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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>Workshops, Los Angeles, USA, March</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Tamagotchi++: A Serious, Personalized Game to Encourage Healthy Behavior</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Bruce Ferwerda</string-name>
          <email>bruce.ferwerda@ju.se</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Michael J. Lee</string-name>
          <email>mjlee@njit.edu</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Computer Science and Informatics, Jönköping University</institution>
          ,
          <addr-line>Jönköping</addr-line>
          ,
          <country country="SE">Sweden</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Department of Informatics, New Jersey Institute of Technology</institution>
          ,
          <addr-line>Newark, New Jersey</addr-line>
          ,
          <country country="US">USA</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2019</year>
      </pub-date>
      <volume>20</volume>
      <issue>2019</issue>
      <abstract>
        <p>With life expectancy steadily increasing, healthy aging is becoming more important. Especially at a later age, the susceptibility to complications, such as morbidity, increases. Engaging in suficient physical activities throughout a lifespan lowers the chances on such complications and contributes to an increased quality of life. However, the vast majority of the world's population does not engage enough in any form of physical activity. In this position paper we propose a serious game solution to promote physical activities based on the popular Tamagotchi from the 90's. We propose the virtual character of which the user needs to take care of to be a relfection of oneself. Thereby, any (in)activities of the user is directly reflected through the emotional and physical state of the character. Through the character, we hope to increase engagement in physical activities and facilitate long term behavioral change. Furthermore, we propose additional features and open research questions.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>CCS CONCEPTS</title>
      <p>• Applied computing → Consumer health; Computer games; •
Human-centered computing → User models.</p>
    </sec>
    <sec id="sec-2">
      <title>INTRODUCTION</title>
      <p>
        Physical inactivity is known to be one of the leading risk factors for
death worldwide. Engaging in physical activities (PA) 1 has shown
to have many beneficial efects, such as maintaining weight,
improving mental health, and lowering the risk of noncommunicable
diseases (e.g., diabetes, certain types of cancer, and cardiovascular
diseases) [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ]. For people facing impairments, PA can help to
improve their quality of life by improving the ability to do activities of
1PA does not only entail conventional exercises (e.g., aerobics, strength training,
and flexibility workouts), but include any type of bodily movement that results in
energy expenditure, including activities during leisure time, such as walking and
travelling [
        <xref ref-type="bibr" rid="ref49">49</xref>
        ].
      </p>
      <p>
        IUI Workshops’19, March 20, 2019, Los Angeles, USA
Copyright © 2019 for the individual papers by the papers’ authors. Copying permitted
for private and academic purposes. This volume is published and copyrighted by its
editors.
daily living [
        <xref ref-type="bibr" rid="ref21">21</xref>
        ]. However, estimations of the World Health
Organization (WHO) show that more than 80% of the world’s adolescent
population and more than 23% of the adults worldwide engage
insuficiently in any form of PA despite the policies that are in place
to address insuficient PA [
        <xref ref-type="bibr" rid="ref49">49</xref>
        ].
      </p>
      <p>
        The lack of engaging in bodily movements and energy
expenditure are in part due to inaction during leisure time, sedentary
behaviors (i.e., during work and at home), and the increased quality
of public services (e.g., the availability of passive modes of
transportation). These factors are often related to demographic factors,
such as a high or rising wealth of a country [
        <xref ref-type="bibr" rid="ref49">49</xref>
        ]. With countries
becoming wealthier, the availability of technologies in people’s
lives become more prevalent as well. As a result, technologies are
becoming increasingly pervasive and ubiquitous. Estimates show
that currently almost 70% of the population owns some kind of
smart device (e.g., smart phone, smart watch, tablet), with up to 90%
in the more advanced markets [
        <xref ref-type="bibr" rid="ref32">32</xref>
        ]. The widespread adoption of
technologies allow for the creation of technical solutions to support
the aims of promoting PA.
      </p>
      <p>
        In addition to demographic factors, PA is influenced by
intrapersonal determinants, such as perceived behavioral control,
selfeficacy, and self-motivation (see for an overview [
        <xref ref-type="bibr" rid="ref46">46</xref>
        ]). Therefore,
physical inactivity on an individual level is often caused by
psychological barriers. The consequential risks of inactivity may cause
a negative vicious cycle, which leads to further limitation of
bodily movements and energy expenditure and may further increase
health complications [
        <xref ref-type="bibr" rid="ref37">37</xref>
        ]. Although interventions that involve
multiple in-person coaching sessions is a possibility, they are costly and
labor-intensive. Exploiting the widespread adoption of technologies
to support and promote PA may be a better alternative.
      </p>
      <p>
        With the increasing prevalence of smart devices and the
abundance of sensors that these devices consist of, it is now possible
to gain accurate activity data of individuals passively, in real-time.
In conjunction with the increased capabilities of devices, an
increased number of applications promoting PA are available (see for
an overview [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]). However, Bardus et al. [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] pointed out in their
overview that PA applications miss experimental validation on the
eficacy of features on PA, are found to be inefective in increasing
PA over time, and mostly adhere to a one-size-fits-all approach.
      </p>
      <p>
        To increase the efectiveness of PA applications, researchers have
proposed numerous solutions, especially in the form of
gamification (see for an overview [
        <xref ref-type="bibr" rid="ref35">35</xref>
        ]). These applications utilize gaming
elements to encourage people into certain PA by increasing
engagement through entertainment. However, one of the hidden dangers
of entertainment games is that the extrinsic motivations (e.g.,
winning) may become more important than the intrinsic motivations
(e.g., healthier lifestyle) [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. As the extrinsic motivations may gain
the upper hand, the educational aspect may diminish. An
alternative to games for entertainment is serious games. Serious games are
used with the intention to educate or train people [
        <xref ref-type="bibr" rid="ref31">31</xref>
        ]. Training
differs from educating in that the former focuses on the development
of specific identified skills (i.e., for a specific purpose), whereas the
latter contributes to the more general levels of understanding (e.g.,
areas of applications) [
        <xref ref-type="bibr" rid="ref44">44</xref>
        ].
      </p>
      <p>
        The scope of serious games within the domains of health and
welfare is limited. Wattanasoontorn et al. [
        <xref ref-type="bibr" rid="ref48">48</xref>
        ] surveyed the use of
serious games and found that they have mainly been used to either
train people (e.g., improving balance or cognitive functioning) or to
educate people (e.g., educate about healthier lifestyles), but rarely
both at the same time. Creating games in isolation of these aspects
may cause limitations: only covering the training aspect may limit
awareness (e.g., the efects of the skill on health and the breadth of
the area in which the acquired skill can be applied to), whereas only
focusing on the education may limit the efectiveness as there is no
proper training of a skill. Therefore, to maximize the potential of
serious games to promote PA, a game should not only try to train
users with a certain skill, but also educate them about the efects of
the training on physical and mental health, and how the acquired
skill can be incorporated in diferent contexts of daily living.
      </p>
      <p>In this position paper we propose a serious game that facilitates
both training and educational aspects of health interventions. By
incorporating both aspects into one system, we hope to be able to
facilitate long-term behavioral change.
2
2.1</p>
    </sec>
    <sec id="sec-3">
      <title>RELATED WORK</title>
    </sec>
    <sec id="sec-4">
      <title>Physical Inactivity</title>
      <p>
        The process of aging increases the chances of health complications,
such as morbidity. Morbidity has shown to be closely associated
with functional decline, which consequently can increase
progression towards developing greater impairment [
        <xref ref-type="bibr" rid="ref30">30</xref>
        ]. PA has shown
that it can play an important role in healthy aging [
        <xref ref-type="bibr" rid="ref43">43</xref>
        ] as well
as improving the quality of life of those facing impairments [
        <xref ref-type="bibr" rid="ref21">21</xref>
        ]
through improved functioning. Although physical inactivity has
more direct consequences for older adults due to the combination
of natural physical and mental decline over time, it is important to
adhere to enough PA throughout a lifespan to mitigate the chances
on complications later on in life.
      </p>
      <p>
        There are many underlying factors of physical inactivity, such as
environmental, demographic, psychological, and cognitive factors
(see for an overview [
        <xref ref-type="bibr" rid="ref46">46</xref>
        ]). Aside from the environmental factors,
these PA barriers are often grounded in misconceptions and beliefs
of people’s own functioning in relation to PA. There are several
opportunities to support the determinants of PA, such as through
the (combined) use of persuasive technologies, serious games,
personalization, and adaptation.
2.2
      </p>
    </sec>
    <sec id="sec-5">
      <title>Persuasive Technologies</title>
      <p>
        An abundance of applications have been developed to promote PA
(see for an overview [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]). Although numerous applications exist,
they in general lack persuasive strategies to keep users engaged
and motivated in their behavioral change. To increase the
efectiveness of applications, knowledge can be drawn from behavioral
theories (see for an overview of the behavioral theories that have
been used [
        <xref ref-type="bibr" rid="ref34">34</xref>
        ]) to develop persuasive solutions. Lin et al. [
        <xref ref-type="bibr" rid="ref29">29</xref>
        ] used
positive and negative reinforcement to facilitate motivation and
eficacy. They showed that anticipated negative reinforcement can
have negative efects on motivation to engage in an activity.
However, Midden and Ham [
        <xref ref-type="bibr" rid="ref33">33</xref>
        ] showed that it is especially the negative
social feedback that contributes to the encouragement of an activity.
Hence, negative social feedback seems to be especially useful to
encourage people to go the extra mile but loses its value when used
to motivate people to engage in an activity.
      </p>
      <p>
        Others have used social influencing mechanisms (e.g., social
sharing, support, and comparison) to motivate users in a behavioral
change (e.g., [
        <xref ref-type="bibr" rid="ref28 ref50">28, 50</xref>
        ]). Young [
        <xref ref-type="bibr" rid="ref50">50</xref>
        ] used Twitter to facilitate
realtime information sharing in order to modify behaviors. Lim et
al. [
        <xref ref-type="bibr" rid="ref28">28</xref>
        ] developed a shoe accessory that glows brighter as the wearer
increases their physical activity.
      </p>
      <p>
        Another strategy that has been frequently adhered to is the use
of persuasive messages, such as in reminders (e.g., [
        <xref ref-type="bibr" rid="ref47">47</xref>
        ]) and alerts
(e.g., [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]). Tsai et al. [
        <xref ref-type="bibr" rid="ref47">47</xref>
        ] developed a mobile application geared
towards diabetic patients for self-monitoring their daily caloric
balance (i.e., consumption and energy expenditure) by providing
reminder prompts on their current status. Chatterjee et al. [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] used
sensor data to provide alerts to diabetic patients on their activity
and physiological parameters to promote behavioral change.
2.3
      </p>
    </sec>
    <sec id="sec-6">
      <title>Serious Games</title>
      <p>
        Persuasive technologies on its own follows the assumption that
behavioral change is mainly achieved through raising awareness
and changing attitudes. However, prior studies have shown that a
raised awareness [
        <xref ref-type="bibr" rid="ref51">51</xref>
        ] or a change of attitude [
        <xref ref-type="bibr" rid="ref52">52</xref>
        ] do not necessarily
precede a behavioral change, but may have been influenced by other
factors. Learning on the other hand have been identified as a key
component for behavioral change [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>
        One way to efectively educate is with the use of serious games
through engagement. Serious games are games that are used for
the purpose other than just entertainment. These kind of games use
game elements of entertainment to train and/or educate its users.
Serious games have been used to teach science and technology, for
example in learning about biology through protein folding [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] and
learning coding through solving puzzles [
        <xref ref-type="bibr" rid="ref24 ref26">24, 26</xref>
        ]. The use of serious
games within the health domain mainly focuses on either training
or educational aspects (see for an overview [
        <xref ref-type="bibr" rid="ref48">48</xref>
        ]). For example,
research focusing on older adults have mainly used serious games
to train them with a certain skill [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. One of the determinants of
PA that has received considerable attention among older adults
is the fear of falling. Levy et al. [
        <xref ref-type="bibr" rid="ref27">27</xref>
        ] mitigated the fear of falling
by combining virtual reality therapy with serious games. Silva et
al. [
        <xref ref-type="bibr" rid="ref41">41</xref>
        ] created a multiplayer game for senior care centers to train
older adults in balancing and muscle strength to prevent falling
with including social aspects at the same time.
      </p>
      <p>
        Serious games depicting educational aspects mainly focus on
lifestyle and dietary purposes. Peng [
        <xref ref-type="bibr" rid="ref36">36</xref>
        ] used a serious game design
to educate players about how their food choices influences physical
attributes (e.g., weight and their current goal). Amaro et al. [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]
created a game named "Kalèdo" for middle school children (age
1114) that provided nutritional information about food to influence
their dietary behaviors.
2.4
      </p>
    </sec>
    <sec id="sec-7">
      <title>Personalization &amp; Adaptation</title>
      <p>
        Personalization and adaption is a common practice in fields as
recommender systems (e.g., [
        <xref ref-type="bibr" rid="ref11 ref13 ref25">11, 13, 25</xref>
        ]). Especially, theory-based
personalization strategies are receiving increased interest next to more
data-driven approaches. These strategies are often based on higher
level characteristics, such as cultural values (e.g., [
        <xref ref-type="bibr" rid="ref12 ref17 ref39 ref40 ref42">12, 17, 39, 40, 42</xref>
        ])
or lower level characteristics, such as personality traits (e.g., [
        <xref ref-type="bibr" rid="ref10 ref14 ref15 ref16 ref18 ref45">10, 14–
16, 18, 45</xref>
        ]). However, prior studies within health using serious
games or persuasive technologies usually adhere to a
one-sizeifts-all approach (e.g., assigning a fixed goal to all participants).
Especially within the health domain, this one-size-fits-all approach
is not suitable for everybody and can even result in harmful
behaviors. Hence, tailoring solutions to users’ behaviors, preferences, and
needs through personalization and adaptation is necessary. The
works that adhered to some kind of personalization or adaptation
have shown positive results in increasing the efectiveness of the
intended purpose of the serious game and/or intervention. For
example, Adams et al. [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] showed to be efective in promoting PA
by using the 60th percentile as a future goal setting based on the
performance of the last week. Gerber et al. [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ] used personalized
text messages that included tips on healthy eating and physical
activity, as well as reminders and expressions of encouragement.
      </p>
      <p>
        With the abundance of sensors available through the
pervasiveness of smart devices, smart interventions can be created to further
support the PA determinants. For example, connected to a mobile
application, Hurling et al. [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ] used an accelerometer to
automatically capture exercise data, whereas Fukuoka et al. [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ] used digital
pedometers to collect step data to track activity and create
interventions. Although these solutions are focused on automatic capturing
of activities, sensors can also be used to map the surroundings
of people to suggest more suitable PA alternatives. For example,
sensors can be used to detect local weather or GPS can be used to
track useful facilities in the proximity of people.
3
      </p>
    </sec>
    <sec id="sec-8">
      <title>PROPOSAL</title>
      <p>
        We propose a game that adopts many of the gameplay elements
of a popular standalone device from the past called Tamagotchi.
A Tamagotchi is an egg-shaped handheld digital pet, created in
Japan in 1996 (see Figure 1), which sparked a craze of popularity
upon its release. The goal of the Tamagotchi game is for the user to
take care of an amorphous blob to have it grow and mature. Caring
for the Tamagotchi involves monitoring its happiness. The
happiness of the Tamagotchi is influenced by the amount of attention
given to it by its user. For example, feeding and playing with the
Tamagotichi has a positive influence on its happiness. However,
overfeeding can cause sickness and will require medicine.
Ignoring your Tamagotchi for extended amounts of time, not feeding
it enough, or not providing medicine when it becomes sick may
cause it to die. Therefore, caring for a Tamagotchi stimulates the
creation of an emotional attachment and awareness of how to take
proper care of a pet. The game taps into our basic psychological
need of relatedness [
        <xref ref-type="bibr" rid="ref38">38</xref>
        ], which includes taking on responsibility
through nurturing, caring, and enjoyment of interacting with a
pet [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ]. In this position paper we propose a personalized serious
game to promote PA that is inspired by the Tamagotchi concept. By
additionally incorporating both educational and training aspects
on PA we hope to facilitate long term behavioral change.
3.1
      </p>
    </sec>
    <sec id="sec-9">
      <title>Features</title>
      <p>Our game adopts the Tamagotchi concept of caring in the form of
a mobile application. However, instead of caring for a virtual pet,
we propose to personalize the virtual character by letting it be a
reflection of oneself (i.e., the user) by customizing the game
character with a cartoon avatar of the user (see Figure 2). Consequently,
the (in)actions taken by the user will educate them directly on the
anticipated health efects as it will be reflected in the condition
of the character, such as changes in the emotional and physical
state. Furthermore, PA and other recommended behaviors will be
promoted through training (e.g., providing suggestions for certain
activities and how to execute them) as well as through education by
educating users on the health benefits of engagement (which will
then also be visually reflected through the virtual character). For
example, the game would require the character to hydrate
throughout the day, take a minimum number of steps, eat (healthy) food,
and raise the heartbeat to a particular range for a specific amount
of time. Strategies to convey the persuasion to engage in the PA
can be personalized to maximize its efect (e.g., based on cultural
values and/or personality traits).</p>
      <p>Data of activities can unobtrusively be captured through sensors
of smart devices (e.g., smartphones, wearable technologies). For
example, smartphones nowadays have an abundance of sensors
available that can accurately capture the movements of its user.
Also, the increased adoptation of wearable technologies provide
opportunities to gain information about the activities and the
physical condition of the user. For those activities we cannot obtain data
of (e.g., drinking liquids) and for those who opt not to use these
built-in sensors in their devices, we can have an option for user
to input their own data. Although this introduces the ability for
potential cheating, we believe that long-term and serious players
would not exploit this privilege as the gameplay would be similar
to that of the original Tamagotchi in this case. One well-known
aspect of the Tamagotchi is its constant need for attention and
its tendency to notify/signal its owner (and those in the vicinity)
with beeping sounds at inopportune moments (e.g., in a meeting,
during class, while sleeping). The Tamagotchi device itself is quite
simple (with three buttons, a speaker, and a low-resolution LCD
screen) and does not include any sensors. There is an option to
turn of the speakers, but doing so could possibly result in negative
consequences for the Tamagotchi since the owner cannot be
signaled to take care of its needs immediately. We plan to address this
interruption issue by integrating with the users’ data (e.g., a user
should not be interrupted during all or certain types of calendar
event), sensors (e.g., a user should not be interrupted if the device
is face down on a flat surface), and customizable preferences (e.g.,
the user can always be interrupted when connected to a specific
WiFi network, but not when they are within the boundaries of a
GPS geo-fence or connected to their vehicle’s bluetooth speakers).</p>
      <p>Contextual data (e.g., location data, WiFi connectivity, local
weather reports, and calendar events) can also be used to determine
the context of the user so that the game could suggest
locationrelevant and/or location-appropriate activities, and thereby
lowering the threshold of engagement. For example, it could suggest and
give examples of stretching activities to a user in their ofice,
suggest speeding up their pace when they are walking in a large open
space outside to increase their heart rate, recommend a longer
jogging route, or provide alternative activities based on local weather
(e.g., suggest indoor activities when it detects bad weather).</p>
      <p>By aggregating the data mentioned above, we can use machine
learning techniques to recognize behavioral patterns and predict
future whereabouts. These predictions can further support the
adaptation of interventions in users’ everyday life by customizing
the recommended activities. For example, if a user did not follow
the advised activities throughout the day and the prediction models
determine that there is only one activity window left in the user’s
day, the game could recommend a more intense activity program
(within the user’s capabilities and context) to reach or approximate
the initial activity goal.
4</p>
    </sec>
    <sec id="sec-10">
      <title>OPEN RESEARCH QUESTIONS</title>
      <p>The proposed serious game opens up new research opportunities
that can provide new insights on how to efectively promote PA
through diferent kinds of activities and sensors.</p>
      <p>One avenue to explore is how the representation of self may
influence one’s behavior and interaction with the application. For
example, if the game character is an avatar of a user, will the user
be more willing to take care of their own body so that it takes care
of their digital self? What about social connections - will a user feel
more obligated to take care of their body if they know other people
can see their avatar’s fitness status? Will providing explanations and
transparency on why certain activities are recommended increase
the engagement of users?</p>
      <p>There are also open questions about the data sources and sensors
(and diferent combinations of these) informing the game, and how
that might afect gameplay and users’ motivation. This is important
as diferent devices might only have certain sensors or data sources
available. For example, how would users react to a game that only
uses a step tracker, or just a heart rate monitor? Depending on
how many sensors are informing the game may lead to diferent
experiences, expectations, and usage by users.</p>
      <p>We can test these ideas through a controlled experiment,
comparing diferences in usage. For example, for the first three questions
mentioned above, we can run experiments manipulating a
combination of the following: the avatar’s visualization (self or generic
image), connection to social networks (show or do not show character
on social network), and the efect of providing activity interventions
with and without explanations and transparency.</p>
    </sec>
  </body>
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