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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>The Impact of different gamification types in the context of data literacy: An online experiment</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Nikoletta-Zampeta Legaki</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Daniel Fernández Galeote</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Juho Hamari</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Gamification Group, Faculty of Information Technology and Communication Sciences, Tampere University</institution>
          ,
          <country country="FI">Finland</country>
        </aff>
      </contrib-group>
      <fpage>22</fpage>
      <lpage>32</lpage>
      <abstract>
        <p>As the pace at which humans create data increases, a new challenge for individuals and society is to turn a world full of data into a data-driven world. However, data and statistical literacy remain difficult topics to engage with whereas gamification rises as a promising technique to improve motivation. Therefore, we developed a software composed of interactive charts and tools aiming to teach data literacy in four different versions: (i) challenge- (badges), (ii) immersion- (avatars; story), and (iii) social-based (competition) gamification, along with (iv) a control version (no gamification) to compare the effects of different gamification types on learning outcomes. We conducted four-group random assignment pre-, post-test online experiments with students (N=181) from various courses, schools, and educational levels. The primary results of our experiments show a statistically significant improvement in students' performance of almost 44% from using the software. Gamification types did not result in statistically significant differences in students' learning outcomes, suggesting optimism regarding the contribution of interactive data visualization in improving data literacy.</p>
      </abstract>
      <kwd-group>
        <kwd>1 Gamification</kwd>
        <kwd>data literacy</kwd>
        <kwd>statistical literacy</kwd>
        <kwd>education</kwd>
        <kwd>exploratory data analysis</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        We produce and consume data with great ease
and frequency. Even a smartphone can process
and visualize data easier than ever before.
However, this data-explosion is as beneficial as
the insights that we can get from it, and we still
lack a fact-based view of our world [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Data
literacy skills have become so critical that they
have been suggested as a course in secondary
education, highlighting the importance of
“reading and writing with data” [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. These skills
help not only to understand the data around us, but
also support a more rational approach to societal
problems, realizing what is happening by using
data, and eventually dealing rationally with
societal challenges such as climate change or the
COVID-19 pandemic. While we must address
6th International GamiFIN Conference 2022 (GamiFIN 2022),
April 26-29 2022, Finland
EMAIL: zampeta.legaki@tuni.fi (N.-Z..Legaki);
daniel.fernandezgaleote@tuni.fi (D. Fernández.Galeote);
juho.hamari@tuni.fi (J. Hamari)
ORCID: 0000-0002-2707-8364(N.-Z. Legaki);
0000-0002-5197146X (D. Fernández Galeote); 0000-0002-6573-588X (J. Hamari)
️© 2022 Copyright for this paper by its authors. Use permitted under Creative
Commons License Attribution 4.0 International (CC BY 4.0).
      </p>
      <p>
        CEUR Workshop Proceedings (CEUR-WS.org)
these challenges, we still lack motivation to gain
data insights to transform a world full of data into
a data-driven society [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>
        Understanding data might lead to data-driven
and well-informed decision-making at a personal
or societal level [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. Thus, there are online
databases worldwide that provide data sets
regarding a plethora of global topics (e.g.,
economy, the environment, etc.). Despite these
initiatives, people are still discouraged from being
statistically aware of this data, resulting in a
wrong perception of social and economic realities
[
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Even students in statistics courses are
reluctant to partake in them because they consider
them complicated [
        <xref ref-type="bibr" rid="ref5 ref6">5, 6</xref>
        ]. Introductory statistics
courses are an important part of various
disciplines, but neither many teaching approaches
have been noted nor the public understanding of
these topics has been sufficiently advanced,
making research in this direction valuable [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
      </p>
      <p>
        These gaps in pedagogical approaches related
to engagement and motivation have recently
spurred significant interest towards employing
design principles from games as a pedagogical
avenue. Games and gamification have been linked
with intrinsic motivation, so they can be beneficial
in an educational context [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. The online and
virtual educational environments that the
COVID19 pandemic forced to use make the integration of
game-based learning in education even more
appealing. Gamification, or enhancing a product
or service by providing an experience like those
afforded by games, has already been applied in
statistics education with mostly positive results
[
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. Nevertheless, literature reviews on this topic
call for more empirical research and rigorous
comparison among different gamified strategies
to identify methods that effectively attract users’
interest and support education. Empirical research
on the effects of individual or simple motivational
affordances and their comparison regarding
learning outcomes [
        <xref ref-type="bibr" rid="ref10 ref9">9, 10</xref>
        ] is also crucial for
understanding the effects of gamification and its
integration in education.
      </p>
      <p>
        Therefore, in this study, we investigate the
effects of gamification on learning outcomes in
the context of data literacy. We developed a
webbased application that presents statistical concepts
of Exploratory Data Analysis (hereafter EDA)
using a variety of charts and real data. This
application supports three additional versions, one
for each of the following gamification types:
challenge-, immersion-, social-based [
        <xref ref-type="bibr" rid="ref10 ref11">11, 10</xref>
        ]. We
conducted a series of online experiments
supporting random assignment of students
(N=181) to one of the treatments (i.e., control,
challenge-, immersion- and social-based
gamification), using an online pre- and post-test
experimental design. Students come from
different courses, schools, and educational levels.
This study aims to present an interactive
educational application which teaches basic EDA
topics, in a data literacy context, using real data
sets about societal challenges, and to investigate
the impact of different gamification types on
learning outcomes.
      </p>
    </sec>
    <sec id="sec-2">
      <title>2. Background</title>
    </sec>
    <sec id="sec-3">
      <title>2.1. Data Literacy</title>
      <p>
        Our society is becoming more data-rich every
day. The penetration of digital technology in our
daily life has accelerated the digitization and
datafication of our society. These have shed light
on the necessity of critical education about data as
a set of strategies to support individuals in being
aware, and understanding their data [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ], because
data is as useful as the insights, we can get from it
[
        <xref ref-type="bibr" rid="ref13">13</xref>
        ]. Data literacy has been suggested as a
solution leading to a data-driven society [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ].
However, there is not yet a convergence regarding
a definitive set of strategies to achieve data literate
adults. Data literacy is described broadly as “a set
of abilities around the use of data as part of
everyday thinking and reasoning for solving
realworld problems” [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ] or “the ability to understand
and use data effectively (to inform decisions)” [
        <xref ref-type="bibr" rid="ref13 ref16">13,
16</xref>
        ], and it is a crucial life skill nowadays [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ],
from finding employment to supporting
decisionmaking [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. However, data literacy is still in its
infancy. Recent studies argue that it should be
composed of data understanding and data use, but
there is no consensus yet about its components.
Other studies tie data literacy with statistical
literacy [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ] and claim the need for public
understanding of statistics as a rising societal need
to deal with a series of mis-es (e.g.,
misinformation, misunderstandings, etc.) [
        <xref ref-type="bibr" rid="ref18 ref3">3, 18</xref>
        ].
In this regard, statistical literacy, or “the ability to
interpret, critically evaluate, and communicate
about statistical information” [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ], has been
suggested as a desired goal for different
educational levels and professions (e.g.,
researchers, various practitioners) too [
        <xref ref-type="bibr" rid="ref3 ref6">3, 6</xref>
        ].
Acknowledging that there is no universal
definition of data literacy, for the needs of this
study we use the broad definition referred to
above, supported by the concept of statistical
literacy, and see it as an evolving concept that
helps individuals to use data as part of everyday
thinking, get insights from a data-rich society by
using common statistical tools, and supports
solving real-world problems [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ].
      </p>
      <p>
        We are bombarded with statistical news and
data daily, albeit statistics or related fields remain
too complicated and difficult to engage with for
adult learners [
        <xref ref-type="bibr" rid="ref20 ref3 ref5">3, 20, 5</xref>
        ]. Considering the range of
disciplines that provide at least an introduction to
statistics course, the importance of data literacy
skills, and the need for data literate students and
citizens [
        <xref ref-type="bibr" rid="ref21">21</xref>
        ], individuals’ reluctance to engage
with statistics is an urgent problem. In addition,
the content of data or statistical literacy courses
needs to be improved by including real data sets
[
        <xref ref-type="bibr" rid="ref22">22</xref>
        ] and linking statistical concepts with everyday
life topics [
        <xref ref-type="bibr" rid="ref23 ref24">23, 24</xref>
        ]. A few initiatives have been
suggested to promote data or statistical literacy in
lifelong learning with promising results, e.g., the
use of digital technology, workshops with real
problems, and data and game-based/gamified
activities that harness creativity [
        <xref ref-type="bibr" rid="ref15 ref2 ref25 ref26">15, 25, 26, 2</xref>
        ].
However, their limited number, along with a lack
of research on data literacy pedagogy [
        <xref ref-type="bibr" rid="ref12 ref27">12, 27</xref>
        ], set
the basis for exploring gamification’s potential in
this topic.
2.2.
      </p>
    </sec>
    <sec id="sec-4">
      <title>Gamification and data literacy</title>
      <p>
        Hence, this study examines gamification’s
potential given its mainly positive impact in
education. Gamification, defined as an
“intentional process of transforming any activity,
system, service … into one which affords positive
experiences, skills, and practices similar to those
afforded by games” [
        <xref ref-type="bibr" rid="ref28">28</xref>
        ], has been implemented
in a variety of fields, and most empirical studies
focus on education [
        <xref ref-type="bibr" rid="ref10 ref29">10, 29</xref>
        ]. Specifically,
gamification has been mostly employed in
Computer Science, Mathematics and Engineering
[
        <xref ref-type="bibr" rid="ref30 ref31">30, 31</xref>
        ], noting mainly positive results regarding
psychological and behavioral outcomes [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ].
Gamification has gained acceptance in e-learning
educational environments [
        <xref ref-type="bibr" rid="ref32">32</xref>
        ] as well, which
makes it a useful addendum for virtual learning.
      </p>
      <p>
        There are also studies in favor of gamification
in the data and statistics fields, especially in
digital formats [
        <xref ref-type="bibr" rid="ref33 ref8">8, 33</xref>
        ]. Most of these studies focus
on introductory statistics courses, which include
topics related to data and statistical literacy skills
(e.g., basic EDA topics [
        <xref ref-type="bibr" rid="ref40">40</xref>
        ], chart interpretation).
These courses are often taught in various
disciplines. Thus, the need to motivate students
becomes crucial. Other initiatives to increase
student motivation in these fields also use
interactive software or persuasive data
visualization [
        <xref ref-type="bibr" rid="ref35 ref36">35, 36</xref>
        ], with mostly optimistic
results. Despite that most of the studies list the
positive impact of gamification or persuasive data
visualization, their effects seem to vary depending
on the context and the audience [
        <xref ref-type="bibr" rid="ref37">37</xref>
        ].
      </p>
      <p>
        Gamification is sometimes categorized into
three types based on the motivational affordances
used, i.e., challenge/achievement (focusing on the
feeling of competence and using points, badges,
etc.), immersion (putting emphasis on avatars and
narrative), and social (concentrating on
competition and/or collaboration) [
        <xref ref-type="bibr" rid="ref10 ref11 ref38">11, 10, 38</xref>
        ].
[
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] attempted to link these gamification types
with different intrinsic needs satisfaction, i.e.,
autonomy, competence, and relatedness needs,
finding differences among their effects but
concluding to a positive impact of gamification,
overall. Despite the variety of motivational
affordances, still most of the studies focus on the
triad of points-leaderboards-badges [
        <xref ref-type="bibr" rid="ref10 ref29 ref37">10, 29, 37</xref>
        ].
On top of that, negative results in education [
        <xref ref-type="bibr" rid="ref37 ref39">39,
37</xref>
        ] call for more research and cautious design of
gamification in the education process. [
        <xref ref-type="bibr" rid="ref10 ref31 ref9">31, 10, 9</xref>
        ]
also mention the need for more controlled
empirical studies or studies that empirically
compare individual or different types of
motivational affordances and further examine the
conditions in which gamification becomes
effective in different contexts. Combining the
above-mentioned need to evaluate gamification
impacts and the need for increasing and
improving teaching methods regarding data
literacy, within this study we designed and
implemented a system that supports three
gamified versions (i.e., challenge-, immersion-,
social-based gamification), along with a control
version, that aims to teaches data literacy concepts
through interactive charts and real data. Next, we
conducted random assignment experiments using
this system to address the above-mentioned gap.
      </p>
    </sec>
    <sec id="sec-5">
      <title>3. Methods and data</title>
    </sec>
    <sec id="sec-6">
      <title>3.1. Participants</title>
      <p>We conducted online experiments in four
different schools. Schools were recruited based on
the first author’s research network, and teachers’
agreeing upon participant incentives with the first
author. The total sample is composed of N=181
(58.56% male; 40.89% female; 0.05% non-binary
or other) university students. The participants
were students in different courses and schools,
with different educational levels (undergraduate,
postgraduate, and MBA students) as follows:
• 62 students; Forecasting Techniques; School
of Electrical &amp; Computer Engineering,
National Technical University of Athens,
Greece; class 2021; 4th year of undergraduate
studies (FT ECE-NTUA).
• 18 students; Experimental Research Methods;
Business Administration Department,
University of Thessaly, Greece; class 2021;
2nd year of MBA studies (RM MBA-UTH).
• 36 students; Quantitative Methods in
Decision Making, Business Administration
Department, University of Thessaly, Greece;
class 2021; 2nd year of MBA studies (DS
MBA-UTH).
• 22 students; Multimedia and Hyper-media
Theory; University of Pretoria, South Africa,
•
•
class 2021; 2nd year of undergraduate studies
(MHT UPR).
30 students; Forecasting and Data Analytics
via Gamification, Summer School, Tampere
University, Finland; class 2021;
under/postgraduate; (FDAG TAU).
13 students; Special Issues in the Time Project
Management; Business Administration
Department, University of Thessaly, Greece,
class 2021, 4th year of undergraduate studies
(PMUTH).
3.2.</p>
    </sec>
    <sec id="sec-7">
      <title>Materials</title>
      <p>All materials were designed and implemented
to meet the goals of this study, i.e., to effectively
teach basic EDA concepts and compare the effects
of different gamification types on learning
outcomes. The materials of our experiments are
composed of three main parts: a pre-test on-line
questionnaire, a web-based educational
application supporting four different versions (a
control, and three versions of gamified learning),
and a post-test online questionnaire. Every
version of the web-based application matches to
one of the following: control (i.e., no gamification
elements), challenge- (i.e., badges),
immersion(i.e., avatars and a story related to the presented
data), and social-based (i.e., illustrated text about
the participant’s rank among others) gamification.
All the materials are in English. A more detailed
description for each part follows.</p>
    </sec>
    <sec id="sec-8">
      <title>3.2.1. Pre- and post-test</title>
      <p>
        The pre- and post-tests have the same
structure, number of questions, and topics. They
are com-posed of 30 multiple choice questions
related to EDA topics and misconceptions
regarding worldwide data. Even though data
literacy is gaining more importance and there are
some courses available online, our search of
standardized tests about data literary skills did not
conclude to any result. Thus, a 30-question test
was constructed by reviewing related online
courses, data literacy and EDA literature [
        <xref ref-type="bibr" rid="ref34 ref40 ref41">40, 34,
41</xref>
        ], using part of Analytics Vidhya’s test2 (a few
questions from a test about fundamental statistics
skills), including data about the UN 2030
Sustainable Development Goals (hereafter
SDGs)3, and considering our expertise in statistics
and forecasting. We concluded to the following
structure regarding both EDA and data related
topics: central tendency (3 questions), spread (5
questions), growth rate (2 questions), graph
interpretation and data knowledge about SDGs
(14 questions), re-expression of data and
COVID19 pandemic (2 questions), and regression and
correlation (4 questions). Calculating the mean
among some numbers or answering about the
percentage of countries with laws against sexual
harassment at work are some examples. We also
included 2 attention questions. The order of the
questions and answers and the description of some
questions might slightly differ, but the questions
related to the SDGs and the calculations needed to
answer the pre- and post-tests are the same. The
content of the questions is interwoven with the
learning objectives and the content of the
application. The pre- and post-tests are exactly the
same for all the different versions.
      </p>
    </sec>
    <sec id="sec-9">
      <title>3.2.2. Description of the (gamified) educational application</title>
      <p>
        We designed the content and then
implemented a publicly available web-based
application from scratch, which aims to teach
basic EDA [
        <xref ref-type="bibr" rid="ref34 ref40 ref41">40, 34, 41</xref>
        ] and compare different
gamification types (i.e., challenge-, immersion-,
social-based) regarding the learning outcomes. A
brief description of the content and the design of
the application follows:
      </p>
      <p>
        Content design. The main EDA topics were
chosen according to our learning objectives,
wellknown relevant literature [
        <xref ref-type="bibr" rid="ref34 ref41 ref46">46, 34, 41</xref>
        ], our target
audience (i.e., adults), time limitations (a full
round should last for approximately 1 hour), and
the conditions of an online experiment. We opted
for an online system to have students from various
educational background and levels because of the
COVID-19 pandemic restrictions. Our main goal
was to provide data literacy skills to a broad
audience, even to those without a strong statistical
background. We borrowed some of the thematic
axes from online courses, combining them with
relevant literature [
        <xref ref-type="bibr" rid="ref34 ref40 ref41">40, 34, 41</xref>
        ] and our expertise.
The web-based application is divided into 5
discrete pages/levels, and every page is linked
with one topic as follows: page 1: central
tendency; page 2: the spread of data; page 3: chart
interpretation; page 4: re-expression of data; page
5: regression and correlation. The higher the level,
the more complicated the topic is, integrating a
2 https://www.analyticsvidhya.com/
3 https://sdgs.un.org/goals
scaffolding approach [
        <xref ref-type="bibr" rid="ref42">42</xref>
        ]. For each level, an extra
motivational affordance appears (see Figure 1). In
addition, we included small interactive exercises
as practice in four out of the five pages and
colorful buttons at the top of every page that
explained important topics using language as
plain as possible. Figure 1 shows the 3rd page of
the application, the colorful buttons with further
explanation upon clicking on them, and an
interactive chart with an in-application question.
Moreover, we selected data related to the SDGs
and other societal challenges such as the
COVID19 pandemic for the in-application examples and
charts to increase engagement with these issues.
Online open data sources were used, including
Our World in Data, The World bank,
GAPMINDER’s database and report, and others
mentioned in the application.
      </p>
      <p>
        Gamification design. One of the main goals
of this study is to compare the three gamification
types [
        <xref ref-type="bibr" rid="ref10 ref11">10, 11</xref>
        ] in an online application along with
having no gamification, regarding EDA and data
literacy learning outcomes. The distinction
between gamification types is based mainly on
different player motivational directions and the
game elements used, and it has been associated
with slight differences in need satisfaction [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ].
Following the design guidelines by [
        <xref ref-type="bibr" rid="ref43">43</xref>
        ], we
conducted a brainstorming session with six
gamification experts from the authors’ research
group interested in gamification design for data
literacy. Mainly, we focused on the integration of
one motivational affordance per type to provide a
game-like experience to participants with
different stimuli but keep the same settings and
interface whenever possible to have comparable
versions. More iterations took place among the
first and third authors of this study. We decided
that the motivational affordance should be
represented at the top and bottom of the page (see
gamification placeholder, Figure 1), include
verbal feedback, and updated, by adding one
more, for each page. Regarding challenge-based
gamification, we decided to include badges (i.e.,
bronze, silver, gold, and ruby stars). If the user’s
answers met the criteria for each page, then a new
badge was added in the gamification placeholder.
For the immersion-based version, a series of
avatars related to the sustainable development
agenda pillars (i.e., people, prosperity, planet,
peace, and partnerships) were created, along with
an illustrated story related to the SDGs. Figure 1
shows the illustrated story for a user who has
completed page 3, so three stages of the story have
been opened. The story progresses based on user
correct answers in the application. Social-based
gamification was presented via a competition
element materialized through illustrated quotes
and messages indicating the user’s rank as
compared to others. So, having completed the
tasks for every page, the user discovered or lost an
additional badge (challenge version), contributed
or not to the sustainability goals based on the story
(immersion version), and improved or not their
ranking (social version). The spaces dedicated to
the pictures and texts were blank for the control
version.
      </p>
      <p>A full round in the application. Initially, the
user reads navigation instructions according to the
version that they have been randomly assigned to.
For the challenge-, immersion-, and social-based
gamification there are additional descriptions
regarding the respective elements. Additionally,
for the immersion-based gamification, the user
selects an avatar. Saving their choice, a user
moves to page 1. Every page is composed of 4 to
10 interactive charts, a question for each, and
interactive calculators to help answering the
questions. For each page, participants should
correctly answer an increasing number of
questions to meet the criteria and gain the extra
respective badge, or contribute to the story that
they participate in, or upgrade their rank. The
cumulative number of participants’ correct
answers defines the competitive messages they
receive regarding their rank. A participant needs
to answer all the questions for each page to
proceed to the next one, and all the completed
pages remain available. Feedback regarding
correct answers is available only for the
completed levels, with the respective motivational
affordance per gamification type. A full round is
done when the tasks in page 5 are completed.
Then, the user reaches the post-test. During the
round, users can logout (progress is saved). A user
who has completed a full round cannot participate
again.</p>
    </sec>
    <sec id="sec-10">
      <title>3.2.3. Procedure design and experimental</title>
      <p>The experiments were conducted in the
context of six courses at different schools. All the
participants received the same instructions
regarding the application. However, students in
FT ECE-NTUA, DS MBA-UTH, RM
MBAUTH, and PM UTH had the instructions in Greek
and the incentive for participation was a bonus of
1 out of 10 in the course’s final grade instead of
an equivalent exercise in the final exam. Students
in FDAG TAU and MHT UPR received the
instructions in English and their participation was
mandatory as part of the course. Participants were
instructed to use a computer. They were aware of
the possibility to logout and sign in and the time
available for participation varied per school.
Students in FT ECE-NTUA had a month available
to register and complete a full round, students in
MHT UPR, and DS MBA-UTH, RM MBA-UTH,
and PMUTH had two weeks, and students in
FDAG TAU had one week. These differences are
due to the different course settings.</p>
      <p>All participants had to register and give
informed consent to proceed. Upon their
registration, they had to complete all the pre-test
questions, which were not available afterward.
There was no feedback regarding the pre-test
questions. Having saved their answers, they were
randomly assigned to one of the four conditions,
i.e., control, challenge-, immersion-, or
socialbased gamification, using the sample() function of
the R-base package. Then, participants had to read
the instructions. Additional instructions were
provided to participants based on the version that
they had been assigned to. For example, assigned
participants to the immersion version had to read
additional instructions regarding the game
elements and select one of the avatars.</p>
      <p>Having read the instructions and
independently of the version, participants were
directed to page 1, where they needed to answer
questions based on the provided charts and/or use
calculators. Then, they got feedback about their
choices. Participants assigned to one of the
gamified conditions had one new gamification
element (a badge, a strip of a story, or their
illustrated rank) available at the top and bottom of
every page, based on their performance. The same
process was followed for all the available pages,
having different datasets/charts and tasks per
page, up to page 5. All the previous levels along
with correct answers were available while
participants moved to the next pages. Having
saved their answers on page 5, participants were
directed to the post-test. All participants had to
answer the same post-test questions. All the
previous pages (apart from the pre-test) were
available without the correct answers. Figure 2
illustrates the experimental design and the
procedure that was followed.</p>
    </sec>
    <sec id="sec-11">
      <title>4. Results</title>
      <p>The objective of this study is to present and
evaluate an online application which uses real
worldwide data to teach basic data literacy topics
and investigate the impact of three gamification
types regarding the learning outcomes. Hence, we
collected students’ performance in pre- and
posttests. Student performance for each test was
calculated as the sum of the correct answers.
Considering all the questions as equivalent, the
maximum score per test is equal to the number of
questions, i.e., 30. The overall statistical approach
to this study’s results is divided into two steps.
Initially, the collected data from both pre- and
post-test questionnaires are examined using
descriptive statistics to explore the group means,
standard deviations, and numbers. Figure 3
illustrates the performances of students per test
and treatment and Table 1 presents the descriptive
statistics per group and school, too.</p>
      <p>In terms of an overall evaluation of the
educational application, the mean value of
students’ post-test performance (M=19.03,
SD=5.05) is higher than their pre-test
performance (M=13.24, SD=4.09), as expected.
We conducted a paired t-test, with a confidence
interval equal to 95%. The null hypothesis: H0
equal differences in means is rejected (t = 20.634,
df=180, p&lt;0.001), thus using the suggested
educational application improves mean
performance in the context of data literacy by
43.73%, resulting in a large effect size (d=1.26).</p>
      <p>In order to further examine the differences
between pre- and post-tests in the different
gamification strategies, we opted for
nonparametric tests, due to the violation of the normal
distribution assumption in the groups. A
Wilcoxon Signed-Ranks Test for each type
indicates that the mean post-test ranks were
statistically significantly higher than the mean
pre-test rank for each type of gamification, with a
confidence interval equal to 95%. Table 1 presents
mean values, standard deviations, numbers for
each type, differences in pre- and post-test
performance and the improvement along with
respective Wilcoxon effect sizes.</p>
      <p>Next, the impact of different gamification
types regarding learning outcomes in EDA topics
is examined. Analysis of covariance (ANCOVA)
was chosen to examine the effects of using
different gamification types on student
performance, controlling for initial differences in
the pre-test. However, having different group
sizes and not meeting the assumption of linear
relationship between the dependent variable and
the covariate, we follow the non-parametric
alternative, using the sm and fANCOVA packages
in R (v3.5.3) for validation. Four curves have been
calculated based on polynomial regression with
automatic smoothing parameter selection via
AICC for curve fitting. Based on the comparison
of four non-parametric regression curves, the null
hypothesis “H0: there is no difference between the
4 curves” cannot be rejected (T=21.08, p=0.741).</p>
      <p>Acknowledging non-parametric analysis
limitations, we also conduct a one-way ANOVA
on performance change. Our sample meets the
ANOVA assumption (i.e., normal distribution,
homogeneity of variance, and the observations are
independent of each other). No statistically
significant differences were detected F(3,177)=
2.563, p=0.056. This fact is in line with the
nonparametric analysis, and it implies that all groups
showed a similar learning gain for all the different
gamification types, including the control group,
regarding student performance change.</p>
    </sec>
    <sec id="sec-12">
      <title>5. Discussion and conclusions</title>
    </sec>
    <sec id="sec-13">
      <title>5.1. Discussion</title>
      <p>
        Overall, the results suggest that the use of the
online application improved learning outcomes
regarding data literacy, as investigated in this
study, using interactive charts and tools, with real
data sets related to current societal challenges, i.e.,
COVID-19 and SDGs. Other studies suggest that
learning objectives in the context of data literacy
can be achieved by using data visualization
techniques and statistics as persuasive technology
means, that is as interactive technology that aims
to change a person’s attitudes or behavior [
        <xref ref-type="bibr" rid="ref44">44</xref>
        ].
They can also promote critical thinking among
students [
        <xref ref-type="bibr" rid="ref45 ref46">45,46</xref>
        ] and provide opportunities in
teaching-learning process [
        <xref ref-type="bibr" rid="ref47 ref48">47,48</xref>
        ]. Despite that
the use of persuasive technology, or captology as
is mentioned [
        <xref ref-type="bibr" rid="ref44">44</xref>
        ], is not yet mature in education,
there are some preliminary positive indicators
about its potential on some learning variables such
as attitude and motivation, but further research is
needed [
        <xref ref-type="bibr" rid="ref49">49</xref>
        ]. Hence, the noted improvement of all
the versions, control included, could be an effect
of the interactive charts and tools provided and the
chosen thematic areas, which could impact on
motivation positively and eventually learning.
This finding could be in accordance with [
        <xref ref-type="bibr" rid="ref35">35</xref>
        ],
who examine the effects of data visualization as a
persuasive visualization tool that might positively
impact people’s attitude and memorization or
even improve accuracy as in a Bayesian reasoning
problem [
        <xref ref-type="bibr" rid="ref36">36</xref>
        ]. However, further empirical
research is needed in this area [
        <xref ref-type="bibr" rid="ref35">35</xref>
        ].
      </p>
      <p>
        Another important finding is that the
integration of different gamification types did not
result in statistically significant differences on
students’ learning outcomes. Despite the
mentioned positive effects of gamification in
education [
        <xref ref-type="bibr" rid="ref10 ref8">10, 8</xref>
        ], there are a few studies
commenting on the potential negative effects of
gamification [
        <xref ref-type="bibr" rid="ref37">37</xref>
        ]. Based on [
        <xref ref-type="bibr" rid="ref37">37</xref>
        ], 35% of the
reviewed papers mentioned indifference as an
effect, when gamification did not impact for better
nor for worse. Our results are in line with [
        <xref ref-type="bibr" rid="ref50">50, 51</xref>
        ],
where there was no significant impact of
gamification on e-learning interventions on
students’ performance, even though in these
studies the participants’ initial motivation was
higher and the described interventions lasted
longer. In our study, the novelty effect or research
fatigue might contribute also to this lack of effect
on performance since most of the students
completed the full activity, on average, in two
hours, rather than logging out and signing in.
5.2.
      </p>
    </sec>
    <sec id="sec-14">
      <title>Limitations</title>
      <p>
        There are some limitations regarding the
design of the application. All the versions, control
included, contain interactive charts, icons/emojis,
and colorful buttons. The control version does not
include any gamification, but it might be playfully
framed given its interactivity, diverse colors, and
a user-friendly design. So, even the control
version might afford a playful experience. Even
though badges, avatars and a story, and
competition are representative of the challenge-,
immersion-, and social-based gamification [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ],
our results are limited regarding the
implementation, the sample, and the described
context.
      </p>
      <p>Another limitation refers to the sample and the
procedure of the experiments. The sample sizes,
the difference in students’ schools, and years of
study within the students’ distribution into
different conditions might affect the homogeneity
of slopes between pre- and post-test’ s
performances. Since a non-parametric analysis
was conducted, the validity of the results is not
affected. The difference in incentives needs to be
mentioned, as well. Students in FT ECE-NTUA,
RM MBA-UTH, DSMBA-UTH, PM UTH
received 1 point out of 10 as a bonus in their
grade, instead of an equivalent exercise at the end.
However, students in FDAG TAU and MHT UPR
participated in the application as part of
mandatory assignments to successfully pass the
course. Finally, despite the difference in the
instructions about the available time to complete
a full round, all students but one completed a full
round in a maximum of three days. This study
focuses only on the impact of a web-based
application on data literacy and the comparison
among different gamification types. However,
both pre- and post-test questionnaires comprise
more questions than the knowledge questions,
which might lead to research fatigue. A larger
sample is suggested, and completing a full round
during three days, even though the noted
improvement shows the potential of this approach.
5.3.</p>
    </sec>
    <sec id="sec-15">
      <title>Conclusions</title>
      <p>In our study, a (gamified) application was
designed and implemented to teach data literacy
and compare the impact of different gamification
types on learning outcomes. Our results indicate
an average of 43.73% improvement in learning
outcomes and suggest optimism regarding the
contribution of interactive data visualization,
interactive tools, and a friendly user interface in
improving data literacy. However, we should be
more skeptical about the integration of
gamification when there is already a system with
these characteristics as a basis. Employing a larger
sample of the general public will strengthen the
results and support data literacy teaching. In
addition, investigating gameful experience
constructs and connecting the used gamification
features with the improvement in specific learning
outcomes and data literacy topics will provide
insightful perspectives regarding the impact of
gamification design choices in data literacy.</p>
    </sec>
    <sec id="sec-16">
      <title>6. Acknowledgements</title>
      <p>This work has received funding from the
European Union’s Horizon 2020 research and
innovation program under the Marie
SklodowskaCurie, grant agreement No 840809, the Academy
of Finland Flagship Program (337653
ForestHuman-Machine Interplay (UNITE)) and the
Nessling Foundation (project No 202100217).</p>
    </sec>
    <sec id="sec-17">
      <title>7. References</title>
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