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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>Potsdam, Germany, September</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Sensor Data for Learning Support: Achievements, Open Questions and Opportunities</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Haeseon Yun</string-name>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Monika Domanska</string-name>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Albrecht Fortenbacher</string-name>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Mina Ghomi</string-name>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Niels Pinkwart</string-name>
        </contrib>
      </contrib-group>
      <pub-date>
        <year>2016</year>
      </pub-date>
      <volume>11</volume>
      <issue>2016</issue>
      <fpage>28</fpage>
      <lpage>39</lpage>
      <abstract>
        <p>A recent trend in the field of learning analytics is to use sensor data about learners to support self-regulated learning. Combining personal, sensor based data with log data derived from a learning environment is a very promising approach, but also poses big challenges for the design of learner models and learner interaction methods, for the interpretation techniques of such data, and on applicable learning scenarios with their ethical and privacy demands. This paper provides a brief review of the emerging field of sensory aided learning analytics, and presents first results towards modeling and developing solutions for sensor-based adaptive learning in different learning contexts.</p>
      </abstract>
      <kwd-group>
        <kwd>sensors</kwd>
        <kwd>smart wearable devices</kwd>
        <kwd>learning analytics</kwd>
        <kwd>adaptive learning</kwd>
        <kwd>self-regulated learning</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>Learning analytics is becoming a multi-faceted field. One recent direction that research
in learning analytics has taken is to shift the focus away from the traditional
perspectives of institutions and instructors towards more user-centric views and methods in which
learning analytics has the purpose of supporting adaptive and self-regulated learning.
Another recent trend in educational data mining and learning analytics that goes along with
the widespread availability and use of sensor technology, increasingly also integrated into
smart wearable devices, is to investigate the extent to which this sensor data about learners
can be used to support learning processes. Here, research is needed on applicable methods
for learning analytics, on technical requirements and design options for systems providing
learner support via feedback, on algorithms for recommendation or adaptiveness, and on
interpretation methods and principles of personal sensor data in a learning context.
In educational psychology, factors such as learner’s motivation, time management skills
and metacognitive skills have been investigated in various studies. Some of these have
found correlates for these factors, thus linking them to measurable variables like clicks,
postings, messages, views, writes, likes and other types of learner behavior in online
learning environment. In the psychology and medical literature, there is also evidence on the
correlation between certain types of data that can be collected with sensors (e.g. heart
rate, or skin conductance) and higher-level states of persons (e.g., anxiety). In the field of
learning analytics, one typical goal is to use records of learner behavior and state (either
Sensor Data for Learning Support 29
online or offline) and to feed this into learning analytic algorithms in order to derive an
educational meaning or decide whether to adapt a learning technology to the user.
However, relating a specific learner’s behavior and state, represented via complex interleaved
concepts such as emotion, cognition, motivation or meta-cognition (in addition to user
actions) has not yet been thoroughly investigated by either discipline - especially not with
the perspective of feeding this information back to the user in order to support his
selfregulatory processes. This paper addresses this research gap. While we are currently far
from solving the problems stated above, the first goal of this present work is to review
some of the pertinent literature and provide a categorization of sensors by learning domain
(section 2). Based on the argument that a suitable technical framework for learning
analytics based on data collected by multiple sensors is currently lacking, section 3 of this paper
presents a first prototype of a sensor learning device and discusses some findings from a
pilot study conducted with this device. This section also contains possible industrial and
university based usage scenarios for a sensor based learning analytics framework (and the
corresponding technical device). We conclude section 3 with discussions on ethical and
privacy aspects of such scenarios.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Review on Sensor Data for Learning</title>
      <p>Learning analytics allows learning data to provide a more accurate description of the
learning context, learning endeavor, and might result in a better learning experience design. The
observable behavior of students can be utilized to achieve a better learning environment.
In education, sensor data refer to observable data in online learning environment. The
quantifiable data such as log-in duration, log-in and -out timestamp, number of views,
duration of views, frequency of log-in, and clicking point and qualitative data such as text
analysis, social interaction analysis and learning path detection have been used to interpret
a learning state. The approach to relate the measurable data from the online learning
environment with theoretical background requires sophisticated interpretation [JKY14]. For
example, an overall log-in time to an online learning environment could be interpreted as
the total studying time, which is used as an indicator to explain learning performance. In
the literature [PAI01] [DG05] [KKP09], data have been paired up to describe and suggest
a better online learning environment design. Examples are: login frequency and course
satisfaction, login frequency and attendance rate, participation frequency and learning
outcome.</p>
      <p>Learning analytics considers recorded (log) data from online learning environments that
can be read and processed by machines [Pr16]. This approach limits the learning
environment to an online learning environment, and there still exist opportunities for further
enhancement by providing rationales between measured data and educational theories.
Research on sensors provides new chances for learning environment design, since modern
sensors are affordable and provide elaborate physiological data; studies on sensors are well
advanced to support learners’ learning activities [Ma16]. Sensors can detect extrinsic
contexts, e.g. position, time and environmental values, whereas an intrinsic context is personal
to a learner, e.g. motivation or cognition [Th12]. With sensor data available, the obtainable
data is not limited to offline settings, but also includes a learner’s state and condition during
online learning. This implies that face-to-face and online learning environments can
benefit by including learners’ physiological data which are detected by hardware sensors. In
the research related to sensors, gaze awareness tools, EEG, eye tracking and accelerometer
have been utilized to facilitate learning and teaching [Pr16]. Sensors for learning support
can be categorized by learning domains which were introduced by Bloom and colleagues
[Bl56] and thoroughly described in [Sc15]. In Tab. 1, we focus on sensors pertinent for our
learning domain.</p>
      <p>Sensors
While compass, GPS, gyroscopes and inertial sensors may be utilized for the detection
of psychomotor activities, accelerometers are most widely utilized to monitor physical
movement, analyzes the position of the activity and a specific behaviors [AS02] [BK06]
[GLJ09] [Hi11] [He06]. Heart-rate monitors are used to analyze the vital state of a person
related to sports, health and everyday activity [Pe05] [SF12] [Va10]. For emotional
detection, galvanic skin conductance (electrodermal activity) sensors have been utilized for
monitoring health and learning situations [Ar09] [Ca13]. Data from air pollutants sensors,
humistors or thermometers may also be valuable to detect environmental values like
quality of the air of the confined space, humidity level and the actual temperature in a learning
space.
3</p>
    </sec>
    <sec id="sec-3">
      <title>Learning Analytics for Sensor-Based Adaptive Learning</title>
      <p>The review in the previous section shows that, while sensor data is increasingly being used
in educational technology and several Learning Analytics methods include feedback to
the learner (as opposed to feedback to the teacher) as a central mechanism, approaches
Sensor Data for Learning Support 31
that combine these two aspects are surprisingly rare. Currently, little evidence concerning
the benefits (and possible drawbacks and problems) of using sensor collected data to
provide users with adaptive feedback on their learning processes is available, and integrated
technical solutions that are capable of handling multiple sensors while at the same time
allowing students to interact and explore the (pre-processed and analyzed) sensor data are
scarce.</p>
      <p>In the following of this section, we propose a technical approach for collecting and
processing learner data, followed by a spectrum of scenarios for making use of this data
collection approach effectively in various educational settings, covering formal as well as
informal ones. We conclude this section with some remarks on privacy and ethical issues
that the scenarios raise.
3.1</p>
      <sec id="sec-3-1">
        <title>Prototype of a Sensor Device</title>
        <p>As part of a feasibility study, we assembled a prototype of a sensor device with
commercially available sensors, which can prospectively indicate learning domains (cognitive,
affective and psychomotor). Among the sensors listed in Tab.1, we have chosen the three
sensors electrodermal activity sensor (EDA), heart rate sensor (HR) and an accelerometer
as shown in Abb. 1.</p>
        <p>Abb. 1: Experiment setting for emotional intelligence with EDA sensor (prototype 1)
The electrodermal activity is measured via a simple resistive voltage divider, which
determines changes in conductance of the skin. Changes in the signal (voltage) correspond to
changes in skin conductance, which might indicate changes in stress level, or indicate the
emotional state of a learner. An optical sensor was selected for HR, as it is non-invasive
to the learning process. Criteria for the choice of an acceleration sensor are low energy
consumption, small size and low costs. Wearability was not a design concern of the
actual prototype, further versions will be implemented as suitable wearable devices. For this
experiment, the focus was on the collection of sensor data, and the relationship between
sensor data and the learning domain.</p>
        <p>To explore the prototype in educational context, emotional intelligence questionnaires
(measuring affective domain in a learning context) were provided to the students.
During the experiments, EDA, HR and acceleration data were measured. Participants’ writing
hand (active hand) was wired with an accelerometer and their inactive hand was wired
with the EDA and the HR sensors. Even though the HR and the accelerometer provided
interesting data to review, the focus of this analysis was on the relationship between the
EDA and the affective learning domain (emotional intelligence), as the emotion in learning
poses an important indicator for self-regulation in motivation and metacognition, and it is
strongly linked to predict academic success [Pe02]. For the detection of the emotion, the
EDA sensor was chosen based on previous literature research [Ca13] [Mc12] [La93].</p>
        <p>Abb. 2: EDA signal of participant with highest emotional intelligence
Data from a total of 13 participants were collected for analysis. The mean response time for
each question was 8.6 seconds among all participants and the lowest emotional intelligence
observed was 61%, whereas the highest quotient was 88%. Due to the insufficient sample
size (N = 13), these results cannot be generalized, yet it was observable that for each
question, regardless of the response scale, the EDA signal shows a peak as shown in Abb.
2 and 3.</p>
        <p>Abb. 3: EDA signal of participant with lowest emotional intelligence
From the observation of the participants’ data, the participants with a higher emotional
intelligence show less fluctuation in the EDA signal between the beginning and the end of
the experiment (Abb. 2). However, this may be due to the cognitive effort of a participant
during the experiment [Bo92] [VV96]. Also, the emotional state of frustration [LN04],
unpleasantness [Se09] or undefined factors might have an affect. A further study with a
Sensor Data for Learning Support 33
sample size of N=50 and above should be followed to investigate the relationship between
the EDA data and the learning state.
3.2</p>
      </sec>
      <sec id="sec-3-2">
        <title>Applications for Sensor-Based Learning Analytics</title>
        <p>The potential of a sensor device like the prototype presented in 3.1 emerges when
analyzing possible applications in different teaching styles: blended learning courses in
universities, pure online courses, informal learning platforms and gamification applications. We
consider these teaching styles in industrial education contexts and university, addressing
students in secondary school and higher education as target groups.</p>
        <p>In May 2016 a focus group consisting of 12 participants (9 students, 2 scientific assistants,
1 professor) led by the HTW discussed their learning habits in detail, without
specifically discussing e-learning environments. The discussion revealed several support
interests: helping with the learning content, managing time, logging of learning activities,
evaluating development and performance, proposing of better learning techniques, reducing
distraction, providing real time feedback and health state.</p>
        <p>For the application in blended learning courses, students of Computer Science at
HumboldtUniversity were asked to explore the potential of a sensory aid by defining personas as
typical users and their usage scenarios. The task was assigned to them as two exercise
sessions of 1.5 hours each in summer 2016. Several needs result from the defined personas,
like optimization of their learning times and concentration phases, formative feedback,
and regular summative feedback, reduction of distractions, learning on the run, and
including handwriting and speech into the digital learning settings. The scenarios combined
explicit preference settings, data tracked by the online learning environment and
physiological sensor data. For example, one application focused on reducing distractions, defines
active phases and breaks, blocks apps and websites, unblocks them during breaks, and if
it recognizes a lack of concentration during an active phase, it intervenes with differently
presented content to catch the user’s attention again.</p>
        <p>A pure online learning application are e-learning courses for distance learning
universities. The missing personal contact enforces the need for automated assessment and
feedback, allowing the users to optimize their learning. Established learning management
systems like Canvas, Open edX or Moodle are providing visual dashboards helping with self
awareness [Ve13]. They base on performance monitoring within the system and interaction
tracked by the system or the respective plugins, but lack in analyzing parameters beyond
the system. Including data about the physical environment and physiological data of the
learners is an open research question. The difficulty here is to determine the proxy
variables for observation of the learning process - is it the pulse rate, room temperature, or the
combination of noise and eye-movements that makes a difference. An approach
addressing this issue could be a dashboard finding autonomously correlations between the sensed
data, tracked interaction data and the performance of the user. Adequate assessment like
these statements could be desirable, e.g. “Sustained and unchanging low level activity
lowers concentration.”, “A short rest, or a change in activity, every 15 minutes or so restores
performance almost to the original level.” [Bi03] Another ongoing research topic opens
the visualization form itself, presenting the data adequately for the user [Ve13].
Informal teaching like tutorials and news blogs, as often applied for internal training in
bigger companies or simply personal extension studies, might benefit from sensory data
for personalization and context awareness. To provide an example, we consider a sanitary
retail employee learning through an online training magazine about hygiene and a new
product. The magazine presents its contents to the user in a very personalized way, by
generating an adaptive learning path, fitting the user’s learning situation, knowledge and
emotions. This way the learning outcome could be enhanced, similar as sales volume of
online shops grows with personalized offers. Context awareness for the above situation
could allow training the installation of the new product in augmented or virtual reality
at home. In the retail situation, the magazine could offer context aware informations to
answer customers questions quickly.</p>
        <p>Gamification approaches for learning are bringing even more possibilities to use sensors,
supporting the fun factor and therefore addressing the affective learning domain more than
other learning forms. For example, secondary school children could learn about brain
functionality through a game challenging dexterity, speed and teamplay. Physiological sensors
can be used for intentional game control, but also for adapting to the feelings of the user,
adjusting the difficulty of the gameplay or complexity level of the learned content. In
serious games as applied by professionals in emergency for the training of dangerous
situations, even feelings themselves could be part of the learning content and adequate reaction
could be tought. One example: “Biohazard: Hot zone, is a game aimed to help emergency
first responders deal with toxic spills in public locations. In the game, users work in teams,
responding to a gas attack in a suburban shopping mall. The aim of the game is to help
people prepare for potentially catastrophic situations.” [SJB07].</p>
        <p>Some analogies appear between the applications. The needs identified by HTW Berlin
and Humboldt-University are similar, differences could be explained by the observation
methods and questions asked to the students. Common interests in blended and
informal online learning are personalized and adaptive learning paths to support motivation
and optimize the learning outcome. Correlating learning performance with mental states
like uncertainty, boredom, concentration or frustration and adequate adaptive reactions of
learning systems is a great chance for enhancing the learning experience, across multiple
teaching styles and subjects. The input of informations about the mental states is most
likely to be achieved utilizing personal sensor devices for learners.
3.3</p>
      </sec>
      <sec id="sec-3-3">
        <title>Privacy and Ethical Issues</title>
        <p>Learner-centric analysis of educational data retrieved from various learning environments
aims at improving learning, and at providing a better learning experience. Combining
activity data from a learning environment with physiological data obtained from wearable
sensors leads to rich data sets, with new chances for the adaption of the learning
environment and personalized learning support. On the other hand, analyzing a learner’s
physiological data poses a big challenge, and many open questions, to learning analytics: what
Sensor Data for Learning Support 35
are the ethical, legal and social applications of learning (analytics) applications, that might
process, store, analyze, or visualize personal data? Legal implications are obvious: any
learning application must be compliant with (national) data privacy legislation. An even
more critical issue is the acceptance of a learning support system by the learner: recording
and usage of sensor data must be completely transparent to the user, under the control of
the learner, and private data with no relevance to the learning process must not be analyzed!
Research on ELSI - ethical, legal, social implications of emerging life sciences - goes
back to bioethics, and to the Human Genome Project (HGP) [TBM97]. Beyond the HGP,
ELSI guidelines have been formulated for many projects and applications which collect,
process and share personal data, an example being ELSI guidelines for biomedical data at
the European Bioinformatics Institute.</p>
        <p>To meet the demands of an ELSI compliant learning application, a technical concept to
provide data privacy is essential. Data privacy is a central concept for learning analytics
[PS14] but recently, privacy has also been regarded as a limiting factor for the adaption of
learning analytics [DG16]. With advances in sensor technology, and with the availability
of sensor-based applications in everyday life, ethical and privacy issues have to resolved
[Bo04]. This not only applies to popular health or fitness apps, but also to learning
applications using sensor data.</p>
        <p>A learning analytics system, which uses a sensor device as presented in 3.1, needs a
technical data privacy concept on different layers: on the layer of the learning application /
learning environment, on the layer of a learning analytics engine (backend), providing
services for learner support, and on the layer of a sensor device.</p>
        <p>For the scenarios with a sensor device, a data privacy concept should address different
topcis: locality of sensor data, user interaction, a technical concept for exchange and
storage of learners’ data, a non-technical concept for learning scenarios and applications, and
transparency to a user.</p>
        <p>Locality of sensor data means that sensor data are filtered, processed and stored within
the smart monitor - only data relevant for learner support are transmitted to a learning
analytics application. Example: heart rate sensors provide very detailed information about
a learner’s health, whereas just a pulse rate might be needed as an indicator for the
actual learning state. The process of filtering data, and maintaining data locality, must be
transparent, and should be controlled by the learner himself. This implies the need for
local interaction with the SmartMonitor, as part of the interaction and usability concept.
Transparency also implies visualizing data (which are kept local) on a sensor device.
An emerging standard for the exchange and storage of educational data is the xAPI
(Experience API), which evolved from the TinCan project [KR16]. xAPI was designed for
better interoperability between different educational systems, which allows to link sensor
data to a system for self-regulated learning [MCL15]. xAPI “recipes”, which can help with
the design of xAPI systems can be found in [Ba15]. From a data privacy view, personal
data lockers can be implemented as an extension to learner record stores, defined in xAPI.</p>
        <p>Personal data lockers transfer control over personal learner data from an analytics system
to the user (learner), forming the basis of a technical data privacy concept.
Finally, a non-technical data privacy concept for the above mentioned learning applications
and scenarios addresses legal and ethical issues. This includes transparent definition,
configuration and enforcement of data ownership. Also, the results of data analyses, in form
of feedback, recommendation, or adaption of the learning environment, must be easy to
comprehend for learners. Both data privacy and transparency form the basis of a learning
application or tool which is acceptable by learners.
4</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>Conclusion</title>
      <p>In this paper, we addressed an area that the Learning Analytics research community is
currently starting to investigate: the use of data collected by various sensors in order to
provide effective learning support. While several studies on the applicability of specific
sensors as predictors for certain cognitive or affective states have been conducted, limited
research on the use of integrated data coming from multiple sensors available. Also, there
is a lack of research on how to provide learners with an overview of this multiple sensor
data and analysis results so that they can regulate their learning processes aided by this
information. Furthermore, design solutions that respect privacy while providing efficient
learning support need further investigations.</p>
      <p>The technical design solution (shown in early prototype stage) and the use case
scenarios presented in this paper will be further explored as part of a recently started research
project funded by the German Ministry of Education and Research. In this project, we are
currently eliciting requirements and designing use case scenarios for sensor based learning
analytics technologies by taking into account educational, content-related,
methodological, technical and ethical perspectives. Based on these, we will then design, implement
and evaluate learning analytics methods for supporting self-directed learning in
different sensor based environments. Three company partners will then implement and test the
methods in the different scenarios sketched in section 3 of this paper: while NEOCOSMO
will focus on professional education in the hygiene sector, SGM will investigate e-learning
applications for the higher education sector, and Promotion Software is going to develop
educational games. All of these scenarios (plus additional university application areas) will
serve as test beds for empirically validating the acceptance and efficiency of the Learning
Analytics methods and the technology used to implement them in both professional and
university settings.</p>
    </sec>
    <sec id="sec-5">
      <title>Acknowledgements</title>
      <p>This research was funded by the BMBF (German Ministry of Education and Research)
under the grant “LISA - Learning Analytics fu¨r sensorbasiertes adaptives Lernen”.
Sensor Data for Learning Support 37
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