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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>From Smartphone Zombies to Natural Language Processing - Designing and Evaluating Behavior Change Support Systems</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Pasi Karppinen</string-name>
          <email>pasi.karppinen@oulu.fi</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sriram Iyengar</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Lisette van Gemert-Pijnen</string-name>
          <email>j.vangemert-pijnen@utwente.n</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Harri Oinas-Kukkonen</string-name>
          <email>harri.oinas-kukkonen@oulu.fi</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>COM Phx Internal Medicine, BIO5 Institute, University of Arizona</institution>
          ,
          <country country="US">USA</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Oulu Advanced Research on Service and Information Systems Group, Faculty of Information Technology and Electrical Engineering, University of Oulu</institution>
          ,
          <addr-line>Oulu</addr-line>
          ,
          <country country="FI">Finland</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Psychology, Health &amp; Technology, Faculty of Behavioural, Management and Social Sciences, University of Twente</institution>
          ,
          <addr-line>Enschede</addr-line>
          ,
          <country country="NL">The Netherlands</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>The Eighth International Workshop on Behavior Change Support Systems was held as a virtual event due to the CoVid19 crisis. Despite of the challenging situation, researchers from around the globe joined together to discuss recent advances in Behavior Change Support Systems research. A wide variety of topics was presented from multiple perspectives. The selected papers can be separated to three themes: design and development; user and stakeholder involvement; and evaluation of Behavior Change Support Systems.</p>
      </abstract>
      <kwd-group>
        <kwd>behavior change support systems</kwd>
        <kwd>BCSS</kwd>
        <kwd>persuasive design</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>Behavior Change Support Systems (BCSS) workshop builds around the concept of
systems that are specifically designed to support and help behavior change in groups or
individuals. The forefront of this workshop from the very beginning has been the highly
multi-disciplinary nature of designing and implementing behavior change strategies
and systems. It is a forum for experts from multiple disciplines, where they can present
their work and discuss the faced challenges in the realm of behavior change. The
workshop provides a platform for researchers, students and practitioners to share experiences
and latest knowledge of BCSSs using behavior change models. This volume comprises
the workshop proceedings of the 8th International Workshop on Behavior Change
Support Systems (BCSS 2020) that took place on April 21st, 2020 in conjunction with the
15th International Conference on Persuasive Technology 2020 hosted by Aalborg
University in Denmark. The proceedings of BCSS 2020 include five research papers,
two work-in-progress papers and a position paper.</p>
      <p>
        Information and communication technology (ICT) has found its way into nearly all
aspects of life. Homes and workplaces are filled with technology and it is increasingly
ubiquitous and embedded in everyday life objects. Increasing amount of people are
carrying technology on themselves wherever they go: fitness trackers, wearable
sensors, and smart watches are becoming more and more common. Smart phones have
become essential part of everyday life, and mobile services are basically everywhere
and to be consumed instantly, contributing towards humanizing ICT [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ].
      </p>
      <p>
        With the continuous presence of technology, there is also continuous presence of
persuasion. Persuasion as such is not new, we have been persuaded to behave certain
ways throughout our lives from schools to buying groceries. Also, technology has never
been neutral either, it always influences to our lives whether we want it or not [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
However, technology of today is becoming increasingly aware of the context of its use,
and it can identify opportune situations to help people to change or maintain desired
behaviors. Latest technological developments offer overwhelming possibilities to
deliberately influence the behavior of individuals, and it is highly important for designers
select the right strategies and to be thoughtful of the possible outcomes of the ICT. The
Persuasive Systems Design Model (PSD) [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] has received significant appreciation over
the years when evaluating, designing and developing systems with persuasive intent.
The PSD model provides a framework to systematically examine persuasive design
elements and its categories of BCSS interventions. Naturally as the scientific field
evolves further, there is a need to acquire deeper understanding of different PSD/BCSS
constructs and evaluation methodologies to measure and predict effectiveness of ICT.
We also need to understand the risks and benefits of new technologies that allow us to
gather enormous amounts of data from multiple sources to customize and personalize
persuasive activities [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. Even though technological development offers new business
and research possibilities, our BCSS community should not lose sight from serious
concerns and possible ethical risks either [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ].
      </p>
      <p>
        The nature of behavior change merits further studies as well. Research in cognitive
psychology suggests that largely autonomous processes can play a significant role in
many behaviors: perception and even choice can have non-conscious roots [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. In other
words, changing intentions, beliefs and attitudes sometimes might not be enough for
controlling behaviors. In addition, persuading an individual to behave certain way can
be a onetime trigger, but often permanent behavior change requires continuous support
for a longer period [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. Especially many health challenges like obesity or depression
requires long-term commitment from individuals. As important it is to study and the
immediate effects of BCSSs, it is equally vital to have the broader time span view on
the use and effects of these systems. In practice the formation of healthy habits can be
a combination of various different behavior support strategies [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. As a BCSS’s aim is
to impact people’s lives, more studies on the use of ICT in their actual contexts are
necessary to study how different strategies can help people to achieve better lifestyles
in practice. These issues pose real challenges for practitioners and researchers in the
field of Behavior Change Support Systems (BCSSs). A BCSS can be defined as “a
socio-technical information system with psychological and behavioral outcomes
designed to form, alter or reinforce attitudes, behaviors or an act of complying without
using coercion or deception” [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>Behavior support strategies embedded in ICT products can have enormous impact
on personal health, societies’ overall well-being, and even the state of global ecology.
These opportunities cannot be faced by practitioners and researchers from one
discipline alone. They require interdisciplinary perspective and collaboration between
business, public sector, and academia. BCSS workshop is one of the prominent venues to
establish fruitful networks now and in the future.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Presented Work</title>
      <p>The workshop in 2020 comprised new and interesting work on BCSSs. In this eighth
occurrence of the BCSS workshop, we have eight papers presented by an international
network of researchers. The papers of the BCSS 2020 workshop address three timeless
themes in BCSS: design and development of effective behavior change support
systems, involving end users and other stakeholders, and evaluation of Behavior Change
Support Systems. We will next highlight, in brief, the key ideas behind the papers
included to the proceedings of the workshop.
2.1</p>
      <p>
        Design and Development of Effective Behavior Change Support Systems
Preliminary study on the smartphone zombie phenomenon by utilising a monitoring
application by Kashimoto, Hyry, Karppinen, Oinas-Kukkonen, Taya, and Ono [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]
study how to persuade people not to use a smartphone while walking. This type of
behavior is also known as “smartphone zombie” activity, and it can lead to very
dangerous accidents in the urban environment. Kashimoto and colleagues investigates
smartphone zombie behavior by designing a monitoring app that was correlated to
personality data using the Trans-theoretical model and the pathway model for problematic
phone use.
      </p>
      <p>
        Multi-perspective persuasion by a council of virtual coaches by Huizing, Klaassen,
and Heylen [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] experiment perceptions of three virtual agents providing tips on weight
loss. They compare two conditions, in one condition the coaches merely gave tips, and
in the other they had brief discussions in between the tips. They found that the
intercoach discussion during a coaching session did have an effect e.g. in users’ perceptions
and commitment.
      </p>
      <p>
        Embedding Additional Behaviors Into Users’ Daily Routines for Improving Users’
Awareness of Self-Health Condition by Zhang, Matsuda, Fujimoto, Arakawa, and
Yasumoto [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] presents very interesting design, where office workers who weight
themselves can use a microwave in a break room. This new design aims to promote
behavior changes by embedding additional behaviors into users' daily routines, trying
to improve users' awareness of their health condition.
2.2
      </p>
      <sec id="sec-2-1">
        <title>Involving End Users and Other Stakeholders</title>
        <p>
          A Multi-stakeholder Process of Designing a City Platform for Sustainable Behavior:
Lessons Learned by Paraschivoiu, Layer-Wagner, Meschtscherjakov, Möstegl,
Stabauer [
          <xref ref-type="bibr" rid="ref11">11</xref>
          ] applied a user-centered approach to engage multiple stakeholders in the
design of a web and mobile sustainability platform. They structured a process engaging
local administration, service providers and citizens. Changing behaviors with respect
to climate change is a complex problem that involves not only end users, but other
stakeholders as well. Paraschivoiu and colleagues argue that stakeholder engagement
is a continuous process and designers need to ensure agency of all those involved.
        </p>
        <p>
          Living Lab for Designing Behavior A-Change by Yasuoka [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ] proposes to apply
Living Lab as an approach to design attitude change. Living Lab supports in-depth
understanding of the target user and their motivations, needs and their transition over
longterm period. Study is based on two research cases that introduce the potential of
designing Behavior Change Support System by means of Living Lab principles.
        </p>
        <p>
          Combining personalization, tailoring, persuasive design and gamification – Where
Do We Stand? by Enwald [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ] reminds that the idea of taking personal characteristics
into account in attempts to change behavior is not new. The aspects of tailoring or
personalizing have been emphasized in persuasive system design, gamification research,
and health communication. Enwald argues that lot could be learned from what is
already known and done in other research fields. Multidisciplinary or even
interdisciplinary research approaches could be useful for seeing the bigger picture in the future.
2.3
        </p>
      </sec>
      <sec id="sec-2-2">
        <title>Evaluation of Behavior Change Support Systems</title>
        <p>
          Increasing amount of mobile health apps aims to relief stress, which impacts physical,
mental and emotional health. A Systematic Review of Persuasive Strategies in Stress
Management Apps by Alhasani, Mulchandani, Oyebode, and Orji [
          <xref ref-type="bibr" rid="ref14">14</xref>
          ] use the primary
task support strategies of the Persuasive Systems Design (PSD) framework to evaluate
the persuasiveness of 60 stress management apps. The results reveal that
personalization is the most commonly employed strategy overall, followed by self-monitoring,
simulation, and tailoring.
        </p>
        <p>Within the mental health problem domain Deconstructing Persuasive Strategies in
Mental Health Apps Based on User Reviews using Natural Language Processing by
Oyebode and Orji introduce the use of Text Mining method to extract knowledge from
unstructured text data. In their text mining approach Oyebode and colleagues used
natural language processing (NLP) techniques, especially topic modelling. They used as a
sample 100 user reviews of mental health apps and studied their persuasive strategies.
3</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Discussion</title>
      <p>Need for interdisciplinary approaches and the benefits of viewing BCSSs from different
perspectives was shown at the workshop once again. The papers provided valuable
input for the online workshop and an occasion for researchers and practitioners to discuss
the key issues for developing and evaluating BCSSs.</p>
      <p>There is a demand for academic knowledge of how to apply latest technologies for
behavior change from personal health to battling global climate change. In the
upcoming years BCSS workshop will act as a multidisciplinary venue where experts from
various backgrounds and domains, such as psychology, human-computer interaction,
information sciences and medicine can present their studies and discuss new
possibilities in the field of Behavior Change Support Systems.
4</p>
    </sec>
    <sec id="sec-4">
      <title>Acknowledgements</title>
      <p>This year’s implementation of the workshop was organized by Programme chairs prof.
Sriram Iyengar (University of Arizona, USA) and Dr Pasi Karppinen (University of
Oulu, Finland). The founders and general co-chairs of the workshop series are Harri
Oinas-Kukkonen (University of Oulu, Finand) and Lisette van Gemert-Pijnen
(University of Twente, The Netherlands). The workshop was held in conjunction with the 15th
International Conference on Persuasive Technology 2020 hosted by Aalborg University
in Denmark. Due to a challenging situation by the CoVid19 pandemic, workshop was
held as a video conference. We want to express our highest gratitude for participants’
active attendance and their patience and understanding of the demanding
circumstances.</p>
      <p>Finally, we thank Liisa Kuonanoja (University of Oulu, Finland) for her administrative
work in compiling the proceedings.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          1.
          <string-name>
            <surname>Oinas-Kukkonen</surname>
            <given-names>Harri</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Oinas-Kukkonen Henry</surname>
          </string-name>
          (
          <year>2013</year>
          ).
          <article-title>Humanizing the Web: Change and Social Innovation</article-title>
          . Palgrave Macmillan, Basingstoke, UK.
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          2.
          <string-name>
            <surname>Oinas-Kukkonen</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Harjumaa</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          (
          <year>2009</year>
          ).
          <article-title>Persuasive systems design: Key issues, process model, and system features</article-title>
          .
          <source>Communications of the Association for Information Systems</source>
          ,
          <volume>24</volume>
          (
          <issue>1</issue>
          ),
          <fpage>28</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          3.
          <string-name>
            <surname>Mayer-Schonberger</surname>
            <given-names>V</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Cukier</surname>
            <given-names>K.</given-names>
          </string-name>
          (
          <year>2013</year>
          ).
          <article-title>Big Data: A revolution that will transform how we live, work and think</article-title>
          .
          <source>Houghton Mifflin Harcourt</source>
          , New York.
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          4.
          <string-name>
            <surname>Karppinen</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Oinas-Kukkonen</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          (
          <year>2013</year>
          , April).
          <article-title>Three approaches to ethical considerations in the design of behavior change support systems</article-title>
          .
          <source>In International Conference on Persuasive Technology</source>
          (pp.
          <fpage>87</fpage>
          -
          <lpage>98</lpage>
          ). Springer, Berlin, Heidelberg.
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          5.
          <string-name>
            <surname>Custers</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Aarts</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          (
          <year>2010</year>
          ).
          <article-title>The unconscious will: How the pursuit of goals operates outside of conscious awareness</article-title>
          ,
          <source>Science</source>
          ,
          <volume>329</volume>
          (
          <issue>47</issue>
          ),
          <fpage>47</fpage>
          -
          <lpage>50</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          6.
          <string-name>
            <surname>Oinas-Kukkonen</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          (
          <year>2013</year>
          ).
          <article-title>A foundation for the study of behavior change support systems</article-title>
          .
          <source>Personal and ubiquitous computing</source>
          ,
          <volume>17</volume>
          (
          <issue>6</issue>
          ),
          <fpage>1223</fpage>
          -
          <lpage>1235</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          7.
          <string-name>
            <surname>Karppinen</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Oinas-Kukkonen</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Alahäivälä</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Jokelainen</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Teeriniemi</surname>
            ,
            <given-names>A. M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Salonurmi</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Savolainen</surname>
            ,
            <given-names>M. J.</given-names>
          </string-name>
          (
          <year>2018</year>
          ).
          <article-title>Opportunities and challenges of behavior change support systems for enhancing habit formation: a qualitative study</article-title>
          .
          <source>Journal of Biomedical Informatics</source>
          ,
          <volume>84</volume>
          ,
          <fpage>82</fpage>
          -
          <lpage>92</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          8.
          <string-name>
            <surname>Kashimoto</surname>
            ,
            <given-names>Y.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Hyry</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Karppinen</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Oinas-Kukkonen</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Taya</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>O.</surname>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>Preliminary study on the smartphone zombie phenomenon by utilising a monitoring application</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS</source>
          <year>2020</year>
          ), Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          9.
          <string-name>
            <surname>Huizing</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Klaassen</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Heylen</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>Multi-perspective persuasion by a council of virtual coaches</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS</source>
          <year>2020</year>
          ), Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          10.
          <string-name>
            <surname>Zhang</surname>
            ,
            <given-names>Z.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Matsuda</surname>
            ,
            <given-names>Y.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Fujimoto</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Arakawa</surname>
            ,
            <given-names>Y.</given-names>
          </string-name>
          &amp;
          <string-name>
            <surname>Yasumoto</surname>
            <given-names>K.</given-names>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>Embedding Additional Behaviors Into Users' Daily Routines for Improving Users' Awareness of SelfHealth Condition</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS</source>
          <year>2020</year>
          ), Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          11.
          <string-name>
            <surname>Paraschivoiu</surname>
            ,
            <given-names>I.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Layer-Wagner</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Meschtscherjakov</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Möstegl</surname>
            ,
            <given-names>N.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Stabauer</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>A Multi-stakeholder Process of Designing a City Platform for Sustainable Behavior: Lessons Learned</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS</source>
          <year>2020</year>
          ), Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          12.
          <string-name>
            <surname>Yasuoka</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>Living Lab for Designing Behavior A-Change</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS</source>
          <year>2020</year>
          ), Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          13.
          <string-name>
            <surname>Enwald</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>Combining personalization, tailoring, persuasive design and gamification</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS</source>
          <year>2020</year>
          ), Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          14.
          <string-name>
            <surname>Alhasani</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Mulchandani</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Oyebode</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Orji</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>A Systematic Review of Persuasive Strategies in Stress Management Apps</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS2020)</source>
          , Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          15.
          <string-name>
            <surname>Oyebode</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          , &amp;
          <string-name>
            <surname>Orji</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          (
          <year>2020</year>
          ).
          <article-title>Deconstructing Persuasive Strategies in Mental Health Apps Based on User Reviews using Natural Language Processing</article-title>
          .
          <source>Proceedings of the Eight International Workshop on Behavior Change Support Systems (BCSS</source>
          <year>2020</year>
          ), Aalborg, Denmark, April
          <volume>21</volume>
          .
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>