer it’s like an
archive too.
MP5:31 –The nice thing is to sit down in the evening and check
around. Then you don’t want to fiddle with the phone.
MP2:27 – On the phone I only take care of messages. On the
computer I look for new people, maybe check a presentation or so.
Don’t miss that on the phone, I don’t have the time anyway.
MP2:27 – On the phone I only take care of messages. On the
computer I look for new people, maybe check a presentation or so.
Don’t miss that on the phone.
PA4:28 – You just check the guest book. On the phone ti’s only if
you want to see a contribution or write something important. In
school for example. On the computer you can surf around more.
PA7:31 – More focused on the computer. Use the phone more for
chatting; don’t do that on the computer. It happens, but usually I
don’t have the time.
Many participants also reported that they tried to minimize
input on the mobile device since (see the section on input).
Email offered the best illustration of a service where the
desktop version and the mobile version get different roles.
Four of the email participants explicitly considered the
desktop computer as the dominant version and the mobile
device and mobile email as an add-on or a copy with
Using different functionality on different devices as
described above is connected to the capabilities of the
devices and partly explains how a device gets the role of
5
Figure 1: The age distribution among survey participants.
inferior status. This was manifested in that sent email were
almost always stored on the computer and not on the mobile
device, if possible answering emails was postponed until
users got to a computer, emails were automatically deleted
from the phone after two days, and if something in the
email push went wrong all email ended up in the computer.
E1:6 – To the phone only unread mail arrives. As soon as I read
mail on the computer it’s cleared from the Qtek. BUT if Outlook is
running on the computer I don’t get a single email to the Qtek.
E2:6 – Don’t sort in folders on the phone. There is no point since
emails are deleted after two days and only the inbox is pushed to
the phone.
E4:20 – You have to actively set up the phone to be a window you
look at the computer through. You have to be a little careful.
For the MP users the mobile device was basically a means
to check if there were any new messages in the message
box. They wrote few messages from the cell phone,
browsed little and were usually logged in for short times
from the phone. They considered the phone as a
complement to the computer, but they could not imagine
using MP only from the phone.
MP1:20 – It’s not very important to be able to write messages
from the phone. At least it is more important to be able to write. It
is a little ego.
MP5:18 – The point with the phone is to be able to check if there
are any new messages, and if so from whom and read them. That
was the only thing I used.
MP4:27 – If I think I have received a message I check from the
phone. If there is nothing there I log off. On the computer you can
look around a little.
For the PA users too, the cell phone was a means for
checking if there were new messages in the message box or
new contributions in the guest book, but they also wrote
messages and guest book contributions from the phone to a
larger extent than the MP users. To them, the phone was
also a means for passing time and staying in touch with PA
friends through chatting. As the MP users, the majority
considered the phone as a complement to the computer for
using PA and would not like to use PA only from the cell
phone. However, it is interesting to note that PA does have
users that access the service almost exclusively from the
cell phone and consider the phone as the principal PA
device.
PA7:31 – More focused on the computer. Don’t chat much on the
computer, more ”talk” on the phone.
PA6:31 – Chat more with the phone.
PA8:26 – I write guest book contributions from the phone, works
fine. Don’t write as much from the phone, use abbreviations,
that’s a little faster.
The role of the various devices is shaped by the device
capabilities and the service functionality on each device. It
is a good indication on how a service is used on each
device, and what need users express for the devices. For
example, if a service has very limited functionality on a
device, that device gets a restricted role, as in the case of
the mobile version of MP. The mobile version of the
service only offers the message box and the visitors list, and
thus most users only consider the phone as a means to
check messages. They do not express any need for more
mobile functionality since they only use the phone for
checking messages.
Situational and other External Factors
The situations in which participants said they preferred to
access their services from the mobile device could in many
cases be characterized by lack of access to a desktop
computer. However, sometimes discretion, simplicity, or
comfort made participants choose a mobile device even
though they had access to a desktop computer.
Five of the participants had jobs that required a lot of
mobility, both within the city and over longer distances, for
example visiting customers. When away from the office,
they used their mobile device to access their email since
they could not be sure when they would get to a desktop
computer next time. In some situations it would be useless
to bring a laptop computer since the situation would not
allow placing it and using it anyway, for example when
inspecting a construction site.
E1:9 – But I read a lot of email when I am on customer sites.
E3:11 –It would never work with a laptop when I am out visiting
construction sites.
MP2:14 –Was going to Öland for a few days and then I had to get
MP working on the phone. You can’t be logged out for two days, a
lot can happen.
Sometimes participants had access to a desktop computer
but still chose to access their service from a mobile device.
In some cases this was due to the discretion of the mobile
device which made it possible to access email during a
meeting or during a family activity without being too
obvious. In other cases it was considered easier to use the
mobile device than going to the computer, for example wile
lying in bed, watching a movie, or cooking. The mobile
device was also considered as more private and thus better
to use when not wanting to share the service content with
present friends.
E3:9 – In weekends I want to send email discretely. My wife
doesn’t like that I read and answer email all the time.
MP4:20 – In bed, if I’m in bed and want to check if I have a new
message.
MP2:20 – If I want to check when I’m at a friend’s place, then I
prefer the phone rather than borrowing their computer.
Participants reported that their mobile use often was
affected by lack of time, or other activities. When using the
mobile device to access their service they often were in a
hurry and kept the service interaction short. It was also
common that they were involved in some other main
activity and accessed their service quickly “on the side”.
added to the mobile version, which made some of the
participants stop using the service from the cell phone.
Not surprisingly, the participant that only accessed her
service from a mobile device reported the opposite
behavior: when using the desktop computer she usually had
little time while she could devote more time to the service
from the cell phone.
PA5:27 – I have stopped using PA completely after the free
introduction month. Cost matters.
USAGE PROBLEMS
MP2:27 – On the phone I only log in and check quickly, often I
don’t have the time anyway. Maybe just a couple of free minutes.
When you’re sitting by the computer you have more time.
Input on Mobile Devices – Still not Solved
It is not possible to discuss mobile use of almost any
service without addressing the input issue. Text input has
been a difficult problem to solve through the history of
mobile and ubiquitous computing, and the research
community is always working on new techniques to
simplify text input [2, 8, 18]. The form factor of mobile
devices restrict the text input means to small keyboards
(e.g. Treo, P900), even smaller soft keyboards with thin
styluses (Qtek 110, hp), or the standard multi-tap or word
prediction models for text input on the numeric keypads of
cell phones. This is probably one of the main reasons for
text input still being difficult for most users.
MP4:27 – Often when I log in from the phone I am doing
something else, for example working, and then I don’t want to put
a lot of time on MP. When I want to put more time on MP I do it
on the computer.
PA7:40 – I mostly use PA on the phone to chat, don’t do that on
the computer. Seldom, don’t have the time. Maybe it would have
been different if I had a computer at home.
None of the participants expressed any problem accessing
their services in public. They did not mind if anyone would
see what they were doing and pointed out that it is very
difficult to see what anyone else is doing on a small device
such as a cell phone. None of the interviewed handled any
confidential information in the studied services. Nor did
they worry about what other people would think if they saw
them using their mobile device in public. They stated that
since it is virtually impossible to see what someone is doing
with their cell phone they might just as well be sending an
SMS, which everyone does publicly in Sweden.
Eleven of the interviewed in this study found input on
mobile devices slow and tedious, and preferred to use the
desktop computer with its standard keyboard for tasks that
require text input. If possible, they postponed writing
messages or taking notes until they got to a desktop
computer, and if they had to write on the mobile device
they kept it short.
E7:10 – No problem with reading mail in public, the screen is so
small nobody can read above my shoulder.
E1:5 – I answer shorter from the phone. Writing is slow so you
keep it very short. Picking on the screen.
MP10:21 – Doesn’t bother me the slightest if anyone would see.
MP4:22 – No. I seldom write from the phone, and when I do it’s
short and simple messages.
PA7:25 –Public places don’t bother me. People can look, no
problem.
PA3:20 – I think it’s so tedious to write on the phone, and my
phone is designed for easy writing. But I think it’s slow. Maybe I
haven’t understood how to do yet...
An external factor that many participants brought up
themselves as affecting their use of the case services was
cost. All participants that paid their cell phone costs
themselves (18 people) were aware of the associated costs.
Some of them had flat rate for data transfer and therefore
did not feel any need to limit their service use.
However, some of the interviewed, mostly PA users, had no
problem with entering text from their mobile device, not
even in real-time situations like chatting. Extensive training
was probably a key to this. Users who have had access to
cell phones and text messaging for a long time are much
habituated to text input on cell phones. They have no
problem with writing longer messages than 160 characters
from their cell phones and they do not think that it is too
slow, even though they admit that a standard keyboard is
faster. It seems like age differences are important here, the
majority of those who found text input on mobile devices
easy were younger than 25.
MP6:21 – I have flat rate for data traffic so it is not a problem.
Pay a fixed monthly sum
MP2:21 – No big deal, Telia has a ceiling, 9 SEK a day, but the
amounts of data are small and you pay for the amount. I’m often
surprised when the bill comes.
PA7:25 – With Tre, PA costs 30 SEK a month and that’s ok. If it
was more expensive I don’t think I would pay. So it does matter.
Six participants tried to keep the data transfer to a
minimum.
MP9:25 – Sometimes it’s almost easier to write on the phone.
Either way is fast. Doesn’t matter at all. It’s just that the phone is
smaller and you don’t see everything at once.
E4:12 – I have no problem writing long messages on the phone,
it’s the cost that makes me want to keep it short and that’s not
about text but about attached files.
PA5:26 – I write from the phone, but it takes longer. No problem
writing from the phone, it’s like SMS.
PA4:29 – It works fine. I don’t think it’s any trouble writing on the
phone.
Three of the PA users completely changed their mobile user
behavior when the price of the service changed. In the
beginning the mobile version of PA was free, so users only
paid for data transfer. During the spring 2006 a fee was
7
The difference between the “text entry experts” and the rest
of the participants can be summarized in that the former
group said that text input on mobile devices was ”no
problem, it is like writing an SMS”, while the latter said it
was ”slow and difficult, it is like writing an SMS”.
though, that it would be faster to chat using a standard
keyboard.
PA6:31 – I chat more through the phone than on the computer.
PA7:31 – I don’t chat very much on the computer. More ”talk” on
the phone.
Standard use “flows over” to mobile use
Even though functionality on mobile devices is restricted
for the services in this study compared to functionality on
desktop computers, the desktop use “flows over” to the
mobile devices. Functionality that is frequently used on
desktop computers but are not supported on mobile devices
can cause problems in the mobile use in other ways than
just being missing. A good example of this is email with
attached documents. High end mobile devices can open MS
Word and PDF documents but most of today’s mobile
devices cannot. Even the devices that can open documents
usually work with low bandwidth so downloading attached
documents get slow. However, it is so common to attach
documents to emails that it is almost impossible to offer
mobile email without handling them in some way. This
does not mean that all mobile devices should be able to
open MS Word and PDF documents, but it is important to
look at smooth ways to handle attached documents. For
example allow for downloading the email but not the
attached document to save time and money for the user.
IMAP provides this, but also requires a server that supports
it.
E4:6 – Attached files are downloaded if you want to read the
email. It takes for ever, it’s expensive, and it’s totally pointless
since you can’t open the file anyway. So you avoid it if you can.
E5:6 – Only mobile email? No, since people often attach large
files, like images and pdf files.
E6:6 – Attached files don’t work very well, most of the time my
phone can’t open them. But I attach pictures as a way of
transferring them to the computer.
Usage patterns from the desktop computer can sometimes
be wanted on the mobile device. One participant used an
email client on his desktop that did not support folders.
Instead he managed his email for example through
searching, functionality that he missed on his mobile email.
E7:5 – I search a lot over all.
E7:15 –I would like to be able to search email in a smart way, for
example getting all emails from a sender, or easily open an email
thread.
The other way around, functionality that is frequently used
on desktop computer but does not seem smooth to use on
mobile devices (for example live chatting) can get popular
on mobile devices. Several participants reported that they
chat more on the mobile device than on the desktop
computer. For a user that is skilled in text input on the cell
phone, the chatting on a mobile device works well enough
and offers a possibility to communicate in situations where
the desktop computer is not an alternative. They do admit,
Overview and navigation
Mobile devices have small screens and thus it is sometimes
difficult to get an overview of service functionality or the
service state compared to a desktop screen. Participants
stated that they found it difficult to compose longer
messages on mobile devices since it is difficult to see how
the paragraphs will look on a larger screen. They also found
that they got an immediate impression of the service and its
functionality on the desktop screen since there is more
space to present links and information, while a lot of
navigation was required to obtain the same impression on a
mobile device.
E2:12 – Difficult to get an overview of how a longer email will
look on the computer on the small screen, if you want to make
different paragraphs.
E6:16 – On the phone you first check what has arrived, then open
and scroll to see what it is about. On the computer you more get
everything at once.
PA7:35 – You get a better general impression on the computer.
When you open the site and you have everything there. No clicking
needed.
Due to the limited screen space of mobile devices, more
navigation steps are often needed to access functionality or
information. While it could be possible to display a list of
online members, the message box, and site news
simultaneously on a desktop screen, a mobile device has to
resort to presenting links to the same functionality.
Participants reported that it was slow and cumbersome to
get to what they wanted, too many navigation steps
compared to the desktop computer.
Organization over multiple devices
It is not always easy to get started with a new service, and
this is true for multi-device services too. In some cases a lot
of time and work must be invested to make things work.
Email participants reported that they often had problems to
get started with email on the mobile device, sometimes
having to resort to the telephone support of their cell phone
carrier. Some of them reported being technically advanced
users, for example email admin at work, which gives them
knowledge and access to information that is not available
for regular users. They also more or less expected a little
startup trouble.
E1:12 – By now you don’t expect anything to work from the start.
However, the difficulties were not over when the email was
working. Even though email is a server-based service which
should make access from different devices easy,
participants stated that they invested quite a lot of effort in
purpose for each device when using a multi-device service.
There are several reasons behind the differences in usage
and purpose.
organizing different aspects of their email in a way that
would work with multiple devices. Sent email, deleted
email, and marking of messages as read or unread were
reoccurring issues. Where to store sent mail was an issue
that participants using their mobile device to send a lot of
mail had trouble finding a suitable solution for. If storing all
sent email on the server or on the desktop computer it was
difficult to access them from the mobile device since it is
virtually impossible to synchronize all sent email to the
mobile device due to limited space. Storing messages sent
from the mobile device locally caused problems when there
was a need to access those messages from another device.
None of the participants that brought this up had been able
to set this up in a way that all sent email were available
from the desktop computer, and the messages sent from the
mobile device were also locally available. Deleting
messages from the inbox on the mobile device was brought
up as both an advantage, deleting spam directly, and as a
problem, messages deleted from the mobile device were not
saved in the trash folder on the mail server.
First, various devices provide different capabilities and
advantages, which is an important factor when users decide
how to interact with their services. Mobile devices are easy
to keep at hand and can quickly provide state information
about a service. Desktop computers have screen real estate
that gives good overview and support more visual tasks,
and offers easy input trough standard keyboards and mice.
Device capabilities also control what functionality it is
technically possible to provide on a device. Participants of
this study often stated that they preferred the desktop
computer for browsing and organization tasks, while the
mobile device provided quick access. Further support for
differentiating functionality on devices with different
capabilities can be found in [5] where Hutchings & Pierce
asked users to divide the functionality of services over
several devices used simultaneously. They found that users
divided user interfaces over devices mainly based on the
devices’ I/O capabilities.
E3:15 – It would also be good if some of the sent mail was
accessible from the phone, maybe the two most recent messages.
Now there is no sent mail on the phone..
Second, the usage context highly affects service use.
Mobile use of services makes it possible to access services
in new places and new situations where desktop computers
cannot be used. This also means that services are used
under different circumstances than the traditional desktop
office settings. Participants of this study reported on for
example the amount of available time or attention,
accessibility, and cost as factors that influenced their choice
of device and what functionality they chose to use in a
given situation. Interestingly enough, participants expressed
very few concerns for privacy. They did not mind using
their services in public.
E6:6 – I don’t delete email from the phone, because if I do they
disappear from the server and cannot be accessed from the
computer anymore.
Participants that synchronized their email manually
sometimes complained that messages read on the mobile
device were not marked as read when checking email on the
desktop computer later. If messages were downloaded and
read on the mobile device, but the network connection was
broken before the inboxes were synchronized, messages
read on the mobile device appeared as unread on the server.
Both MP and PA are web based services with no data
stored locally on any device, which reduces the amount of
work for organizing them on multiple devices to a
minimum. However, some PA users report that guest book
contributions that are read from the mobile device were still
marked as new if they later logged on from the desktop
computer. Most of the participants report no problems with
setting up their mobile devices to surf the Internet, which
indicates that cell phone carriers are getting good at
supplying the needed information in an easily accessible
way (SMS being the most common way of getting Internet
settings to a cell phone in Sweden).
This suggests that design of services for multiple devices
should not aim for the same functionality on all devices
since the needs and uses are different for the various
devices. Instead it is important to take advantage of the
strengths of each device. Mobile devices cannot compete
with desktop computers in displaying data or providing
overview, but they offer for example small form factor and
means for notification.
Third, the usability of the mobile versions of the case
services was another factor influencing the usage. Many
participants reported that usability issues made them avoid
some tasks on the mobile device. Most notably, text input
was considered to be slow and tedious but navigation also
caused problems. The issues of input and navigation on
small devices are certainly not new, but they need to be
raised in the context of multi-device services. Since they are
used on both desktop computers and mobile devices it can
be tempting to squeeze too much functionality into the
mobile version to make it as similar as possible to the
desktop version. Most existing multi-device services also
started out as desktop services and thus was not originally
designed for small devices.
MP1:15 – I had already surfed from the phone so all settings were
there. Did it my self, no problem.
PA2:19 – No problem, made it myself.
PA5:19 – The Internet settings were difficult, we had to do it
manually because it didn’t work. My sister had to help me.
DISCUSSION
The findings presented above show that the use of a multidevice service is different on different devices. It has also
been shown above that users do not have exactly the same
9
CONCLUSIONS
We have presented a study on service use from multiple
devices based on three case services: email and two web
communities. Interviews have been conducted with 22 users
to further investigate practices, problems, and benefits with
use of multi-device services.
Participants reported increased accessibility as the main
benefit with multi-device services, especially the possibility
of easy access to information about service state using a
mobile device (e.g. are there any new messages). Moreover,
service use was different on different devices. Participants
preferred to perform tasks like browsing and organizing on
desktop computers, while they often used mobile devices to
check messages since they are quick to start. This suggests
that services should be able to adapt to the capabilities of
different devices.
The main problems with using a service from multiple
devices that have been identified in this study concerns how
to manage a service on more than one device, data
organization over multiple devices and overflow, and
usability on mobile devices, text input and navigation.
Service use from multiple devices is becoming a reality. We
need to learn to design for it, and take advantage of the
special capabilities of each device.
ACKNOWLEDGMENTS
The author would like to thank Jarmo Laaksolahti, Martin
Svensson, Marie Sjölinder, and Markus Bylund for very
helpful comments on this paper.
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