Embedding Behavior Modification Strategies into a
Consumer Electronic Device: A Case Study
Jason Nawyn, Stephen S. Intille, and Kent Larson
Massachusetts Institute of Technology
77 Massachusetts Avenue, NE18-4FL
Cambridge, MA 02139
firstname.lastname@example.org; intille | kll @mit.edu
Abstract. Ubiquitous computing technologies create new opportunities for pre-
ventive healthcare researchers to deploy behavior modification strategies out-
side of clinical settings. In this paper, we describe how strategies for motivating
behavior change might be embedded within usage patterns of a typical elec-
tronic device. This interaction model differs substantially from prior approaches
to behavioral modification such as CD-ROMs: sensor-enabled technology can
drive interventions that are timelier, tailored, subtle, and even fun. To explore
these ideas, we developed a prototype system named ViTo. On one level, ViTo
functions as a universal remote control for a home entertainment system. The
interface of this device, however, is designed in such a way that it may unobtru-
sively promote a reduction in the user’s television viewing while encouraging
an increase in the frequency and quantity of non-sedentary activities. The de-
sign of ViTo demonstrates how a variety of behavioral science strategies for
motivating behavior change can be carefully woven into the operation of a
common consumer electronic device. Results of an exploratory evaluation of a
single participant using the system in an instrumented home facility are pre-
The average American watches over 4 hours of television each day . As time spent
in sedentary media consumption increases, the amount physical activity one incurs
typically decreases. This is an unsettling fact of life for many Americans, 50% of
whom feel they presently watch too much television and would like to reduce their
viewing . Meanwhile, rates of obesity have increased markedly in recent decades,
and millions of Americans report engaging in weight-control efforts on a regular basis
. Few people, however, actually succeed in altering their long-term health outlook,
in spite of accumulating evidence of the positive correlation between sedentary be-
havior and obesity  as well as lifestyle-related medical disorders such as Type 2
diabetes . Similar trends are being reported in other industrialized countries.
Successfully reducing the time spent in television viewing over the long term could
produce meaningful gains in an individual’s overall health, especially if this activity is
replaced with less sedentary alternatives. However, television habits are notoriously
difficult to modify, often exhibiting the resilience of chemically based addictions .
The nature of the television viewing experience explains its addictive properties: the
intrinsic rewards of watching television, such as relaxation and passivity are immedi-
ate and self-reinforcing. Unfortunately, these rewards diminish over time, and after
periods of extended use, TV viewers often feel worse than before they started .
In contrast, the goal of increased physical activity is routinely impeded by the per-
ceived high costs of entry into the pursuit. Engaging in exercise is typically thought to
involve getting dressed, going to the gym, working out, showering, and then returning
home. As a further impediment, the rewards of exercise—unlike television viewing—
are not immediate, often to be noticed only months or years down the road. In fact,
the main short-term effects of physical activity may be unpleasant ones, as captured
by the common expression, “no pain, no gain.”
The essential problem is that television viewing is instantaneously rewarding while
exercise is instantaneously aversive. Intervention in this area has proved challenging
in the past because successful behavior modification depends on delivery of motiva-
tional strategies at the precise place and time the behavior occurs. Advances in sen-
sor-enabled mobile computing technologies will now facilitate the creation of applica-
tions that can intervene at critical moments throughout the day. As an exploration of
how ubiquitous computing devices might enable novel approaches to improving life-
style behaviors, we describe a case study with two interrelated objectives: (1) pilot the
use of a novel technology to preempt or disrupt the stimulus-reward cycle of TV
watching and (2) pilot the use of the same novel technology to decrease the costs of
physical activity, while providing immediate positive reinforcement.
1.1 Technology-enabled behavioral modification strategies
This project builds upon prior work relevant to the motivation of lifestyle change.
Knowledge campaigns (e.g. ) and clinical interventions (e.g. ) are the two most
common approaches to the problem thus far. Other than websites and CD-ROMs,
prior efforts at using technology to reduce television viewing have focused primarily
on devices for children. The majority of these served as primitive electronic gatekeep-
ers to limit a child’s access to the TV. Specific examples include a key locking
mechanism and a token access system . These systems use forced rationing or
punishment often imposed by the parents, and therefore they are less likely to be
adopted by adults.
Several technology-related projects have attempted to simultaneously address the
problems of television viewing and inactivity by creating exercise-contingent TV
activation systems. One such system, Telecycle (see ), requires the user to pedal a
stationary bicycle continuously in order to maintain a fully resolved television picture.
While this approach is appealing in concept, it is designed to improve quality of exer-
cise, not to reduce quantity of television viewing. Furthermore, the long-term effec-
tiveness of any intervention that demands physical activity in exchange for television
time should be suspect, since it obstructs a principle objective of television viewing –
Another recent attempt to address the problem of sedentary lifestyle and TV takes
the form of a step-counting insole, Square Eyes , that allows a child to earn a
daily television allowance based on their amount of walking. As in the case of the
Telecycle, this approach effectively uses a short-term goal orientation to reward
physical activity. However, as is the case for many existing television interventions, it
does so by framing television as a conditional reward stimulus, opening up the possi-
bility that it may ultimately increase the user’s motivation to watch TV .
Research into the use of technology to increase physical activity independent of
television viewing is more extensive. The most pervasive use of technologies is for
measuring amount of ambulation and providing open-loop feedback (e.g. ). The
current market proliferation of consumer-grade pedometers provides testament to the
desire and willingness of individuals to adopt technologies that simply and non-
intrusively assist in their quest to become more active. Preliminary research also sug-
gests that more interactive just-in-time feedback such as that provided by the arcade
game Dance Dance Revolution may be successful in producing short-term motivation
for physical activity among otherwise sedentary children .
Another type of technology intervention proposes to motivate physical activity by
mimicking the type of advice (and affect) used by a human personal trainer .
When delivered on a mobile computing device, such an interface may help users
sustain an ongoing activity regimen. For individuals who do not already exercise
regularly, new interventions might consider ways to lower the startup costs by focus-
ing on small increases in physical activity that accumulate over time, rather than more
intense and therefore intimidating regimens. Research suggests that simple body
movements such as standing up, talking, and fidgeting—behaviors related to non-
exercise activity thermogenesis (NEAT) —may account for energy expenditures
of over 300 kcal per day in obese individuals . The intervention described in this
paper builds on this finding by rewarding small activity increases in addition to in-
tense or sustained exercise.
1.2 The opportunity: just-in-time interactions
The technological intervention we present relies on the same behavioral tendencies
that have been proven effective in unmediated communication: that people respond
best to information that is timely, tailored to their situation, often subtle, and easy to
process . Inexpensive sensors and mobile computing devices provide a platform
that enables the achievement of these objectives through the design of an interface
that draws upon behavioral science principles such as suggestion, goal setting, self-
monitoring and conditioning. To provide further design insight into how these strate-
gies might be embedded into consumer technologies, we have developed a prototype
system to address the growing problem of television watching and physical inactivity.
1.3 Case study overview
The physical embodiment of this intervention is a multifunction handheld device
called ViTo. This device, prototyped on a personal digital assistant (PDA) platform, is
intended as a seamless replacement for the user’s existing television remote control. It
has been designed to provide value-adding features not presently available in com-
mercial remote controls. These features, including a graphical interface, built-in pro-
gram listings, access to a media library, integrated activity management, and interac-
tive games, are used to entice users into adopting the persuasive remote control tech-
nology into their TV viewing routines.
Over time, the device deploys a series of behavior change strategies aimed at help-
ing the user make more informed decisions about his or her viewing practices. It at-
tempts to elicit the user’s activity goals and suggest alternatives to TV watching in a
timely manner. In conjunction with wearable acceleration sensors, it also functions as
an electronic personal trainer, both prompting and rewarding physical activity.
A single-user exploratory case study evaluation was designed to test the viability of
the device both as a research tool and as a technology for behavior change. This study
will also be used to prepare for possible longitudinal testing of similar behavior
change devices. The two-phase experimental design allowed assessment of user reac-
tion to a non-persuasive PDA-based remote control as well as the complete ViTo
system. The two main goals of this exercise were: (1) to demonstrate that ubiquitous
computing technologies could measure changes in participant behavior between con-
ditions and (2) to engage user feedback in evaluating the overall design of the device.
The development of technologies that promote behavior change is inevitably subject
to preconceptions of what a “persuasive” technology is and how it will behave. ViTo
would be considered an autogenous technology, one that individuals might choose to
adopt in an effort to change their own attitudes or behaviors . Achieving this
requires overcoming design challenges similar to those proposed for persuasive tech-
nologies to motivate healthy aging : to provide a user experience that is reward-
ing enough for users to engage in regularly over an extended period of time. Toward
this end, we sought to produce a prototype that shows how a consumer device might
provide feedback that may motivate change while avoiding coercion and not relying
on extrinsic justification.
2.1 Grabbing attention without grabbing time
Prior work on behavior change interventions reveals a tendency for these to be either
(1) resource-intensive, often requiring extensive support staff, or (2) time-intensive,
requiring the user to stop everyday activity to focus on relevant tasks. Most controlled
clinical studies fall into the former category, and CD-ROM or web-based tools gener-
ally fall into the latter. For both approaches, the participant must stop what he or she
would otherwise be doing to “receive” the intervention. The most promising CD-
ROMs are engaging with game-like elements, but few are well suited for busy adults
who find it difficult to repeatedly identify blocks of time during which they can focus
on non-essential computer software.
The challenge of grabbing attention without grabbing time is addressed in the cur-
rent project by embedding the intervention into an activity the target user population
is certain to engage in: watching television. Although it may appear counterintuitive
at first, the television remote control itself is an ideal platform upon which to develop
this behavioral intervention. Ninety-four percent of all U.S. homes already contain at
least one television with a remote control . The remote control has become a
central component of the TV viewing experience, and it is partly responsible for the
increase in sedentary behavior associated with television viewing. The remote control
has led to an increase in channel-surfing behavior, which frequently leads to extended
and unplanned viewing .
ViTo is designed to modify the user’s approach to program selection without inter-
fering with the desire to do so remotely. A discussion of the techniques used to ac-
complish this objective is presented in Section 4. Additional strategies designed to
promote physical activity are deployed not only during viewing, but whenever the
user interacts with the device in other operational modes. Unlike interventions pro-
posed in prior work, the device never requests exclusive interaction for more than a
2.2 Sustaining the interaction over time
If a behavior change application is to have a meaningful impact, its outcome should
be sustainable over the course of years. The design of ViTo as a multifunction device
serves to add value that might encourage long-term adoption. With extended use,
however, comes the risk of annoyance. To counter this possibility, content that may
be viewed as paternalistic or authoritarian was rejected in favor of strategies that pro-
mote intrinsic motivation and self-reflection. Wherever possible, elements of fun,
reward, and novelty are used to induce positive affect rather than feelings of guilt.
Overexposure to even the most innocuous of strategies creates further risk for dis-
continuation. Brevity of interaction sequences along with a time-out period between
presentations serves to prevent excessive exposure to ViTo’s persuasive elements.
Because natural usage patterns are likely to vary over time, the behavior change
strategies use by ViTo are intended to be effective even if the user only occasionally
interacts with the device.
2.3 Avoiding the pitfall of coercion
A review of websites, software, and technologies for behavior modification suggests a
tendency for designers to succumb to the temptation of using coercion for motivation.
In some cases, the result is a technology that prevents an activity such as watching
television. In other examples, the user experience approximates the feeling of a medi-
cal professional mildly scolding the user for less-than-optimal compliance. More
ominously, some systems use threats and fear appeals in an effort to motivate users to
change lifestyle behaviors such as diet and exercise.
Particularly for preventive healthcare technologies aimed at users without immedi-
ate medical concerns, the likelihood that users with tolerate coercive devices for long
is questionable. For this reason, the option to produce a device that nags, punishes, or
otherwise inconveniences the user was expressly avoided in the design of ViTo.