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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Evaluating an immersive learning toolkit for training psychomotor skills in the fields of human-robot interaction and dance.</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Khaleel Asyraaf Mat Sanusi</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Daniel Majonica</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Patrick Handwerk</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Suhana Biswas</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Roland Klemke</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Cologne Game Lab, TH Köln</institution>
          ,
          <addr-line>Cologne</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Open University of the Netherlands</institution>
          ,
          <addr-line>Heerlen</addr-line>
          ,
          <country country="NL">The Netherlands</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>RWTH</institution>
          ,
          <addr-line>Aachen</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Developing immersive learning environments for psychomotor skills training typically demands significant time and efort. Immersive training toolkits enable the development of virtual learning environments, incorporating interactive game elements and learning materials to enrich the learning process. Such toolkits have found extensive use in classroom settings; however, their application in the psychomotor domain remains largely unexplored. This paper conducts an evaluation of IMPECT, a training toolkit designed for teaching psychomotor skills within immersive learning environments, focusing on two distinct scenarios: human-robot interaction and dancing. The study gathers survey data to assess the system's usability and incorporates participant suggestions, which are subsequently analyzed and discussed. The initial study results demonstrate the training toolkit's potential applicability across diverse psychomotor domains.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;immersive learning environments</kwd>
        <kwd>toolkit</kwd>
        <kwd>human-robot interaction</kwd>
        <kwd>dance</kwd>
        <kwd>system usability</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        Achieving proficiency in psychomotor skills necessitates deliberate practice and technique,
typically taught within a physical context. These skills demand physical execution, often
through repetitive practice, to the point where the learner’s muscle memory becomes trained,
automating the muscle movements and enabling smoother, more natural execution [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. That
being said, the presence of teachers is essential for instructions and feedback provision. Such
learning components ensure that movement errors can be promptly identified and corrected,
leading to improved performances [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
      <p>
        Immersive learning systems are educational tools that are typically supported by immersive
technologies such as virtual reality (VR), augmented reality (AR), and mixed reality (MR),
allowing the creation of immersive learning environments (ILEs) to provide realistic teaching
and learning experiences in a virtual world [
        <xref ref-type="bibr" rid="ref3 ref4">3, 4</xref>
        ]. In addition, sensor technologies are used for
the collection of multimodal data to track learners’ behavior and performance, further aiming to
improve the learning outcome [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. By exploiting the multimodal data, instruction and feedback
components can be provided in a multimodal manner (e.g., visual, auditory, haptic), conveying
more and richer information to the learner [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>
        An immersive learning toolkit refers to a set of resources, software, and hardware designed
to facilitate the creation, implementation, and management of learning sessions or educational
materials in virtual worlds. It includes various resources like learning materials, exercises,
assessments, and game-world interactive elements, further enhancing the learning experience [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
In recent years, immersive learning toolkits have been vastly developed and widely used for
classroom activities [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. However, such toolkits are still yet to be explored in the psychomotor
domain for skills training.
      </p>
      <p>This paper presents an evaluation of the Immersive Multimodal Psychomotor Environments
for Competence Training (IMPECT) toolkit in two specific application areas within the
psychomotor domain: human-robot interaction (HRI) and dance. The assessment encompasses the
current state of prototypical development, usability scores, and recommendations for
enhancements drawn from the survey data.</p>
      <p>This article is structured as follows. Section 2 describes the proposed toolkit. Section 3
explains the methodology and shows the results of the collected data. We summarize and
discuss the findings of the study in Sections 4 and 5, respectively. Lastly, limitations and future
work are described in Section 6.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Immersive Multimodal Psychomotor Environments for</title>
    </sec>
    <sec id="sec-3">
      <title>Competence Training (IMPECT)</title>
      <p>IMPECT represents a versatile training toolkit that facilitates the development of ILEs, leveraging
sensors and immersive technologies to cater to various psychomotor skills training needs.
Acknowledging that diferent domains might call for specific technologies and learning materials,
this toolkit empowers developers, researchers, and educators to create customized ILEs tailored
to their psychomotor skills training objectives.</p>
      <sec id="sec-3-1">
        <title>2.1. IMPECT Clients</title>
        <p>In the context of this paper, two client applications were developed using Unity, exploring the
domains of HRI and Dance. Both are designed for visualizing and providing feedback from the
IMPECT-server (see Section 2.2). In order to do so, an established connection is made between
both clients and the server to ensure that feedback can be triggered by human experts. Since
the development of skills varies between the two cases, diferent technologies are utilized. The
following subsections introduce the two clients, namely IMPECT-HRI and IMPECT-Dance.</p>
        <p>Legend
REA: Robot
Evaluation
Algorithm
oFnoMM:isFteaekdeback
Feedback
Processing
IMPECT Server (Python)</p>
        <p>FoM Templates (n = 9)
FoM 1
FoM …</p>
        <p>FoM 2</p>
        <p>FoM n
Input</p>
        <p>
          IMPECT-HRI Client (C#)
The IMPECT-HRI tool is an AR application created using IMPECT. As sensors, it uses the
gesture detection of the Hololens. Inside the tool, the user can autonomously interact with the
UI components that are presented in the AR environment. Whenever an interaction through
the system happens, it will get logged and analyzed. The Robot Evaluation Algorithm (REA)
on the AR hardware takes the current state of the environment and the interaction with the
system into account and calculates a decision. This decision runs through the expert who
also observes the learner doing the task. If the learner did a mistake or something unexpected
happens, the expert can react and send feedback to the IMPECT server. On the server, multiple
pre-determined "Feedback on the Mistake" (FoM) can be selected. The calculated decision by
the REA gets transported to the physical robot. This physical robot takes in the decision and
visually displays its decision to the learner. The feedback on the other hand gets sent through
the AR environment and gets displayed in the form of visual and auditory feedback to the
learner. This feedback is displayed either through text, sound, or both. This whole process can
be seen summarized in Figure 1.
The IMPECT-Dance tool is a desktop-based application that utilizes the Kinect’s depth camera
sensor, focusing on basic dance movements. Additional feedback and UI components were
implemented in the tool, extending the previous version that concentrate on basic exercise
routines [
          <xref ref-type="bibr" rid="ref9">9</xref>
          ]. For visualizing the learning environment with its feedback components, an external
screen is used.
        </p>
        <p>Figure 2 shows the system architecture of the IMPECT-Dance tool. The visualization of the
learners is captured by the Kinect camera, mirroring them and allowing them to see themselves
when performing the dance movements. The human learning elements comprise instructional
Legend
FoM: Feedback
on Mistake</p>
        <p>E: Exercise
Feedback</p>
        <p>Logic
IMPECT Server (Python)
FoM Templates (E = 1...5)</p>
        <p>FoM E.1
FoM E.3</p>
        <p>FoM E.2
Input</p>
        <p>IMPECT-Dance Client (C#)
objects and feedback objects. The instruction objects consist of a Video Tutorial of the expert
performing a full-dance routine which is segregated into five diferent exercises. The presence
of the Expert Avatar aims to assist the learners by performing the animation of the five exercises
procedurally. The animations were pre-recorded by the expert in the video with the use of a
motion capture system for recording the dance movements.</p>
        <p>The feedback elements consist of both visual (text and highlighted-joint) and auditory
(sound and speech) modalities. For visual feedback, the specific joint/s of the avatar will be
highlighted in red/orange color, which corresponds to the mistake. Additionally, text feedback
is given in a way to guide the learner in correcting the mistake. For auditory feedback, a 90
BPM metronome sound is played throughout the session to assist the learner in following the
beat. Furthermore, speech feedback is played when a mistake is detected, corresponding to the
same message as the text feedback. In the context of our paper, the expert drives the simulation
by observing the movements of the learner and selecting the corresponding FoM template when
a mistake is detected.</p>
      </sec>
      <sec id="sec-3-2">
        <title>2.2. IMPECT Server</title>
        <p>The server was implemented using Python in order to provide full control for the expert/teacher
in navigating the learning session and sending FoM templates according to the mistakes that have
been detected. The user interface (UI) is designed to be straightforward for the teacher, consisting
of tabs and buttons that would steer the sub-sessions and trigger feedback, respectively. Each
application comprises instructions and FoM templates that can be selected and sent to the
respective client. For each FoM template, several feedback types (UI or game-world objects) and
modalities (visual and/or auditory) are clustered, allowing the teacher to prompt the learner by
choosing the specific FoM that corresponds to the detected mistake.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>3. Methods</title>
      <sec id="sec-4-1">
        <title>3.1. Research Design</title>
        <p>Two distinct events were utilized to evaluate both IMPECT tools, with a total of 29 participants
attending the two sessions. To minimize any potential disruptions and uphold the element
of surprise for each study, the setup for both experiments took place at separate locations.
Following a brief introduction, the participants were asked to read the information letter and
provide their consent by signing the form.
3.1.1. HRI
Before interacting with the system, the learner first had to be introduced to the game which is
being played cooperatively with the robot. It involves a physical robot, an AR environment,
and custom playing cards. Instructions are provided via video and feedback is provided in the
form of text and sound. The game rules are as follows:
• Only go through rooms that are connected by a door.
• In order to move to a diferent room; first, click the virtual card, then, turn the physical
card
• In robot rooms; first, click the virtual card, second, wait for the robot’s decision, third,
make your final decision, then, turn the physical card
• Find the keycard inside a hidden box (hidden object card) to open the last door to the
engine room.</p>
        <p>• A maximum of 15 turns to traverse the maze.</p>
        <p>The protocol for communicating the game rules to participants within the AR ILE employs
instructional videos comprising both visual and auditory components. This video is being
played at the beginning of the research study. The game progression can be summarized as
follows: 1) The player first decides which room to enter on the virtual grid. This choice is made
within the AR environment by selecting a room. 2) Some rooms are labeled as "robot rooms."
Within these rooms, the robot’s decision-making algorithm (REA) makes decisions based on
the ongoing game situation. Once the REA decides, the player must reconfirm their choice
of room within the virtual grid. 3) Once the virtual room choice is confirmed, the player is
required to flip the corresponding physical card. An essential aspect of completing the game
involves locating a hidden box, symbolized by a concealed card somewhere within the maze.
Successfully finding and using this hidden card is necessary to conclude the game.</p>
        <p>The REA uses a path-finding algorithm to navigate the maze. However, there are modifications
to the algorithm for diferent scenarios, such as when the learner has turned left, REA always
agrees with the learner’s choice. On the last decision, REA deliberately disagrees with the
learner’s choice to observe their reactions to diferent outcomes.
3.1.2. Dance
The full-dance routine was segregated into five diferent exercises (Exercises 1 to 5), which the
learner needs to complete in a procedural manner. The performance is observed by a
sportsscientific expert who critically rated the users’ motion executions and provided immediate
relevant feedback (either praising or corrective) by selecting the FoM template from the IMPECT
server accordingly to the mistake that was detected. We listed three common beginner mistakes
for each exercise (15 in total) in the server, classifying them as mistake IDs. Each FoM template
corresponds to the designated mistake ID, consisting of several feedback types and modalities.
For instance, "FoM 1.2" happens when the learner’s elbows are too low, therefore, elbows need
to be highlighted (visual), text (visual), and speech (auditory) feedback are given to the learner.</p>
        <p>The study comprises two sessions: learning and challenge. The learning session allows
the learner to perform the movements procedurally and receives feedback when mistakes are
detected. The challenge session, however, requires the learner to perform the full-dance routine
without receiving any feedback. In total, 21 people participated in the dance study.</p>
      </sec>
      <sec id="sec-4-2">
        <title>3.2. Instruments</title>
        <p>
          To assess the usability of both prototypes, the System Usability Scale (SUS) was employed.
This 5-point Likert scale ofers a comprehensive evaluation of subjective user assessments,
encompassing efectiveness, eficiency, and satisfaction aspects of the systems [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ]. Moreover,
the participants were presented with five open-ended questions, inviting their valuable input
and suggestions for future improvements to be incorporated in subsequent iterations of the
prototypes.
        </p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>4. Results</title>
      <sec id="sec-5-1">
        <title>System’s Usability Scale</title>
        <p>In Table 1, we observed that the SUS scores for IMPECT-HRI and IMPECT-Dance are 55.95 and
74.88, respectively. Overall, the SUS score for both prototypes has a mean score of 69.66, which
is slightly above the average score (68).</p>
      </sec>
      <sec id="sec-5-2">
        <title>Suggestions and Improvements</title>
        <p>Figure 3 shows the three most suggested components by the participants. In the case of HRI
(Figure 3a), "Hints" (43%) is considered to be the most crucial component that needs to be
implemented to the IMPECT-HRI tool, followed by "Step-by-step instruction" (23%), "Active
feedback" (14%), and "Adequate virtual-physical objects" (14%). For the dance case (Figure 3b),
"Synchronized metronome" (33%) was the most suggested component for the IMPECT-Dance
(a) IMPECT-HRI
(b) IMPECT-Dance
tool, followed by "Superimposed direct feedback" (27%), "Clearer speech feedback" (20%), and
"Bigger screen" (20%).</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>5. Discussion and Conclusion</title>
      <p>Based on the collected data, we found that both prototypes received a relatively positive
usability rating, with a SUS score of 69.66. Although this score is slightly higher than the
threshold, it indicates that participants generally perceived the prototypes as reasonably usable
and user-friendly. Notably, in the case of the dance prototype, it scored higher on the SUS
scale, which could be attributed to the simplicity of tasks involved. The dance movements
integrated into the system were repetitive and easier to perform compared to the HRI case,
which required participants to engage in more complex tasks. The familiarity factor also played
a role. Learning dance skills is more common and accessible compared to the relatively novel
concept of interacting or collaborating with robots. Additionally, as the prototypes involved
mixed-reality glasses and robot interaction, which are not widely accessible in society, many
participants might not have been familiar with the gestures needed to navigate the learning
environment, contributing to the perceived complexity of handling the prototype.</p>
      <p>For IMPECT-HRI, the survey highlighted the need for a hints system as the prototype’s
instructions before the card game were unclear, causing delays in the current session.
Furthermore, participants suggested video instructions delivered in a step-by-step manner. Due to the
passiveness and low level of feedback immediacy, the participants proposed the feedback to be
more active and immediate. Interestingly, some participants pointed out a weak UI/UX
connection between the virtual and physical elements, urging improvements for better integration and
meaningful learning outcomes.</p>
      <p>Regarding IMPECT-Dance, the most crucial suggestion was to address the synchronization
issue between the metronome and the dancing avatar, which became increasingly unaligned
during longer sessions. Participants also found the coexistence of both the live view and the
expert avatar confusing, leading to the recommendation of superimposed feedback on the live
avatar, based on the participant’s movements. The audio feedback was perceived to be slightly
inaudible, prompting the implementation of speech feedback to make it more easily audible
to participants. Lastly, participants expressed the need for a larger, higher-quality screen to
enhance the visualization of the environment during training.</p>
      <p>This paper presents a comprehensive evaluation of the IMPECT training toolkit, focusing
on two application areas within the psychomotor domain: human-robot interaction (HRI) and
dance. The assessment encompasses three main aspects: the current state of prototypical
development, the usability scores acquired, and the recommendations for enhancements based
on the survey data. The questionnaire results served as valuable feedback to the researchers
and developers, guiding potential user-specific adaptations and future improvements.</p>
      <p>In summary, this paper ofers both theoretical and practical implementations. From a
theoretical standpoint, it introduces the concept of FoM templates, comprising diverse feedback types
that can be utilized for skills training and expanded with additional components tailored to
specific use cases. On the practical side, the toolkit’s application extends to various psychomotor
domains, with the possibility of further exploration through the addition of more use cases to
enhance its scalability and flexibility.</p>
    </sec>
    <sec id="sec-7">
      <title>6. Limitations and Future Work</title>
      <p>During the study, several shortcomings came to light. Firstly, we faced limitations in
experimenting with all workshop participants due to the time constraints of the workshop itself.
Furthermore, some participants encountered dificulties with the visualization of the
environment because of inadequate brightness from the projector. The technology utilized also had its
limitations, afecting the accessibility of the environment. Additionally, a participant with poor
eyesight experienced challenges in interacting with the environment efectively.</p>
      <p>In future endeavors, there is room for enhancing both prototypes by incorporating a wider
range of feedback elements, including various types and modalities, to foster more efective
and meaningful learning outcomes. Consideration can also be given to integrating artificial
intelligence technology, enabling performance analysis and feedback provision in an automated
manner. Furthermore, it is worth exploring additional psychomotor use cases alongside their
respective technologies and FoM templates. This approach aligns with the overarching concept
of the IMPECT training toolkit, designed to cater to diverse psychomotor domains and ofer a
comprehensive solution for training and competence development.</p>
    </sec>
    <sec id="sec-8">
      <title>7. Acknowledgments</title>
      <p>This work was funded by the German Federal Ministry of Education and Research (BMBF)
within the project “MILKI-PSY”1 under the project ID: 16DHB4015.</p>
    </sec>
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