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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>ChildCIdb_v2: A Longitudinal Database for Children-Computer Interaction on Mobile Devices</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Juan Carlos Ruiz-Garcia</string-name>
          <email>juanc.ruiz@uam.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ruben Tolosana</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Ruben Vera-Rodriguez</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Aythami Morales</string-name>
          <email>aythami.morales@uam.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Julian Fierrez</string-name>
          <email>julian.fierrez@uam.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Javier Ortega-Garcia</string-name>
          <email>javier.ortega@uam.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jaime Herreros-Rodriguez</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Biometrics and Data Pattern Analytics (BiDA) Lab, Universidad Autónoma de Madrid</institution>
          ,
          <country country="ES">Spain</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Hospital Universitario Infanta Leonor</institution>
          ,
          <addr-line>Madrid</addr-line>
          ,
          <country country="ES">Spain</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Children are increasingly exposed to mobile devices on a daily basis. This opens the doors to the proposal of novel methods to automatically quantify the correct motor and cognitive development of children through the use of mobile devices. This study presents ChildCIdb_v2, a longitudinal database for ChildComputer Interaction (CCI) on mobile devices. ChildCIdb_v2 contains 615 diferent children from 18 months to 8 years old, and 6 diferent acquisition sessions carried out since 2020. In total, there are over 2.1K children acquisitions using both a stylus or the nfiger to interact with the touch screen. Preliminary experiments confirm the potential of ChildCIdb_v2 to conduct longitudinal analyses of the children, for example, early detection of children with motor/cognitive disorders.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;child-computer interaction</kwd>
        <kwd>childcidb</kwd>
        <kwd>longitudinal analysis</kwd>
        <kwd>e-health</kwd>
        <kwd>e-learning</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        The exposure of children aged 0-8 years to mobile devices has increased dramatically in recent
decades (11 times from 2011 to 2020 [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]) due to technological innovation [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ]. They are growing
up in environments overloaded with multiple digital technologies (e.g., smartphones, tablets,
smart TVs, smartwatches, etc.) [
        <xref ref-type="bibr" rid="ref3 ref4">3, 4</xref>
        ].
      </p>
      <p>
        Despite this technological evolution, the assessment of the correct motor and cognitive
development of children is still evaluated using traditional approaches that are manual,
timeconsuming, and provide qualitative results that are dificult to interpret. This is one of the
main motivations of our ChildCI research project [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]: the proposal of automatic methods to
quantify the motor and cognitive development of the children through the interaction with
mobile devices, using both the stylus [
        <xref ref-type="bibr" rid="ref6 ref7 ref8">6, 7, 8</xref>
        ] and the finger [
        <xref ref-type="bibr" rid="ref10 ref9">9, 10</xref>
        ].
      </p>
      <p>1–6</p>
      <sec id="sec-1-1">
        <title>ChildCIdb_v2 Database</title>
        <p>January 2020
October 2022
Emotional State
Self-Assessment</p>
      </sec>
      <sec id="sec-1-2">
        <title>Block 1: Touch Analysis</title>
        <p>Test 1(-3T0aspeacnodndRsemacatxio.)n Time Te(s3t02s-eDcorangdsanmdaDxr.)op</p>
      </sec>
      <sec id="sec-1-3">
        <title>Block 2: Stylus Analysis</title>
        <p>Test 5 - Spiral Test
(30 seconds max.)
From 18 Months
to 8 Years Old</p>
        <p>Test 3 - Zoom In
(30 seconds max.)</p>
        <p>Test 4 - Zoom Out
(30 seconds max.)</p>
        <p>Test 6 - Drawing Test
(2 minutes max.)</p>
        <p>
          This paper presents ChildCIdb_v2 database, a longitudinal extension of the first release of
ChildCIdb_v11[
          <xref ref-type="bibr" rid="ref5">5</xref>
          ]. To the best of our knowledge, this is the largest publicly available database
to date for research in CCI. In particular, ChildCIdb_v2 contains 6 diferent acquisition sessions
carried out since 2020 in collaboration with the school GSD Las Suertes in Madrid, Spain.
Children aged 18 months to 8 years are acquired while interacting with a tablet device using
ifnger and stylus tools. According to the Spanish education system, children are grouped into 7
diferent educational levels (Groups 2 to 8). During the acquisition process, children perform 6
diferent tests grouped into 2 main blocks: i) touch, and ii) stylus. Fig. 1 provides a graphical
representation of the acquisition. Each test requires diferent motor and cognitive skills to be
completed correctly within a time range. Next, we briefly describe each of the tests [
          <xref ref-type="bibr" rid="ref5">5</xref>
          ]:
• Block 1: Touch Analysis
– Test 1 - Tap and Reaction Time: there are 6 burrows and 1 mole. Children must
tap the mole using only one finger. Then it disappears and reappears in another
burrow up to 4 times (30 seconds max).
– Test 2 - Drag and Drop: there is a carrot and a rabbit on the screen. Children must
tap the carrot and swipe it to the rabbit using only one finger (30 seconds max).
– Test 3 - Zoom In: there is a small rabbit and 2 circles of diferent sizes. Children
must enlarge the rabbit and put it between circles using 2 fingers (30 seconds max).
– Test 4 - Zoom Out: it is very similar to Test 3, but this time the rabbit must be
reduced. 2 fingers are needed again (30 seconds max).
• Block 2: Stylus Analysis
– Test 5 - Spiral Test: using a pen stylus, children must go across the inner part of
the black spiral, from the central to the outer part (30 seconds max).
– Test 6 - Drawing Test: the outline of a tree appears on the screen. Children must
color the whole tree using a pen stylus (2 minutes max).
        </p>
        <p>In addition, other children’s metadata is also collected such as emotional state, previous
experience with mobile devices, prematurity (&lt; 37 weeks gestation), attention deficit/hyperactivity
disorder (ADHD), date of birth, gender, handedness, and academic grades.
2. ChildCIdb_v2: Longitudinal Database
ChildCIdb_v2 contains data from 615 diferent children in total. In particular, 6 data acquisitions
have been carried out in the last 4 academic years, comprising over 2.1K children’s sessions
and over 12.6K children’s interactions with mobile devices (each session comprises 6 tests). The
same children have been acquired along time until they reach the highest educational level
(Group 8). In addition, new children from the lowest educational levels were also captured
in each acquisition (Groups 2 to 4). Table 1 describes the total number of children collected
for each age group and data acquisition, as well as the gender information (about 50% of the
children are male/female).
)
(%60
y
t
i
l
a
u
tQ40
s
e
T
20
0
Group 2
(18M-2Y)
Group 3
(2Y-3Y)
Group 4
(3Y-4Y)
Group 5
(4Y-5Y)
Group 6
(5Y-6Y)
Group 7
(6Y-7Y)
Group 8
(7Y-8Y)
Adults Group
(25Y-65Y)
Test 6 - Drawing Test
51
34
34
34
18
Group 2
(18M-2Y)</p>
        <p>Group 3
(2Y-3Y)</p>
        <p>Group 4
(3Y-4Y)</p>
        <p>Group 5
(4Y-5Y)</p>
        <p>Group 6
(5Y-6Y)</p>
        <p>Group 7
(6Y-7Y)</p>
        <p>
          G(7roY-u8pY8) Ad(2u5ltYs-6G5roYu)p
3. Preliminary Experiments
In [
          <xref ref-type="bibr" rid="ref11 ref5">5, 11</xref>
          ] we performed the first experiments over a previous version of ChildCIdb. We
demonstrated the high discriminative power for the task of age group detection (over 93% accuracy),
and the inherent applicability of the tests to other research problems around e-Learning [
          <xref ref-type="bibr" rid="ref12 ref13">12, 13</xref>
          ]
and e-Health [
          <xref ref-type="bibr" rid="ref14 ref15">14, 15</xref>
          ].
        </p>
        <p>We provide next a preliminary experiment using ChildCIdb_v2. Fig. 2 shows the test quality
(%) obtained for Test 6 (Drawing Test) for each age group against a control group of 70 adults
with all their motor and cognitive skills fully developed. The more colored the tree is, the higher
the test quality will be. Coloring out is penalized.</p>
        <p>As can be seen in Fig. 2, the higher the level group is, the higher the test quality is, showing
better motor and cognitive skills. In general, children at higher educational levels (Groups 7 and
8) obtain a test quality very similar to that of an adult. However, in the lower groups, where
children still have to develop the motor and cognitive skills needed to complete Test 6 correctly,
the test quality is lower and with higher variability.</p>
        <p>
          To conclude the paper, ChildCIdb_v2 enables longitudinal studies to advance in: i) measuring
the motor and cognitive development of children through the use of mobile devices to detect
delays or dificulties during the development, enabling early interventions [
          <xref ref-type="bibr" rid="ref16 ref17">16, 17</xref>
          ]; and ii)
ifnding relationships between children’s interaction with mobile devices and other metadata
stored in ChildCIdb (academic grades, prematurity, etc.), among others.
        </p>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>4. Acknowledgments</title>
      <p>This work has been supported by projects: INTER-ACTION (PID2021-126521OB-I00
MICINN/FEDER) and HumanCAIC (TED2021-131787B-I00 MICINN). J.C. Ruiz-Garcia is supported
by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement
with Autonomous University of Madrid in the line Encouragement of the Research of Young
Researchers, in the context of the V PRICIT (Regional Programme of Research and Technological
Innovation). This is an on-going project carried out with the collaboration of the school GSD
Las Suertes in Madrid, Spain.</p>
    </sec>
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