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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>OntoMathEdu Educational Mathematical Ontology: Prerequisites, Educational Levels and Educational Projections</article-title>
      </title-group>
      <contrib-group>
        <aff id="aff0">
          <label>0</label>
          <institution>Joint Supercomputer Center of the Russian Academy of Sciences</institution>
          ,
          <addr-line>Kazan</addr-line>
          ,
          <country country="RU">Russia</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Kazan Federal University</institution>
          ,
          <addr-line>Kazan</addr-line>
          ,
          <country country="RU">Russia</country>
        </aff>
      </contrib-group>
      <fpage>0000</fpage>
      <lpage>0003</lpage>
      <abstract>
        <p>The work is dedicated to development of prerequisite relationships of the educational mathematical ontology OntoMathEdu. The concept A is called a prerequisite for the concept B, if a learner must study the concept A before approaching the concept B. OntoMathEdu provides two approaches for defining prerequisite relationships: directly by establishing a relationship between concepts and indirectly by arrangement the concepts by educational levels. Prerequisite relationships and educational projections will be used in developing of digital mathematical educational platform of Kazan Federal University.</p>
      </abstract>
      <kwd-group>
        <kwd>Prerequisite</kwd>
        <kwd>Ontology</kwd>
        <kwd>Mathematical education</kwd>
        <kwd>OntoMathEdu</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>
        This work is dedicated to development of prerequisite relationships of the educational
mathematical ontology OntoMathEdu [
        <xref ref-type="bibr" rid="ref1 ref2 ref3">1-3</xref>
        ].
      </p>
      <p>This ontology is intended to be a Linked Open Data hub for mathematical education,
a linguistic resource for intelligent mathematical language processing and an end-user
reference educational database. The ontology is organized in three layers: a
foundational ontology layer, a domain ontology layer and a linguistic layer. The domain
ontology layer contains language-independent math concepts from the secondary school
mathematics curriculum. The concepts are organized in two hierarchies: a hierarchy of
objects (such as Line segment, Triangle, Inscribed polygon, or Pythagorean Theorem)
and a hierarchy of reified relationships (such as Relationship between a tangent line
and a circle). The linguistic layer contains multilingual lexicons, providing linguistic
grounding for the concepts from the domain ontology layer. The foundation ontology
layer provides the concepts with meta-ontological annotations. The current version of
OntoMathEdu contains 896 concepts from the secondary school Euclidean plane
geometry curriculum.</p>
      <p>
        OntoMathEdu is a component of OntoMath digital ecosystem [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ], an ecosystem of
ontologies, text analytics tools, and applications for mathematical knowledge
management, including semantic search for mathematical formulas [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ] and a recommender
system for mathematical papers [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. OntoMath, in turn, underlines the Lobachevskii-DML
digital mathematical library (https://lobachevskii-dml.ru/) [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] and a digital educational
mathematical platform of Kazan Federal University under development.
      </p>
      <p>For the ontology can be used for educational purposes, the logical relations between
concepts must be complemented with the prerequisite ones. The concept A is called a
prerequisite for the concept B, if a learner must study the concept A before approaching
the concept B. For example, comprehension of the Addition concept is required to grasp
the concept of Multiplication, and, more interesting, to grasp the very concept of
Function, even though, from the logical point of view the later concept is more fundamental
and is used in the definitions of the first two.</p>
      <p>
        Prerequisite relationships are used in such tasks as automatic reading list generation
[
        <xref ref-type="bibr" rid="ref8">8</xref>
        ], curriculum planning [
        <xref ref-type="bibr" rid="ref10 ref9">9, 10</xref>
        ], evaluation of educational resources [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ] and
prediction of academic performance [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ].
2
      </p>
    </sec>
    <sec id="sec-2">
      <title>Prerequisites, Educational Levels and Educational Projections</title>
      <p>In contrast to logical relationships between concepts, prerequisite relationships are not
universal and are relativized to particular education systems: given two concepts A and
B, the prerequisite relation can hold between them in one education system, but doesn’t
hold in another. In particular, for the concept A that is prerequisite of the concept B in
one education system, the following options are possible with respect to another
education system:
─ A is a prerequisite of B too. For example, Circle is a prerequisite of Circumference
in both the Russian and the UK education systems.
─ A is a prerequisite of C, and C is a prerequisite of B. For example, in UK education
system, Angle is a prerequisite of Alternate interior angles, while in Russian
education system, Angle is a prerequisite of Alternate angles and Alternate angles is
prerequisite of Alternate interior angles.
─ B is a prerequisite of A. There aren’t examples of this pattern in the current version
of OntoMathEdu, but such pair of concepts can be Set and Function, or Circle and
Disk.
─ A isn’t a prerequisite of B, because A and B are learned independently. For example,
in the UK education system, Plane motion is a prerequisite of Area of a polygon,
while in the Russian education system it isn’t, because Plane motion and Area of a
polygon are independent.
─ A isn’t a prerequisite of B, because A or B are not studied at all. For example, the
prerequisite relation holds between Angle and Complementary angles concepts in
the UK education system, but doesn’t hold in the Russian education system, because
the Complementary angles concept is not studied in it.</p>
      <p>OntoMathEdu provides two approaches for defining prerequisite relationships: a
direct and an indirect ones.</p>
      <p>Direct approach. According to the direct approach, a prerequisite relationship is
established directly between two concepts.</p>
      <p>
        In order to relativize the relation to an education system, we intend using of
“Descriptions and Situations” (D&amp;S) design pattern, based on the top-level ontology
DOLCE + DnS Ultralite [
        <xref ref-type="bibr" rid="ref13 ref14 ref15">13-15</xref>
        ]. However, manual annotation of D&amp;S’s is
labourintensive task.
      </p>
      <p>As an alternative, the concepts can be linked by a subpropertis of the has prerequisite
object property, corresponding to education systems, namely: has prerequisite
according to the Russian education system, has prerequisite according to the UK education
system and other.</p>
      <p>Indirect approach. According to indirect approach, prerequisite relationships are
established by arrangement of the concepts by educational levels.</p>
      <p>Educational levels are the successive segments of the curriculum of an education
system and roughly correspond to education grades. In the UK education system, the
education levels are: Key stage 1 (1st–2nd years of study), Key stage 2 (3rd–6th years
of study), Key stage 3 (7th–9th years of study), Kеy stage 4 (10th–11th years of study).
In the Russian education system, the education levels are: 7 grade, 8 grade, 8 grade
(extended), 9 grade, 9 grade (extended), and Additional program.
Every concept can belong to one education level of a given education system.</p>
      <p>Just like concepts, educational levels are also related by prerequisite relation. The
level L1 is called a prerequisite for the level L2, if a learner must study the content of
the level L1 before approaching the content of the level L2. In terms of the direct
prerequisite relationships between concepts, a prerequisite relationship between two levels
can be interpreted as follows: if the level L1 is called a prerequisite for the level L2,
then for every concept, belonging to L2 there is a prerequisite concept, belonging to L1.</p>
      <p>Educational projections. Arrangement of concepts to educational levels allows to
extract a projection of ontology to an education system (educational projection). An
educational projection of the OntoMathEdu ontology to education system S is a fragment
of the ontology, containing all the concepts, that belong to educational levels of this
education system. For example, the Russian education projection of OntoMathEdu
consists in the concepts, belonging to grade 7, grade 8, grade 8 (extended), etc.
3</p>
    </sec>
    <sec id="sec-3">
      <title>Conclusion</title>
      <p>In this paper, we describe two approaches for defining prerequisite relationships:
directly by establishing a relationship between concepts and indirectly by arrangement
the concepts by educational levels. Arrangement of concepts by educational levels, in
turn, allows to extract a projection of ontology to an education system (educational
projection). Prerequisite relationships and educational projections will be used in
developing of digital mathematical educational platform of Kazan Federal University.</p>
      <p>This work was funded by RFBR, projects #19-29-14084 and #18-47-160007.
Contribution of A. Kirillovich was partially funded by the state assignment to the Federal
State Institution “Scientific Research Institute for System Analysis of the Russian
Academy of Sciences” for scientific research</p>
    </sec>
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