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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>The impact of feedback on students' a ective states</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Beate Grawemeyer</string-name>
          <email>beate@dcs.bbk.ac.uk</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Manolis Mavrikis</string-name>
          <email>m.mavrikis@ioe.ac.uk</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Wayne Holmes</string-name>
          <email>w.holmes@ioe.ac.uk</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Alice Hansen</string-name>
          <email>a.hansen@ioe.ac.uk</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Katharina Loibl</string-name>
          <email>katharina.loibl@rub.de</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sergio Gutierrez-Santos</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Institute of Educational Research, Ruhr-Universitat Bochum</institution>
          ,
          <country country="DE">Germany</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>London Knowledge Lab, Dep of Computer Science and Information Systems</institution>
          ,
          <addr-line>Birkbeck, London</addr-line>
          ,
          <country country="UK">UK</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>London Knowledge Lab, UCL Institute of Education, University College London</institution>
          ,
          <addr-line>London</addr-line>
          ,
          <country country="UK">UK</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>A ective states play a signi cant role in students' learning behaviour. Positive a ective states can enhance learning, while negative a ective states can inhibit it. This paper describes a Wizard-of-Oz study that investigates the impact of di erent types of feedback on students' a ective states. Our results indicate the importance of providing feedback matched carefully to the a ective state of the students in order to help them transition into more positive states. For example when students were confused a ect boosts and speci c instructive feedback seem to be e ective in helping students to be in ow again. We discuss this and other ways to adapt the feedback, together with implications for the development of our system and the eld in general.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>This paper reports the results of a set of two Wizard-of-Oz studies which explore
the e ect of di erent feedback types on students' a ective states.</p>
      <p>
        It is well understood by now that a ect interacts with and in uences the
learning process [
        <xref ref-type="bibr" rid="ref2 ref6 ref9">9, 6, 2</xref>
        ]. While positive a ective states such as surprise,
satisfaction or curiosity contribute towards constructive learning, negative ones
including frustration or disillusionment at realising misconceptions can lead to
challenges in learning. The learning process is indeed full of transitions between
positive and negative a ective states and regulating those is important. For
example, a student may seem interested in exploring a particular learning goal,
however s/he might have some misconceptions and need to reconsider her/his
knowledge. This can evoke frustration and/or disappointment. However, this
negative a ective state may turn into deep engagement with the task again.
D'Mello et al., for example, elaborate on how confusion is likely to promote
learning under appropriate conditions [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>
        It is important therefore, to deepen our understanding of the role of a ective
states for learning, and to be able to move students out of states that inhibit
learning. Pekrun [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ] discusses achievement emotions or a ective states, which
arise in a learning situation. Achievement emotions are states that are linked to
learning, instruction, and achievement. We focus on a subset of a ective states
identi ed by Pekrun: ow/enjoyment, surprise, frustration, and boredom. We
also add confusion, which has been identi ed elsewhere as an important a ective
state during learning [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ] for tutor support and for learning in general [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>
        As described in Woolf et al. [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ] students can become overwhelmed (very
confused or frustrated) during learning, which may increase cognitive load [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ]
for low-ability or novice students. However, appropriate feedback might help to
overcome such problems. Carenini et al. [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ] describe how e ective support or
feedback needs to answer three main questions: (i) when the support should be
provided during learning; (ii) what the support should contain; and (iii) how it
should be presented.
      </p>
      <p>In this paper we focus on the question of what the support should contain
with respect to a ect i.e. the types of feedback that are able to induce a positive
a ective state.</p>
      <p>
        In related work students' a ective states have been used to tailor motivational
feedback and learning material in order to enhance the learning experience.
For example, Santos et al. [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ] show that a ect as well as motivation and
selfe cacy impact the e ectiveness of motivational feedback and recommendations.
Additionally, Woolf et al. [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ] developed an a ective pedagogical agent which is
able to mirror a student's a ective state, or acknowledge a student's a ective
state if it is negative. Another example is Conati &amp; MacLaren [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], who developed
a pedagogical agent to provide support according to the a ective state of the
students and the user's personal goal. Also, Shen et al. [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ] recommend learning
material to the student based on their a ective state. D'Mello et al. [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] developed
a system that is able to respond to students via a conversation that takes into
account the a ective state of the student.
      </p>
      <p>In contrast, in this paper, we investigate the impact of di erent types of
feedback on students' a ective state and how and whether they can help students
regulate their a ect and thus improve learning. In what follows we present two
sets of Wizard-of-Oz studies where feedback was provided to students interacting
with an exploratory learning environment designed to learn fractions. From these
studies, the a ective states of the students were carefully annotated in order to
address our research questions.
2
2.1</p>
    </sec>
    <sec id="sec-2">
      <title>The Wizard-of-Oz studies</title>
      <sec id="sec-2-1">
        <title>Aims</title>
        <p>One of our research aims is to develop intelligent support that enhances the
learning experience by taking into account the student's a ective state. We were
speci cally interested in identifying how di erent feedback types modify a ective
states.</p>
        <p>
          In order to address this question we conducted two sets of ecologically valid
Wizard-of-Oz studies (e.g. [
          <xref ref-type="bibr" rid="ref11 ref8">11, 8</xref>
          ]) which investigated the e ect of a ective states
on di erent feedback types at di erent stages of the task.
2.2
        </p>
      </sec>
      <sec id="sec-2-2">
        <title>Participants and Procedure</title>
        <p>In total, 26 Year-5 (9 to 10-year old) students took part in the Wizard-of-Oz
studies. Each session lasted on average 20 minutes. Each student participated in
one Wizard-of-Oz session.</p>
        <p>
          The sessions were run in an ordinary classroom with multiple computers,
where additional children were working with the learning platform (not
wizarded) in order to support ecological validity. This was important particularly
as in early settings we identi ed that children would not speak that much to the
platform if they felt that they were monitored [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ]. Figure 1 shows the setup of
the studies. Wizards followed a script with pre-canned messages to send
messages to the students through the learning platform and deliberately limited
their communication capacity in order to simulate the actual system. To achieve
that wizards were only able to see students' screen. An assistant was able to
hear students' reactions to re ections or talk-aloud prompts (as prompted by
the `system') and provide recommendations to the wizard with respect to the
detected a ective state. Any feedback provided was both shown on screen and
read aloud by the system to students.
2.3
        </p>
      </sec>
      <sec id="sec-2-3">
        <title>Feedback types</title>
        <p>Di erent types of feedback were presented to students at di erent stages of their
learning task. The feedback provided was based on interaction via keyboard and
mouse, as well as speech.</p>
        <p>
          We explore di erent types of feedback that are known from the literature to
support students in their learning and t our context. The following di erent
feedback types were provided:
{ AFFECT BOOSTS - a ect boosts. As described in [
          <xref ref-type="bibr" rid="ref20">20</xref>
          ] a ect boosts
can help to enhance student's motivation in solving a particular learning
task. These included prompts that acknowledged for example that a task is
di cult or that the student may be confused but they should keep trying.
{ INSTRUCTIVE FEEDBACK - instructive task-dependent
feedback. This feedback provided detailed instructions, what subtask or action
to perform in order to solve the task.
{ OTHER PROBLEM SOLVING FEEDBACK - task-dependent
feedback. This support was centred on helping students to solve a particular
problem that they are facing during their interaction by providing either
questions to challenge their thinking or speci c hints designed to help them
identify the next step themselves.
{ TALK ALOUD PROMPTS - talking aloud. With respect to learning
in particular, the hypothesis that automatic speech recognition (ASR) can
facilitate learning is based mostly on educational research that has shown
bene ts of verbalization for learning (e.g., [
          <xref ref-type="bibr" rid="ref1">1</xref>
          ]).
{ REFLECTIVE PROMPTS - re ecting on task performance and
learning. Self-explanation can be viewed as a tool to address students' own
misunderstandings [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ] and as a `window' into students' thinking.
{ TALK MATHEMATICS PROMPTS - using particular domain
speci c mathematics vocabulary. The aim of this prompt was to
encourage students to use mathematical vocabulary in order continually revise
their interpretations. In early studies [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ] we found that students' re ections
were often procedural and pragmatic (e.g. talking about the user interface)
rather than mathematical.
{ TASK SEQUENCE PROMPTS - moving to the next task. This
feedback is centred on providing support regarding what action to perform
next in order to change the task, such as clicking the `Next' button.
        </p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Annotation of a ective states and feedback reactions</title>
      <p>From the Wizard-of-Oz studies we recorded the students' screen display and their
voices. From this data, we annotated a ective states (e.g. screen interaction and
what the students said) before and after feedback was provided.</p>
      <p>
        As described earlier, for the a ective state detection we discriminated
between ve di erent a ective types: enjoyment, surprise, confusion, frustration,
and boredom. For the annotation of those a ective states we used a similar
strategy to that described in [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ], where a dialogue between a teacher and a student
was annotated retrospectively by categorising utterances in terms of di erent
feedback types. Also, [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ] describe how they coded di erent a ective states based
on observations of students interacting with a learning environment. Similarly,
we annotated student's a ective states for each type of feedback provided. In
addition to the student's voice we also used the video of the screen capture
to support the annotation process. Students' a ective states were annotated as
follows:
{ FLOW: Engagement with the learning task. Statements like `I am enjoying
this task' or `This is fun'. Sustained interaction with the system.
Feedback type Example
AFFECT BOOSTS You're working really hard! Keep
going!
INSTRUCTIVE FEEDBACK Use the comparison box to compare
your fractions.
      </p>
      <p>OTHER PROBLEM SOLVING FEEDBACK If you add fractions, they need to
have the same denominators rst.</p>
      <p>REFLECTIVE PROMPTS What do you notice about the two
fractions?
TALK ALOUD PROMPTS Remember to talk aloud, what are
you thinking?
TALK MATHEMATICS PROMPTS Can you explain that again using
the terms denominator, numerator?
TASK SEQUENCE PROMPTS Well done. When you are ready click
`next' for the next task.
{ SURPRISE: Gasping. Statements like `Huh?' or `Oh, no!'.
{ CONFUSION: Failing to perform a particular task. Statements such as
`I'm confused!' or `Why didn't it work?'. Uncertain interaction with the
system.
{ FRUSTRATION: Tendency to give up, repeatedly clicking or deleting
of objects in the system or repeatedly failing to perform a particular task,
sighing, statements such as, `What's going on?!'.
{ BOREDOM: Inactivity or statements such as `Can we do something else?'
or `This is boring'.
4</p>
    </sec>
    <sec id="sec-4">
      <title>Results</title>
      <p>In total 396 messages were sent to 26 students. The video data in combination
with the sound les were analysed independently by three researchers (one was
independent of the project) who categorised the a ective states of students before
and after the feedback messages were provided.</p>
      <p>
        The data is combined from two sets of Wizard-of-Oz studies. We use kappa
statistics to measure the degree of the agreements of the annotations for
reliability. Kappa was .46, p&lt;.001. This is generally expected from retrospective
annotation of naturalistic a ect experiences [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ]. We consolidated the
annotations based on discussion between the annotators and the rest of the authors of
the paper in order to agree upon the annotations that did not match originally.
In the second set we had resources to introduce the Baker-Rodrigo
Observation Method Protocol (BROMP) and the HART mobile app that facilitates the
coding of students a ective states in the classroom [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. Kappa based on the
retrospective annotation was still .56, p&lt;.001. We rst consolidated the data
with the same approach as before and then compared against the eld
annotations. Kappa between the consolidated annotation and the HART data was .71,
p&lt;.05 (note that is may appear low but we did not expect the retrospective
annotation to get surprise and frustration accurately). We used the HART data to
improve the annotation by mapping feedback actions against the observation for
20 seconds prior to the delivery of the feedback to 20 seconds after the student
had closed the corresponding feedback window. We marked the changes for an
independent annotator to revisit the rst set of annotations.
      </p>
      <p>The student's a ective states, that occurred before and after the di erent
types of feedback was provided, can be seen in gure 2. Each block shows an
a ective state before feedback was provided. The colour within the bars indicates
the type of a ective states that occurred after the feedback was provided. The
number within the bars indicate the number of times the a ective state occurred.</p>
      <p>
        In order to investigate whether there was an e ect of the feedback on the
learning experience, we looked at whether a student's a ective state was
enhanced, stayed the same or worsened. An a ective state was enhanced for
example, when it was changed from confusion to ow, or (given the ndings about
confusion [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]) from frustration to confusion, frustration to ow, boredom to ow
etc. An a ective state was worsened if it moved for example, from ow to
frustration or confusion, or from confusion to frustration.
      </p>
      <p>
        As the data is categorical [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ], we apply chi-square tests to investigate
statistical signi cant di erences between the groups. We present them below and
discuss in more detail in the next section.
      </p>
      <p>Flow When students were in ow, there was no signi cant di erence between
the feedback types on whether the a ective state stayed in the same ow state
(X2(6, N=169) = 4.31, p&gt;.05) or worsened (X2(6, N=169) = 4.89, p&gt;.05). As
ow is the most positive a ective state, the a ective state in this sub-sample
cannot be enhanced.</p>
      <p>Confusion When students were confused, there was a signi cant e ect of the
feedback type on whether students' a ective state was enhanced into a ow state
(X2(6, N=181) = 13.65, p&lt;.05). The most e ective feedback types were a ect
boosts with 68% of the cases, followed by guidance feedback with 67%, and task
sequence prompts with 63%. Re ective prompts resulted in a ow state in 48%
of the cases, talk aloud prompts 38%, and problem solving support with 34%.
Talk maths prompts were the least e ective with only 25% of the cases.</p>
      <p>There was also a signi cant e ect of the feedback type and whether the
a ective state stayed the same (X2(6, N=181) = 14.34, p&lt;.05). Talk maths
prompts were highest associated with a continuing confused state with 75% of
the cases. This was followed by problem solving support with 66%, talk aloud
prompts with 59%, re ective prompts with 52%, task sequence prompts with
37%, a ect boosts with 32%, and the least feedback type that was associated
with a continuing confused state were guidance feedback with 29% of the cases.</p>
      <p>There was no signi cant association between the feedback type and whether
the a ective state worsened (X2(6, N=181) = 4.65, p&gt;.05).
Frustration, boredom and surprise There was not su cient data available
when students were frustrated (36 cases), nor when they were bored (9 cases),
or surprised (3 cases) to run a statistical test across the di erent a ective states
and feedback types.</p>
      <p>However, the data indicates that some of the provided feedback types were
better able to change the a ective state of the student when they were frustrated,
bored or surprised, as can be seen in gure 2. For example, 60% of the a ect
boosts were able to change frustration into ow, followed by re ective prompts
33% and problem solving support 20%.
5</p>
    </sec>
    <sec id="sec-5">
      <title>Discussion</title>
      <p>The results presented in the previous section show that feedback can enhance
students' a ective states, and that the impact of the various feedback types
mostly depends on the students' a ective state before the feedback was provided.</p>
      <p>When students were in ow there was no signi cant di erence between the
feedback types on whether or not the a ective state stayed the same or
worsened. This suggests that, when students are in ow, challenging feedback can be
provided without negative implications.</p>
      <p>However, when students were confused there was a di erence between the
feedback types on whether the a ective state was enhanced, stayed the same
or worsened. The feedback types that most e ectively moved the student out
of a confusion state were a ect boosts, instructive, and task sequence prompts.
When they were struggling to overcome problems, a ect boosts appeared to
encourage some students to redouble their e orts without the need for task
speci c support. We can hypothesise that this enabled students to self-regulate
their a ect and move forward. As expected, instructive feedback appears to
have given the students the next steps that they needed, whereas other problem
solving was less successful. Other problem solving feedback seems to have led
students to be more confused because of the increased cognitive load caused by
them having to understand the hint or the question provided.</p>
      <p>While talk aloud prompts and talk maths, encouraged them to vocalize what
they are trying to achieve, they appear not to have helped the students address
their confusions. Instead, when they were confused, students appeared to have
welcomed a new task (the opportunity to abandon the cause of their confusion).
While as a strategy this can be pedagogically debatable, there is scope to
provide tasks aimed to help them at the same concepts in a di erent, simpler way
or to allow them to practice rst some skills in a practice-based rather than
exploratory task.</p>
      <p>Although there was insu cient data to analyse the impact of the di erent
feedback types on students' a ective state when they were frustrated, some
tentative observations can be made. For example, it was evident that the a ect of
students who were frustrated was enhanced whatever the feedback they were
provided with. However, it is notable that the frustrated students who were
provided a ect boosts were most likely to move to a ow. We have other anecdotal
evidence in the same scenario with di erent students that suggest that explicitly
addressing a ect and helping students to think of their emotions during learning
can help them move to confused or to ow state without need for immediate
problem solving support.</p>
      <p>It is worth noting that compared to other research we may have been unable
to detect more negative states, especially boredom, because of the nature of the
environment that the students were using { an exploratory learning environment
that encouraged them to speak. The combination of unstructured learning and
speech might prevent students from becoming bored.
6</p>
    </sec>
    <sec id="sec-6">
      <title>Conclusion and future work</title>
      <p>The a ective state of students can be modi ed with feedback. There is a di
erence in the impact of di erent feedback types according to the a ective state
the student is in before the feedback was provided. Although there seems not
to be too much of a di erence when students are in ow, when students were
confused di erent feedback types seem to matter more. While, for example,
affect boosts and instructive feedback were able to change confusion into ow,
prompting students to use mathematical vocabulary or providing other problem
solving support, were associated with the same confused state or even lead to
frustration.</p>
      <p>
        In the light of ndings like D'Mello et al. [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] for example of the importance of
confusion under appropriate conditions in learning, our ndings have important
implications for learning and teaching in general, and AIED in particular.
Problem solving support speci cally in exploratory learning environments is di cult
to achieve successfully, particularly when students are in a situation that was not
previously encountered during a system's design. However, detecting a ect may
be relatively easier in certain contexts particularly in speech-enabled software
like in our case and therefore a ective support matters as much, if not more
than, problem solving support. In addition, the exact type of support provided
when students are frustrated is important. To understand this better we need to
investigate more the di erent types of problem solving support and their
combination with a ective feedback that can act both as a way to self-regulate a ect
and take student into a more positive state like confusion or ow.
      </p>
      <p>In our current study we are implying that learning performance is enhanced
when students are in a positive a ective state. In the future we are planning to
evaluate if learning performance will be enhanced when students are moved out
of a negative into a positive a ective state. Our next step is to train an intelligent
system that is able to tailor the type of feedback according to the a ective state
of the student in order to enhance the learning experience.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          1.
          <string-name>
            <surname>Askeland</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          :
          <article-title>Sound-based strategy training in multiplication</article-title>
          .
          <source>European Journal of Special Needs Education</source>
          <volume>27</volume>
          (
          <issue>2</issue>
          ),
          <volume>201</volume>
          {
          <fpage>217</fpage>
          (
          <year>2012</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          2.
          <string-name>
            <surname>Baker</surname>
            ,
            <given-names>R.S.J.d.</given-names>
          </string-name>
          , DMello,
          <string-name>
            <given-names>S.K.</given-names>
            ,
            <surname>Rodrigo</surname>
          </string-name>
          ,
          <string-name>
            <given-names>M.T.</given-names>
            ,
            <surname>Graesser</surname>
          </string-name>
          ,
          <string-name>
            <surname>A.C.</surname>
          </string-name>
          :
          <article-title>Better to be frustrated than bored: The incidence, persistence, and impact of learners cognitivea ective states during interactions with three di erent computer-based learning environments</article-title>
          .
          <source>Int. J. Hum.-Comput. Stud</source>
          .
          <volume>68</volume>
          (
          <issue>4</issue>
          ),
          <volume>223</volume>
          {
          <fpage>241</fpage>
          (
          <year>2010</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          3.
          <string-name>
            <surname>Carenini</surname>
            ,
            <given-names>G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Conati</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Hoque</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Steichen</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Toker</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Enns</surname>
          </string-name>
          , J.:
          <article-title>Highlighting interventions and user di erences: Informing adaptive information visualization support</article-title>
          .
          <source>In: Proceedings of CHI 14</source>
          . pp.
          <year>1835</year>
          {
          <year>1844</year>
          (
          <year>2014</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          4.
          <string-name>
            <surname>Chi</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          :
          <article-title>Self-explaining expository texts: The dual processes of generating inferences and repairing mental models</article-title>
          . In: Glaser,
          <string-name>
            <surname>R</surname>
          </string-name>
          . (ed.)
          <source>Advances in instructional psychology</source>
          , pp.
          <volume>161</volume>
          {
          <fpage>238</fpage>
          .
          <string-name>
            <surname>Mahwah</surname>
          </string-name>
          , NJ: Lawrence Erbaum Associates (
          <year>2000</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          5.
          <string-name>
            <surname>Conati</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>MacLaren</surname>
          </string-name>
          , H.:
          <article-title>Empirically building and evaluating a probabilistic model of user a ect. User Modeling</article-title>
          and
          <string-name>
            <surname>User-Adapted Interaction</surname>
          </string-name>
          (
          <year>2009</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          6.
          <string-name>
            <surname>DMello</surname>
            ,
            <given-names>S.K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Lehman</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Pekrun</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Graesser</surname>
            ,
            <given-names>A.C.</given-names>
          </string-name>
          :
          <article-title>Confusion can be bene cial for learning</article-title>
          .
          <source>Learning &amp; Instruction</source>
          <volume>29</volume>
          (
          <issue>1</issue>
          ),
          <volume>153</volume>
          {
          <fpage>170</fpage>
          (
          <year>2014</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          7.
          <string-name>
            <surname>DMello</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Craig</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Gholson</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Franklin</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Picard</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Graesser</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          :
          <article-title>Integrating a ect sensors in an intelligent tutoring system</article-title>
          .
          <source>In: A ective Interactions: The Computer in the A ective Loop Workshop at IUI 2005</source>
          . pp.
          <volume>7</volume>
          {
          <issue>13</issue>
          (
          <year>2005</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          8.
          <string-name>
            <surname>Eynon</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Davies</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Holmes</surname>
            ,
            <given-names>W.</given-names>
          </string-name>
          :
          <article-title>Supporting older adults in using technology for lifelong learning: the methodological and conceptual value of wizard of oz simulations</article-title>
          .
          <source>In: Proceedings of NLC 2012</source>
          . pp.
          <volume>66</volume>
          {
          <issue>73</issue>
          (
          <year>2012</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          9.
          <string-name>
            <surname>Kort</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Reilly</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Picard</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          :
          <article-title>An a ective model of the interplay between emotions and learning</article-title>
          .
          <source>In: Proceedings of ICALT 2001</source>
          . No.
          <volume>43</volume>
          {
          <issue>46</issue>
          (
          <year>2001</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          10.
          <string-name>
            <surname>Mavrikis</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Grawemeyer</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Hansen</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Gutierrez-Santos</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          :
          <article-title>Exploring the potential of speech recognition to support problem solving and re ection</article-title>
          .
          <source>In: ECTEL 2014</source>
          . pp.
          <volume>263</volume>
          {
          <issue>276</issue>
          (
          <year>2014</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          11.
          <string-name>
            <surname>Mavrikis</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Gutierrez-Santos</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          :
          <article-title>Not all wizards are from Oz: Iterative design of intelligent learning environments by communication capacity tapering</article-title>
          .
          <source>Computers &amp; Education</source>
          <volume>54</volume>
          (
          <issue>3</issue>
          ),
          <volume>641</volume>
          {
          <fpage>651</fpage>
          (
          <year>2010</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          12.
          <string-name>
            <surname>Ocumpaugh</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Baker</surname>
            ,
            <given-names>R.S.J.d.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Rodrigo</surname>
          </string-name>
          , M.M.T.:
          <article-title>Baker-Rodrigo Observation Method Protocol (BROMP) 1.0</article-title>
          .
          <source>Training Manual version 1.0. Tech. rep.</source>
          , New York, NY: EdLab. Manila, Philippines:
          <article-title>Ateneo Laboratory for the Learning Sciences</article-title>
          . (
          <year>2012</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          13.
          <string-name>
            <surname>Pekrun</surname>
            ,
            <given-names>R.:</given-names>
          </string-name>
          <article-title>The control-value theory of achievement emotions: Assumptions, corollaries, and implications for educational research and practice</article-title>
          .
          <source>J. Edu. Psych. Rev</source>
          . pp.
          <volume>315</volume>
          {
          <issue>341</issue>
          (
          <year>2006</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          14.
          <string-name>
            <surname>Porayska-Pomsta</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Mavrikis</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>DMello</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Conati</surname>
            ,
            <given-names>C.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>de</surname>
            <given-names>Baker</given-names>
          </string-name>
          , R.S.J.:
          <article-title>Knowledge elicitation methods for a ect modelling in education</article-title>
          .
          <source>I. J. Arti cial Intelligence in Education</source>
          <volume>22</volume>
          (
          <issue>3</issue>
          ),
          <volume>107</volume>
          {
          <fpage>140</fpage>
          (
          <year>2013</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          15.
          <string-name>
            <surname>Porayska-Pomsta</surname>
            ,
            <given-names>K.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Mavrikis</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Pain</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          :
          <article-title>Diagnosing and acting on student a ect: the tutors perspective</article-title>
          .
          <source>UMUAI</source>
          <volume>18</volume>
          (
          <issue>1</issue>
          ),
          <fpage>125</fpage>
          -
          <lpage>173</lpage>
          (
          <year>2008</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          16.
          <string-name>
            <surname>Rosenthal</surname>
            ,
            <given-names>R.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Rosnow</surname>
          </string-name>
          , R.: Essentials of Behavioral Research:
          <article-title>Methods and data analysis</article-title>
          .
          <source>McGraw Hill</source>
          ,
          <volume>3rd</volume>
          <fpage>edn</fpage>
          . (
          <year>2008</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          17.
          <string-name>
            <surname>Santos</surname>
            ,
            <given-names>O.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Saneiro</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Salmeron-Majadas</surname>
            ,
            <given-names>S.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>J.G.</surname>
          </string-name>
          ,
          <string-name>
            <surname>B.</surname>
          </string-name>
          :
          <article-title>A methodological approach to elicit a ective educational recommendataions</article-title>
          .
          <source>In: Proceedings of ICALT</source>
          <year>2014</year>
          (
          <year>2014</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          18.
          <string-name>
            <surname>Shen</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Wang</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Shen</surname>
            ,
            <given-names>R.:</given-names>
          </string-name>
          <article-title>A ective e-learning: Using emotional data to improve learning in pervasive learning environment</article-title>
          .
          <source>Educational Technology &amp; Society</source>
          <volume>12</volume>
          (
          <issue>2</issue>
          ),
          <volume>176</volume>
          {
          <fpage>189</fpage>
          (
          <year>2009</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          19.
          <string-name>
            <surname>Sweller</surname>
            , J., van Merrienboer,
            <given-names>J.G.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Paas</surname>
            ,
            <given-names>G.W.</given-names>
          </string-name>
          :
          <article-title>Cognitive Architecture and Instructional Design</article-title>
          .
          <source>Educational Psychology Review</source>
          <volume>10</volume>
          ,
          <issue>251</issue>
          {
          <fpage>296</fpage>
          + (
          <year>1998</year>
          )
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          20.
          <string-name>
            <surname>Woolf</surname>
            ,
            <given-names>B.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Burleson</surname>
            ,
            <given-names>W.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Arroyo</surname>
            ,
            <given-names>I.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Dragon</surname>
            ,
            <given-names>T.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Cooper</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Picard</surname>
            ,
            <given-names>R.:</given-names>
          </string-name>
          <article-title>A ectaware tutors: recognising and responding to student a ect</article-title>
          .
          <source>Int. J. Learning Technology</source>
          <volume>4</volume>
          (
          <issue>3-4</issue>
          ),
          <volume>129</volume>
          {
          <fpage>164</fpage>
          (
          <year>2009</year>
          )
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>