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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>An Avatar Creator as a Tool for Constructing a Personalized Persuasive Profile</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Marta Kaczmarczyk</string-name>
          <email>m.e.kaczmarczyk@tue.nl</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Panos Markopoulos</string-name>
          <email>p.markopoulos@tue.nl</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Eindhoven University of Technology</institution>
        </aff>
      </contrib-group>
      <abstract>
        <p>Several scholars have argued that it can be more effective to tailor the persuasive approach to different individuals, by personalizing the way by which a system attempts to influence user's behavior. Here we discuss how gamification can be used to construct a user profile that predicts the susceptibility of the user to different social influence approaches. We describe the design concept and the experimental evaluation of an avatar creator application which collects data on susceptibility of users to Cialdini's principles of influence to enable personalization of persuasion.</p>
      </abstract>
      <kwd-group>
        <kwd>Social influence</kwd>
        <kwd>Gamification</kwd>
        <kwd>Persuasion profiling</kwd>
        <kwd>Tailored persuasion</kwd>
        <kwd>Individual differences</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>
        The effectiveness of self-monitoring and quantified-self applications designed to
support healthy living and health interventions depend upon sustained engagement with
the application (e.g. [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]). Ensuring engagement is thus a key challenge for designers of
such systems and arguably one of the grand challenges for research in the field of
persuasive technology. To achieve this aim researchers turn to theories such as social
cognitive theory [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], behavioral change theory [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ] or decision making theory [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] to draw
users into regular and long-term use. This approach has produced some encouraging
results, like in case of use of well-timed or pleasantly worded reminders [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] or
employment of goal setting [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. Theories and models of behavior change and persuasive
communication are known to be effective overall, meaning that in a given population they
produce a positive effect on average. However, it has been noted how for a particular
individual any one of these approaches may not work or may even produce the opposite
effect to what was intended by the designer [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. Personalization and tailoring the
motivational approach to each individual user could be the way to address these individual
differences.
      </p>
      <p>
        There are many frameworks on which a personality profiling can be based.
Following the work of Kaptein et al., [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] we exploit the framework proposed by Robert
Cialdini [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] which identifies six influence strategies, a much shorter list than the
frameworks provided by Fogg [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ], Kellermann and Cole [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ], or Rhoads [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. Cialdini’s six
principles of influence, which are very popular, specifically in the domain of electronic
retail, can be summarized as follows:
 Authority - having more trust in things that are recommended by an expert or other
authority
 Consensus - having more trust in things that are popular or endorsed by people that
we like
 Consistency and commitment - tendency to stick with something which we already
have chosen or committed to do
 Scarcity - being drawn by things that are hard to get or are hard to come by
 Liking - tendency to comply with requests made by people we like
 Reciprocity - the need to pay back what we received from others
      </p>
      <p>
        Following the approach by Kaptein et al. [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ] a persuasion profile models how likely
a user is to be persuaded by each of the six strategies above. A system aiming to support
behavior change can personalize its persuasive approach by tailoring persuasive
messages to fit this profile. For example, if a user is more susceptible to persuasive attempts
using the consensus principle then the system might attempt to persuade this user by
mentioning that other users are also engaged in the desired behavior.
      </p>
      <p>
        The simplest way to measure users’ susceptibility to influence principles is with the
use of a classic psychometric survey. Kaptein [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] developed the Susceptibility to
Persuasive Strategies questionnaire (from now on STPS) that measures susceptibility to
each of Cialdini’s principles. The problem of this approach, which is inherent to
questionnaire instruments, is the respondents’ lack of engagement with questions – surveys
can be perceived as boring and various phenomena such as satisficing or social
desirability bias may lead to erroneous responses.
      </p>
      <p>
        In order to make explicit profiling more pleasant and thus avoid these phenomena
we examine how to make explicit user profiling a more engaging and playful
experience. Specifically we examine whether the profiling can be presented to users in the
playful form of an avatar creation tool. By configuring an avatar of a coach/guide that
will be featured in the coaching application and an avatar of himself/herself, indirectly
provides self-report data on his/her susceptibility to Cialdini’s principles. We report
how the transformation from the STPS into an avatar creation tool was conducted
through a user-centered design process that seeks to enhance the engagement with a
coaching application addressing mild-cognitive impairment in the elderly. The
rationale behind the avatar creation tool is twofold: a) increasing engagement with the
STPS questionnaire through gamification, b) increasing engagement with the coaching
application by introducing avatars. Research indicates that for certain groups of users,
particularly the elderly, the avatars of a coach and of the user promote regular use
through increased engagement with the application and by creating a bond with the
avatar characters [
        <xref ref-type="bibr" rid="ref13 ref14 ref15 ref16">13–16</xref>
        ].
      </p>
    </sec>
    <sec id="sec-2">
      <title>Design of a persuasion profiling avatar builder</title>
      <p>The concept of an avatar-building tool, as a way of constructing persuasion profiles,
has been conceived as part of a larger project aiming to create a coaching application
for elderly users with mild cognitive impairment. The aim of this application is to
provide alternative strategies to memorize information. While the persuasion profile is
intended for the specific coaching application, it can be applied in different contexts
where persuasion profiling in terms of the susceptibility to Cialdini’s six influence
strategies can be useful.</p>
      <p>The core idea behind the tool is that the user by making choices pertaining to the
avatar of a coach or of an avatar of himself/herself, or by answering related questions,
will provide data on his/her susceptibility to persuasion. The core concept of the avatar
of a coach is covered by a screen in which the user is asked to choose an avatar of the
guide that will appear in the remaining parts of the application. Choices of the avatars
reflect Cialdini’s authority principle (Fig.1 Screen 1). Then the user chooses the avatar
of herself/himself - choices for the avatar’s clothes correspond to the principles of
susceptibility and scarcity principle (Fig. 1 Screen 2.). Reciprocity, consensus and
commitment (here represented by Fig.1 Screen 3 and 4) are represented by ancillary
questions that follow the choice of avatars.</p>
      <p>Screen 1. Authority principle</p>
      <p>Screen 2. Scarcity principle
Screen 3. Reciprocity principle</p>
      <p>Screen 4. Commitment principle</p>
    </sec>
    <sec id="sec-3">
      <title>Methods</title>
      <p>In order to validate the avatar as a persuasion-profiling tool, we conducted a survey
using crowdsourcing that aimed to establish how choices made during the construction
of the avatar correlate with corresponding responses to the STPS inventory. 150
participants were recruited through Microworkers crowdsourcing platform. Crowdsourcing
was selected as a recruitment strategy due to the fact that correlation analysis requires
a high number of participants and crowdsourcing offers possibility of recruiting large
sample in a very short time frame. The participants were paid $0.55 for completing the
task, which took approximately 10 minutes.</p>
      <p>A prototype avatar creator application was created using Axure. The prototype was
then uploaded onto a crowdsourcing platform called Microworkers to test whether
responses obtained with the avatar creator correlate with the survey responses from the
classic STPS questionnaire. In the prototype only five of Cialdini’s principles were
gamified as the principle of liking proved to be too difficult to transpose effectively in
the avatar creator context.</p>
      <p>The crowd workers participating in the study were first asked to complete the avatar
creator and then to fill in the STPS questionnaire. The data collected was used for
correlation analysis between the replies from the avatar creator questions for each principle
and average score calculated from the group of questions covering each principle in the
STPS questionnaire.</p>
      <p>Inside the avatar creator tested subjects were asked to either complete choice tasks
or answer questions. Examples of the choice tasks and questions are shown in Fig. 1.
4</p>
    </sec>
    <sec id="sec-4">
      <title>Results</title>
      <p>For the whole dataset Cronbach’s α = 0.859 (coefficient omega = .852, 95% CI [.80,
.89]), which indicates high reliability of data. When analyzed per persuasive principle,
most had Cronbach’s α &gt;0.7 (coefficient omega &gt; 0.7). Only the principle of scarcity
was below this level with Cronbach’s α = 0.579 (coefficient omega = .596, 95% CI
[.47, .69]).</p>
      <p>The scarcity principle also proved to be problematic when analyzed through
exploratory factor analysis: When all principles were included, the factors were far from the
grouping of principles. When the scarcity principle was removed the grouping matched
closer to the grouping by principles. We tested data for correlations between choices
made with the avatar creator and the corresponding subscale scores obtained through
the STPS. Prior to the analysis data from the STPS questionnaire was tested for
normality. Only scarcity was normally distributed, all the other principles significantly
deviated from normality. Therefore, the Spearman correlation test was performed on the
authority, reciprocity, commitment and consensus principles and Pearson correlation
test on the scarcity principle.
The results of this experiment confirmed only partly the design rationale of the avatar
creator. The core concept behind the avatar creator tool was that the user will chose the
avatar of a coach that will guide the user in the further parts of the application. The
choice task (Authority1) and the question covering this core concept (Authority2)
correlate with the STPS scores.</p>
      <p>
        Choices regarding the avatar of the user (attempting to cover scarcity principle) did
not correlate with the STPS data for the scarcity principle as had been expected by the
designers. There are two possible reasons for this. Scarcity data from the STPS
questionnaire is not reliable as shown by low Cronbach’s α and results of exploratory factor
analysis, and also noted in the original study by Kaptein [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. Another explanation for
the lack of correlation for the scarcity principle is that the gamified questions do not
pertain to the same construct of scarcity as in the questions of the STPS survey. In the
current design users choose clothes/accessories for their avatar and scarcity hints are
related to some items; however there is a possibility that choices are made on the
appearance or other reason and not because of the scarcity hint given. Ongoing iterative
design of the avatar builder is aimed at removing this possibility.
      </p>
      <p>As for the other principles, reciprocity also cannot be measured by the current
version of the tasks in the avatar creator. The reason why reciprocity did not correlate could
be due to the nature of the questions. The questions were based on the praise/gift idea
followed by a request for a favor. There are many possible explanations for why
participants did not perceive it as similar to the questions in the STPS questionnaire. The
major explanation is that the value of favor was higher than the value of praise/gift to
the participant. New ideas covering this principle should be tested in the next iteration.
The commitment and consensus had one uncorrelated question each. However, the
questions that correlate are sufficient to be used for the purpose of creating a profile of
susceptibility to influence principles.
6</p>
    </sec>
    <sec id="sec-5">
      <title>Conclusions</title>
      <p>Despite the fact that some of the questions in the avatar creator do not correlate with
the average score for each subscale of the STPS questionnaire, there is encouraging
evidence regarding the concept of using an avatar creator tool as a gamified substitute
of this questionnaire. The majority of the gamified principles (authority, commitment
and consensus) significantly correlate with the STPS questionnaire. For the
commitment and consensus variable, one question did not correlate with the average score from
the STPS questionnaire but it is still possible to conclude whether the user is susceptible
to these principles or not. Additionally the key questions covering the core concept of
choosing an avatar of a coach in the applications is also correlated. To improve the
general concept, another iteration of the design shall test new avatar elements for
gauging susceptibility to different influence strategies. Further we are aiming to improve the
scarcity subscale of the STPS so that the questionnaire also can provide data with higher
reliability.</p>
      <p>The avatar creator solution is in line with current trends of concealing classic
questionnaires and alternatively presenting them in a more visually engaging form. The
problem with standard surveys is a high likelihood of the respondents’ lack of
engagement with questions, a phenomena that may lead to erroneous responses. Gamification,
can be a plausible solution to this problem. With our concept, an attempt to make the
classic survey more appealing was pushed even further, aiming to embed self-report in
game mechanics, and more specifically the construction of avatars that will be featured
during game play. This approach seemed particularly appropriate for the context of a
tablet application for coaching elderly with mild cognitive impairment, which is the
design context in which this investigation has taken place. This target group is less
technically savvy and can benefit from the guidance with the use of the application.</p>
      <p>The idea behind the avatar creator is not limited to this project and to the context of
a memory training application or a game. The concept can be easily extended to other
applications or games that require some data collection about the user.</p>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgments</title>
      <p>We thank EIT Health for funding part of this work.</p>
    </sec>
  </body>
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