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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Towards a textbook on ontology-guided conceptual modeling</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Henderik A. Proper</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Bas van Gils</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Antwerp Management School</institution>
          ,
          <addr-line>Antwerp</addr-line>
          ,
          <country country="BE">Belgium</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Business Informatics Group, TU Wien</institution>
          ,
          <addr-line>Vienna</addr-line>
          ,
          <country country="AT">Austria</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Strategy Alliance</institution>
          ,
          <addr-line>Amersfoort</addr-line>
          ,
          <country country="NL">The Netherlands</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>This paper provides the outline of a planned textbook on conceptual modeling. The target audience of the planned textbook are learners of conceptual modeling in general, and bachelor-level students in particular. Our goal with this paper is to seek feedback regarding the setup of the planned textbook, as well as further validate the need for such a textbook. Next to discussing the planned content, and the underlying line of reasoning, of said textbook we will address both the motivation for its development, as well as some of our fundamental underlying assumptions.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Textbook</kwd>
        <kwd>Conceptual Modeling</kwd>
        <kwd>Ontology-Guided Modeling</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>
        The authors of this paper (and proposed textbook) have been involved in a broad range of
modeling related teaching engagements for diferent groups of learners. This ranges from
full-time bachelor and master students to practitioners. It also involved students with diverse
professional backgrounds across diferent programmes (e.g. business administration, information
management, or computer science). Content-wise, the teaching engagements pertained to e.g.
ArchiMate [
        <xref ref-type="bibr" rid="ref1 ref2">1, 2</xref>
        ], BPMN [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], DEMO [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ], and e3Value [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ], as well as fact-based modeling [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ].
      </p>
      <p>
        Across these teaching engagements, we see an underlying need to learn how to model, which
we consider to be a skill in itself, independent of the modeling language/framework that is
used. In line with this, and after checking the available books/literature, we think there is a
need for a textbook on learning conceptual modeling in general. The phrase “in general” in the
latter sentence, refers to the fact that we specifically consider conceptual modeling as having
a broader role to play [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] than a database-design-only one (as we often find it being ‘framed’
into). The primary target audience of the planned textbook are initial learners of conceptual
modeling, and bachelor-level students in particular. At the same time, we also keep in the back
of our minds that professionals may also need to (re)learn this important skill.
      </p>
      <p>
        In line with [
        <xref ref-type="bibr" rid="ref8 ref9">8, 9</xref>
        ], we suggest to start by teaching students to create conceptual models
that capture the (core) concepts and relationships in a domain, and to then teach them to
specialize such models towards more purpose/domain specific modeling languages. Some of
our own research also indicates that grounding e.g. UML models [
        <xref ref-type="bibr" rid="ref10 ref11">10, 11</xref>
        ], System Dynamics
models [
        <xref ref-type="bibr" rid="ref12 ref13">12, 13</xref>
        ], Process models [
        <xref ref-type="bibr" rid="ref14 ref15">14, 15</xref>
        ], or ArchiMate models [
        <xref ref-type="bibr" rid="ref16 ref9">9, 16</xref>
        ], on more generic conceptual
models involving the core domain concepts and their relations, is helpful in better underpinning
the models, as well as supporting the process of learning how to model [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ].
      </p>
      <p>
        Existing (text)books, such as [
        <xref ref-type="bibr" rid="ref17 ref18 ref4 ref6">17, 6, 18, 4</xref>
        ], do touch on some of these elements. However, they
generally remain ‘framed into’ conceptual modeling for database design only, while also not
providing an explicit procedure for the creation of conceptual models. One notable exception
regarding the latter is Halpin’s textbook [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] on conceptual database design, which does provide
an explicit procedure. The modeling procedure as suggested for the textbook, will certainly
build on Halpin’s work.
      </p>
      <p>We also posit that following such a grounding and specialization process will enable us
to make it more explicit to learners what the role of their ontological commitment (and the
meta-model underlying the used modeling language in particular) is in ‘painting’ their picture
of the world when they, as modelers, create a model of a domain. As such, beyond the presently
suggested textbook, we are also considering potential follow-up textbooks to specialize the
general modeling skills towards specific (classes of) modeling languages, such as (business)
process modeling and enterprise architecture modeling.</p>
      <p>Our goal with this paper is to seek feedback from the VMBO community regarding the setup
of this textbook, as well as further validate and discuss the need for such a textbook. Next to
discussing the planned content, and the underlying line of reasoning, we will also highlight our
fundamental underlying assumptions regarding modeling. In line with this, the remainder of
this paper is structured as follows. Section 2 provides an exploration of some (but not all) of
the underlying assumptions and foundational perspectives from which we will structure the
textbook. The actual planned structure is presented in section 3.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Preliminaries</title>
      <sec id="sec-2-1">
        <title>2.1. Defining the notion of conceptual (domain) model</title>
        <p>
          Without a sound understanding of what a model is, and what the act of modeling entails, it
will be dificult to teach modeling. This seems trivial, but our experience is that this is far from
the case. As such, the proposed textbook will need to start with a reflection of the concepts of
domain model and conceptual (domain) model. In line with [
          <xref ref-type="bibr" rid="ref19">19</xref>
          ], we understand a domain model
to be: “A social artifact that is understood, and acknowledged, by a collective human agent
to represent an abstraction of some domain for a particular cognitive purpose.” With domain,
we refer to ‘anything’ that one can speak and/or reflect about; i.e. the domain of interest. As
such, domain simply refers to ‘that what is being modeled’ (below we will return in more detail
regarding to the notion of the domain that is being modeled). Furthermore, the domain could be
something that already exists in the ‘real world’, something that is desired to exist in the future,
something imagined, or even something that is brought about by the existence of the model
itself. Based on this, and in line with [
          <xref ref-type="bibr" rid="ref19">19</xref>
          ], we define a conceptual model to be: “A model of a
domain, where the purpose of the model is dominated by the ambition to remain as-true-as-possible
to the original domain understanding.”
        </p>
      </sec>
      <sec id="sec-2-2">
        <title>2.2. Conceptual models as linguistic artifacts</title>
        <p>
          Requiring a model to be an artifact that needs to be understood by human agents, immediately
puts models in the realm of language. Therefore, an important theoretical foundation of domain
models is the semiotic triangle by Ogden and Richards [
          <xref ref-type="bibr" rid="ref20">20</xref>
          ], as depicted in fig. 1. The tenet of the
        </p>
        <p>.
semiotic triangle is that when we use symbols (including models) to speak about ‘something’ (a
referent), then these symbols represent (symbolize) our thoughts (thought or reference) about
that something (referent). The thought or reference is the meaning we have assigned to the
symbols. The referent can be anything, in an existing world, or in a desired/imagined world. A
domain to be modeled generally involves a complex of (related) referents, which results in a
complex of corresponding concepts/thoughts.</p>
      </sec>
      <sec id="sec-2-3">
        <title>2.3. Verbalization-based approach</title>
        <p>
          The link to the semiotic triangle, and the general communication-oriented stance, is also the
reason for using a verbalization-based approach as the starting point to learn modeling. In
doing so, we follow the so-called ‘telephone heuristic’, as coined by the fact-based modeling
approaches [
          <xref ref-type="bibr" rid="ref21 ref22 ref6">21, 22, 6</xref>
          ], as if one has to explain to someone else what a domain is about through
a telephone; or better yet, via a ‘chat’ session. In that context, it involves the formulation of
elementary facts about the domain being modeled, while being as explicit as possible. At this
point it should be noted that, as we will discuss below, there is a need to be more nuanced about
the use of the term ‘fact’. As such, we will actually prefer to speak about elementary propositions.
        </p>
        <p>From a practitioner’s perspective, providing such explicit verbalizations of one’s
understanding of a domain to be modeled may sound as a laborious task. However, we think that from a
learning perspective, explicitly articulating one’s domain understanding in terms of elementary
propositions provides a good starting point. An interesting analogy in this regards is the use
of swim-paddles when training to swim1. Such paddles enable swimmers to improve their
swimming stroke. At the same time, during an actual match, swimmers would not use them.</p>
        <p>
          Additionally, as also argued in [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ], the example elementary facts also remain useful for e.g.
validation purposes. Seeing not only the (abstract) domain model, but also example instances
on which they are based will help stakeholders to (a) understand models better, and (b) have
confidence in their correctness and usefulness.
        </p>
      </sec>
      <sec id="sec-2-4">
        <title>2.4. Domain-aware information systems – Bringing models to life</title>
        <p>In general, the ‘boxes and lines’ based models that we tend to produce in our domain are rather
‘passive’ in the sense that they just ‘sit on paper’. Unlike programming, where the program
that is being developed can already be run during its development. Therefore, even though
we argue that it is important to make it clear that conceptual modeling should not be ‘framed’
into conceptual design of databases only, we do suggest to include exercises where models
are translated to actual running software. Indeed, resulting in (diferent forms of) information
systems.</p>
        <p>However, in doing the latter, we also plan to make a distinction between (traditional)
information systems where the conceptual models are only used as a design artifact, and domain
aware information systems (DAIS), where the conceptual models are an explicit artifact in
the information system. An example of such domain aware information systems are
processaware information systems which do not just ‘log’ the execution of processes, but pro-actively
monitor/direct their execution based on the process models.</p>
      </sec>
      <sec id="sec-2-5">
        <title>2.5. Awareness of one’s ontological commitment</title>
        <p>
          As mentioned before, we also aim to make learners aware of their/the-used ontological
commitment (meta-model or conceptualization), in relation to the modeling purpose. In [
          <xref ref-type="bibr" rid="ref23 ref9">9, 23</xref>
          ],
this thinking is ‘boot strapped’ by discussing how a modeler mentally ‘paints a picture of the
world’ in terms of available kinds of elements. This process is illustrated in fig. 2. On the left,
we see a situation where the viewer/modeler can only paint a picture of the world in terms
of ‘elements’. Having only elements to paint this picture is not useful, as one cannot express
relations between the elements. On the right, the viewer/modeler can paint this picture in terms
of ‘entities’ and ‘relations’2. This then, allows the viewer/modeler to capture entities and their
relations. This, however, does not allow one to speak about classes and types of things that may
have common properties and rules. So, a next step, in the context of this illustration, would be
to introduce a type-instance distinction as a special kind of relation.
        </p>
        <p>
          This process of a step-wise refinement of the ontological commitment, is actually also used
in clarifying the anatomy [
          <xref ref-type="bibr" rid="ref16">16</xref>
          ] of the ArchiMate language as illustrated in fig. 3.
1https://www.yourswimlog.com/ultimate-guide-swim-paddles/
2In retrospect, erroneously referred to as relationships in this diagram
Conception
Viewer’s "picture of the universe"
Viewer’s "picture of the universe"
conceiving
conceiving
Viewer
perceiving
        </p>
        <p>Elements
Universe</p>
        <p>Viewer</p>
        <p>Entities Relationships
perceiving</p>
        <p>Universe</p>
      </sec>
      <sec id="sec-2-6">
        <title>2.6. Focus on the core skills</title>
        <p>The proposed textbook will focus on the core skills involved in conceptual modeling. Basically
involving the conscious, and controlled, creation and externalization (i.e. capturing as a social
artifact) of an abstraction of a domain.</p>
        <p>In real-world situations, the purpose of a model, especially in terms of scoping, level of detail,
intended use, etc, are important and will have a major impact on the requirements one puts on
the model, and ultimately the tasks involved in creating the model. In this textbook, however,
the focus is on learning the core skills involved in the act of modeling. In the aforementioned
(potential) follow up textbooks on e.g. process modeling and enterprise architecture, we will be
able to more explicitly add the purpose dimension.</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Suggested outline of the textbook</title>
      <p>The suggested textbook would start with a discussion of the preliminaries. After that we suggest
to follow four stages in teaching (and doing) modeling: (1) explore a domain and operationalize
the models, (2) ground the resulting understanding on a foundational ontology, (3) manage (in
line with the model’s purpose) the complexity of the resulting model, and (4) use the model as a
base for more purpose/domain specific models (e.g. BPMN, DEMO, and ArchiMate models.).</p>
      <p>The modeling process as followed in specific real world contexts may follow a diferent
(e.g. more cyclic) order. However, at the same time, it is important to refer back to the earlier
referenced analogy regarding the use of ‘swim-paddles’ when improving one’s swimming stroke.
As such, we do posit that the suggested order is a good order to follow when ‘still’ learning how
to model. Furthermore, we argue that the four stages provide a natural progression in priorities
(explore the domain, grounding of the model, manage complexity, and specialize the model
towards specific purposes).</p>
      <sec id="sec-3-1">
        <title>3.1. Motivation for conceptual modeling</title>
        <p>Before embarking on the journey to learn conceptual modeling, it makes sense to create some
awareness of the things that could go wrong when conceptual models are left implicit or badly
structured.</p>
        <p>This could involve the discussion of some examples and cases, but can also involve some
exercises of what may happen if the conceptual model is e.g. left implicit.</p>
      </sec>
      <sec id="sec-3-2">
        <title>3.2. Preliminaries</title>
        <p>We would start the journey on learning how to model with a a general positioning (and
philosophic orientation) of the key notions as used in the book.</p>
        <p>Learners are likely to already have a basic, if only at an informal level, understanding of what
a model is. We, therefore, plan to start with a reflection on the definition of domain model, and
conceptual (domain) model in particular. In line with the discussion in section 2, we would also
use the semiotic triangle (fig. 1) to better position the creation, and use of, conceptual models as
being linguistic acts, while also stressing the inter-subjectivity in which models are embedded.</p>
        <p>Finally, we would lay the foundation of the learners’ awareness of their ontological
commitments, by which they will ‘paint their pictures of the world’ in line with fig. 2.</p>
        <p>We also plan to reiterate some of the consequences of the philosophic orientation in the
later chapters of the textbook, to make things more concrete along the way. For instance, by
clarifying that they are using an increasingly more specific ontological commitment by which
they ‘paint their pictures of the world’ (see fig. 2).</p>
        <sec id="sec-3-2-1">
          <title>Exercises for learners would involve:</title>
          <p>• Basic questions regarding the semiotic triangle.
• Basic questions regarding the notion of model.</p>
          <p>• Basic questions regarding the role of ontological commitments.</p>
        </sec>
      </sec>
      <sec id="sec-3-3">
        <title>3.3. Stage 1 – Creating an initial conceptual model</title>
        <p>
          In learning to create the initial conceptual model, students will need to first follow a series of
steps. The planned text book would discuss each of these steps.
3.3.1. Verbalize domain abstractions
In this step, students would need to verbalize, using the aforementioned telephone/chat heuristic,
formulate elementary propositions about the domain they are to model. The elementary in this
context refers to the need to ensure that each proposition is formulated in such a way that it
cannot be split further without loosing information. For instance, the proposition “John smokes
and drives the car with license plate 925 DJX” is not elementary as it can (normally) be split into
“John smokes” and “John drives the car with license plate 925 DJX”. In this context, fact-based
modeling approaches actually speak about elementary facts. However, since we suggest to treat
the identification of truth-makers as a specific step in the modeling process, we prefer to first
speak about elementary propositions before we can speak about elementary facts.
Exercises for learners would involve:
• Identify and reflect on the specific scope of the domain to be modeled and the purpose
for which the model is created.
• Identify if a given example verbalization is elementary or not.
• Given a text describing a domain and/or set of tables reporting on sample instances from
a domain, express this in terms of elementary propositions.
3.3.2. Identify typing
In principle, this step follows the flow as suggested in most fact-based modeling approaches.
Given a set of elementary propositions, one can look for types and their (example) extensions.
Symmetric to what happens in database design, this also involves defining how we can refer
to/uniquely identify individuals (i.e. the counterpart of the information principle and the closed
world assumption). In the context of conceptual database design [
          <xref ref-type="bibr" rid="ref6">6</xref>
          ] examples would be Person
John fueled Car 925 DJX, Person Paula fueled Car 254 AZI, and Car LH 62 GV fueled by Person
Jim. This would lead to the object types Person, John, and Car, and finally the proposition type
Person ... fueled Car ....
        </p>
        <sec id="sec-3-3-1">
          <title>Exercises for learners would involve:</title>
          <p>• For a given set of elementary proposition, identify the proposition types.
• For a given domain description (and example instances), execute the modeling steps as
discussed so-far.
3.3.3. Clarify how we may refer to individual instances
The next step would be to make explicit how we may refer to the individual things in the domain.
In many situations this involves some ‘string’ or ‘number’. For instance, a person name, a social
number, a license plate number, a bank account number, etc.</p>
          <p>However, in a general sense, one cannot always assume to have an ‘identifier’ to refer to
specific things. For instance, we may observe Person Erik Proper took a photo of some Elephant,
as well as Person Hans van Wijck took a photo of some Elephant. with as the underlying
proposition type Person ... took a photo of Elephant ... In these verbalizations of the instances,
the “some” in “some Elephant” acknowledges the fact that the observed situation involved a
specific elephant, but that we do not have an identifier for said elephant.</p>
          <p>When using conceptual models in a database design context, such situations are frowned
upon, as one would like to know which elephant to enable the storage of the fact in a database.
In such case, one is forced to either introduce such an identification, or treat the observation as
a unary proposition type: Person Hans van Wijck took a photo of an Elephant and/or switch
to a more generic interpretation: Person Hans van Wijck took a photo of an Animal of Kind
elephant. In this case, the resulting model is not a conceptual model of the full domain, but
rather, but a conceptual model of the way the domain will be reported on in the database.</p>
        </sec>
        <sec id="sec-3-3-2">
          <title>Exercises for learners would involve:</title>
          <p>• For a given domain description, given example instances, identified object types and
proposition types, identify the way we would/could refer to the instances.
• Even though we want learners to understand the applicability of conceptual modeling
to be broader than database design, it does make sense to let learners ‘play’ with some
database exercises.</p>
          <p>This should certainly involve SQL related exercises, but could also include e.g. Prolog or
Datalog related exercises.</p>
          <p>
            Even more, for more advanced groups of students, one could use a (knowledge) graph
database related exercises to also operationalize the domain aware aspect of information
systems, connecting the (graph representation of the) conceptual model to its instances.
• For a given domain description (and example instances), execute the modeling steps as
discussed so-far.
3.3.4. Create a graphical representation, and conduct a population check
Using the object and proposition types identified so-far, students can create a first graphical
representation of the conceptual model. We suggest to use an ORM-alike notation [
            <xref ref-type="bibr" rid="ref6">6</xref>
            ] that
allows for the inclusion of example instances (possibly involving anonymized instances as in
some Elephant) in the graphical representation, to enable validation of the structure of the
model as well as possible rules on the domain. Adding, and reflecting on, the example instances
enables a population check to see if the ‘fabric’ of the present version of conceptual model
accommodates the example instances.
          </p>
          <p>Exercises for learners would involve:
• For a set of object types and proposition types, and a set of example instances, create a
graphical representation, and reflect on the correctness (e.g. elementarity) of the resulting
model.
3.3.5. From propositions to facts
The next step is to have students reflect on truth makers. For each of the object types the
learners need to reflect on the criteria that determine the truth-of-existence of its instances. In
the case of proposition types, this involves the identification of criteria that make its instances
true or not. These truth-makers need to be added to the conceptual model. This reflection may
also lead to refinements of the model as it stands so-far.</p>
        </sec>
        <sec id="sec-3-3-3">
          <title>Exercises for learners would involve:</title>
          <p>
            • For a domain description, and an associated set of object types and proposition types,
determine the truth makers.
• For a given domain description (and example instances), execute the modeling steps as
discussed so-far.
3.3.6. Adding domain rules
This step involves the identification of rules. In terms of [
            <xref ref-type="bibr" rid="ref24">24</xref>
            ] this can involve both alethic rules
and deontic rules. Alethic rules (including derivation rules) involve necessities, which cannot,
even in principle, be violated by, typically because of some physical or logical law. Deontic
rules involve obligations, which may be violated, even though they ought not.
          </p>
          <p>An example of an alethic rule is: no person is a parent of themselves. Two examples of a
deontic rule are: each person who teaches at a University ought to have a Doctorate, and
each person who drives a car must have a valid drivers’ license.</p>
          <p>
            This introduction of such domain rules, will involve both graphical representation of rules,
as well as SBVR-based [
            <xref ref-type="bibr" rid="ref25">25</xref>
            ] rules in a semi-natural language format.
          </p>
          <p>Reflecting on such rules, may also lead to further refinement of the conceptual model. For
instance, leading to the nuance of a person having a drivers’ license, versus having a valid
driver’s license.</p>
        </sec>
        <sec id="sec-3-3-4">
          <title>Exercises for learners would involve:</title>
          <p>
            • For a domain description, an associated set of object types and proposition types, as well
as a textual description of alethic/deontic rules, formulate these rules in
graphical/SBVRbased format.
3.3.7. Allowing for – instance level – changes in the domain
The modeling steps so-far have ignored the question of possible changes in the domain that
is being modeled. Propositions/facts may change over time. The goal of this step is to add a
time dimension to the conceptual model, also requiring a temporal extension to the elementary
propositions, with associated refinements. For example, the earlier example of John and Paula
fueling (their) cars, could now be refined to the following ‘log book’ [
            <xref ref-type="bibr" rid="ref26">26</xref>
            ]3 that reports on events
that happen:
          </p>
          <p>Person John fueling Car 925 DJX STARTED AT 22.03.2023 10:51:20
Person John fueling Car 925 DJX ENDED AT 22.03.2023 10:53:29
Person Paula fueling Car 254 AZI STARTED AT 22.03.2023 10:52:12</p>
          <p>Person Paula fueling Car 254 AZI ENDED AT 22.03.2023 10:55:29
Adding a temporal ordering in which events occur, also enables the introduction of history
related domain rules. For instance: When a person fuels some car at some point in time, then
that person should own that car at that same point in time.</p>
        </sec>
        <sec id="sec-3-3-5">
          <title>Exercises for learners would involve:</title>
          <p>• Given a log of facts that occurred in a domain, show the conceptual domain model and
its ‘population’ at various points in time and reflect on the model evolution.
• Express some history related rules in an SBVR like format.</p>
        </sec>
      </sec>
      <sec id="sec-3-4">
        <title>3.4. Stage 2 – Ontological grounding</title>
        <p>The use of (foundational) ontologies allows modelers (and learners) to develop semantically
sounder models. Such ontological grounding would entail ‘stereotyping’ the elements from the
conceptual domain model in terms of foundational classes. As an example, the cars that have
been used as an example several times in this paper could be tagged as being kinds of things (in
the OntoUML sense).</p>
        <p>By attempting to link the model elements to a conceptually sound ontology (e.g. UFO [27]) we
do more than simply enrich the model; it also ofers benefits in terms of creating a conceptual
model that is sound (conforming to ontological commitment that fits with the rules specific by
the ontological model). For example, we could discover that our model has a ‘specialization’ that,
according to the ontological constraints, is not allowed. It could also be that we have defined
a concepts (performer, which is a person, and band, which is a group of persons/people) and
failed to identify the fact that they may belong to a mixin-type (performer-artist) that allows us
to reason about both types of performers in a consistent manner.</p>
        <p>At the end of this stage, we can also reflect on the possible iterative process flow during actual
modeling assignments. When developing the initial model there is, of course, no objection
to already provide the grounding on a foundational ontology ‘as one goes along’. As long
as this ‘grounding’ (depth first) does not hamper modelers in ‘exploring’ (breadth first) their
understanding of the domain. As such, during stage 1, the priority has to remain on exploring the
domain, while in stage 2 this shifts to grounding the resulting domain model on a foundational
ontology.</p>
        <p>Exercises for learners would involve:
3This involves actually an interesting modeling approach to reflect on in relation to the ‘process logs’ as presently
used in the context of process mining.</p>
        <p>• Given a conceptual domain model at a certain point in time, take four related model
elements and ‘tag’ them with their ontological class. Explain your choices.
• Given a log of facts that occurred in a domain and the associated model evolution, reflect
on the notion of (p)endurants.</p>
      </sec>
      <sec id="sec-3-5">
        <title>3.5. Stage 3 – Managing complexity of domains</title>
        <p>Novice modelers tend to struggle with conceptual modeling for several reasons. In teaching
diferent modeling approaches, we have noticed that the number of model elements as ofered
by a modeling language may cause major problems in learning the basic skills of modeling.
Furthermore, if the domain scope is large – meaning that modeling it would lead to many
concepts and relationships – it can also be daunting to oversee what is going on. Simple rules
such as ‘start small’ are not really helpful in such situations as they ofer little practical guidance.</p>
        <p>There are several strategies that we will include in this part of the proposed book. Producing
a definite list would certainly be part of future. Nevertheless, some options include: a) strategies
for (functional) decomposition of a domain with a high level of complexity, allowing modelers
to tackle one part of the domain at a time, b) strategies to start with a very coarse-grained model
and step-wise refinement to tackle complex domains, and</p>
        <sec id="sec-3-5-1">
          <title>Exercises for learners would involve:</title>
          <p>• Applying diferent techniques to manage the complexity of a (conceptual model of a)
domain.</p>
        </sec>
      </sec>
      <sec id="sec-3-6">
        <title>3.6. Stage 4 – Linkage to more specific modeling languages</title>
        <p>
          In this last stage, we will show the learners how to use the resulting conceptual models as a
base to develop (and ground) more specific models, based on earlier work in the context of e.g.
UML [
          <xref ref-type="bibr" rid="ref10 ref11">10, 11</xref>
          ], System Dynamics [
          <xref ref-type="bibr" rid="ref12 ref13">12, 13</xref>
          ], Process Modeling [
          <xref ref-type="bibr" rid="ref14 ref15">14, 15</xref>
          ], and ArchiMate [
          <xref ref-type="bibr" rid="ref16 ref9">9, 16</xref>
          ].
        </p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Conclusion References</title>
      <p>In this paper we provided the outline of a planned textbook on conceptual modeling, targeting
learners of conceptual modeling in general, and bachelor-level students in particular. As stated
in the introduction, our goal with this paper is to seek feedback regarding the setup of this
textbook, as well as further validate the need for such a textbook.
on Logbooks, The Computer Journal 39 (1996) 793–799.
[27] G. Guizzardi, G. Wagner, J. P. A. Almeida, R. Guizzardi, Towards Ontological Foundations
for Conceptual Modeling: The Unified Foundational Ontology (UFO) Story, Applied
Ontology 10 (2015) 259–271. doi:10.3233/AO-150157.
[28] T. A. Halpin, J. Krogstie, H. A. Proper (Eds.), Proceedings of the 13th Workshop on Exploring
Modeling Methods for Systems Analysis and Design (EMMSAD 2008), Held in Conjunction
with the 20th Conference on Advanced Information Systems Engineering (CAiSE 2008),
Montpellier, France, volume 337, CEUR-WS.org, 2008. URL: http://ceur-ws.org/Vol-337.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <surname>M. M. Lankhorst</surname>
            ,
            <given-names>F.</given-names>
          </string-name>
          <string-name>
            <surname>Arbab</surname>
            ,
            <given-names>S. F.</given-names>
          </string-name>
          <string-name>
            <surname>Bekius</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          <string-name>
            <surname>Bonsangue</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          <string-name>
            <surname>Bosma</surname>
            ,
            <given-names>J.</given-names>
          </string-name>
          <string-name>
            <surname>Campschroer</surname>
            ,
            <given-names>M. J.</given-names>
          </string-name>
          <string-name>
            <surname>Cuvelier</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          <string-name>
            <surname>Fennema</surname>
            ,
            <given-names>L.</given-names>
          </string-name>
          <string-name>
            <surname>Groenewegen</surname>
            ,
            <given-names>S. J. B. A.</given-names>
          </string-name>
          <string-name>
            <surname>Hoppenbrouwers</surname>
          </string-name>
          ,
          <string-name>
            <surname>M.-E. Iacob</surname>
            ,
            <given-names>W. P. M.</given-names>
          </string-name>
          <string-name>
            <surname>Janssen</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          <string-name>
            <surname>Jonkers</surname>
            ,
            <given-names>D.</given-names>
          </string-name>
          <string-name>
            <surname>Krukkert</surname>
            ,
            <given-names>P.</given-names>
          </string-name>
          <string-name>
            <surname>Penders</surname>
            ,
            <given-names>H. A.</given-names>
          </string-name>
          <string-name>
            <surname>Proper</surname>
            ,
            <given-names>R. J.</given-names>
          </string-name>
          <string-name>
            <surname>Slagter</surname>
            ,
            <given-names>A. W.</given-names>
          </string-name>
          <string-name>
            <surname>Stam</surname>
            ,
            <given-names>M. W. A.</given-names>
          </string-name>
          <string-name>
            <surname>Steen</surname>
            ,
            <given-names>R. J.</given-names>
          </string-name>
          <string-name>
            <surname>Wieringa</surname>
          </string-name>
          , F. S. de Boer, H. W. L. ter
          <string-name>
            <surname>Doest</surname>
          </string-name>
          , R. van Buuren, P. A. T. van
          <string-name>
            <surname>Eck</surname>
            ,
            <given-names>D. van Leeuwen</given-names>
          </string-name>
          , L. van der Torre,
          <string-name>
            <surname>G. E. Veldhuijzen van Zanten</surname>
          </string-name>
          ,
          <source>Enterprise Architecture at Work - Modelling, Communication and Analysis</source>
          ,
          <source>The Enterprise Engineering Series</source>
          , 3rd ed., Springer, Heidelberg, Germany,
          <year>2013</year>
          . doi:
          <volume>10</volume>
          .1007/978-3-
          <fpage>642</fpage>
          -29651-2.
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <surname>M.-E. Iacob</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          <string-name>
            <surname>Jonkers</surname>
          </string-name>
          ,
          <string-name>
            <surname>M. M. Lankhorst</surname>
            ,
            <given-names>H. A.</given-names>
          </string-name>
          <string-name>
            <surname>Proper</surname>
            ,
            <given-names>D. A. C.</given-names>
          </string-name>
          <string-name>
            <surname>Quartel</surname>
          </string-name>
          , ArchiMate
          <volume>2</volume>
          .1 Specification, The Open Group,
          <year>2013</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <given-names>OMG</given-names>
            ,
            <surname>Business Process Modeling Notation (BPMN) Specification</surname>
          </string-name>
          , Version
          <volume>1</volume>
          .1,
          <source>Technical Report formal/2008-01-17</source>
          , Object Management Group, Needham, Massachusetts,
          <year>2008</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <given-names>J. L. G.</given-names>
            <surname>Dietz</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H. B. F.</given-names>
            <surname>Mulder</surname>
          </string-name>
          ,
          <article-title>Enterprise Ontology - A Human-Centric Approach to Understanding the Essence of Organisation</article-title>
          , The Enterprise Engineering Series, Springer, Cham,
          <year>2020</year>
          . doi:
          <volume>10</volume>
          .1007/978-3-
          <fpage>030</fpage>
          -38854-6.
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>J.</given-names>
            <surname>Gordijn</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H.</given-names>
            <surname>Akkermans</surname>
          </string-name>
          , Value Based Requirements Engineering: Exploring Innovative
          <string-name>
            <surname>e-Commerce</surname>
            <given-names>Ideas</given-names>
          </string-name>
          ,
          <source>Requirements Engineering Journal</source>
          <volume>8</volume>
          (
          <year>2003</year>
          )
          <fpage>114</fpage>
          -
          <lpage>134</lpage>
          . doi:
          <volume>10</volume>
          .1007/ s00766-003-0169-x.
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <given-names>T. A.</given-names>
            <surname>Halpin</surname>
          </string-name>
          , Information Modeling and
          <article-title>Relational Databases, from Conceptual Analysis to Logical Design</article-title>
          , Morgan Kaufmann, San Mateo, California,
          <year>2001</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          , G. Guizzardi,
          <article-title>Modeling for Enterprises; Let's Go to RoME ViA RiME</article-title>
          , in: T. Clark,
          <string-name>
            <given-names>S.</given-names>
            <surname>Zschaler</surname>
          </string-name>
          ,
          <string-name>
            <given-names>B.</given-names>
            <surname>Barn</surname>
          </string-name>
          ,
          <string-name>
            <surname>K.</surname>
          </string-name>
          Sandkuhl (Eds.),
          <source>Proceedings of the Forum at Practice of Enterprise Modeling</source>
          <year>2022</year>
          (
          <article-title>PoEM-Forum</article-title>
          <year>2022</year>
          )
          <article-title>Co-Located with PoEM 2022</article-title>
          , London, United Kingdom,
          <source>November 23-25</source>
          ,
          <year>2022</year>
          , volume
          <volume>3327</volume>
          , CEUR-WS.org,
          <year>2022</year>
          , pp.
          <fpage>4</fpage>
          -
          <lpage>15</lpage>
          . URL: https://ceur-ws.
          <source>org/</source>
          Vol-
          <volume>3327</volume>
          /paper02.pdf.
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [8]
          <string-name>
            <given-names>D.</given-names>
            <surname>Aveiro</surname>
          </string-name>
          , G. Guizzardi,
          <string-name>
            <given-names>S.</given-names>
            <surname>Guerreiro</surname>
          </string-name>
          , W. Guédria (Eds.), Advances in Enterprise Engineering XII - 8th Enterprise Engineering Working Conference,
          <string-name>
            <surname>EEWC</surname>
          </string-name>
          <year>2018</year>
          , Luxembourg, May 28 - June 1,
          <year>2018</year>
          , Proceedings, volume
          <volume>334</volume>
          <source>of Lecture Notes in Business Information Processing</source>
          , Springer, Heidelberg, Germany,
          <year>2018</year>
          . doi:
          <volume>10</volume>
          .1007/978-3-
          <fpage>030</fpage>
          -06097-8.
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [9]
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          ,
          <source>Foundations of Work-Systems Modeling, Lecture Notes</source>
          , Radboud University, Nijmegen, The Netherlands, Nijmegen, The Netherlands,
          <year>2006</year>
          . URL: https: //www.erikproper.eu/publications/proper2006worksystemsmodeling.pdf. doi:
          <volume>10</volume>
          .48550/ ARXIV.2401.16221.
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [10]
          <string-name>
            <given-names>A. I.</given-names>
            <surname>Bleeker</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. J. B. A.</given-names>
            <surname>Hoppenbrouwers</surname>
          </string-name>
          ,
          <article-title>The Role of Concept Management in System Development - a Practical and a Theoretical Perspective</article-title>
          , in: J.
          <string-name>
            <surname>Grabis</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          <string-name>
            <surname>Persson</surname>
          </string-name>
          , J. Stirna (Eds.),
          <source>Forum Proceedings of the 16th Conference on Advanced Information Systems</source>
          <year>2004</year>
          (CAiSE
          <year>2004</year>
          ), Riga, Latvia, Faculty of Computer Science and Information Technology, Riga, Latvia,
          <year>2004</year>
          , pp.
          <fpage>73</fpage>
          -
          <lpage>82</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [11]
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          ,
          <string-name>
            <given-names>A. I.</given-names>
            <surname>Bleeker</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. J. B. A.</given-names>
            <surname>Hoppenbrouwers</surname>
          </string-name>
          ,
          <article-title>Object-Role Modeling as a Domain Modeling Approach</article-title>
          , in: J.
          <string-name>
            <surname>Grundspenkis</surname>
          </string-name>
          , M. Kirikova (Eds.),
          <source>CAiSE'04 Workshops in Connection with the 16th Conference on Advanced Information Systems Engineering</source>
          , Riga, Latvia,
          <fpage>7</fpage>
          -
          <lpage>11</lpage>
          June,
          <year>2004</year>
          ,
          <article-title>Knowledge and Model Driven Information Systems Engineering for Networked Organisations</article-title>
          ,
          <source>Proceedings</source>
          , Vol.
          <volume>1</volume>
          , volume
          <volume>3</volume>
          , Faculty of Computer Science and Information Technology, Riga, Latvia,
          <year>2004</year>
          , pp.
          <fpage>317</fpage>
          -
          <lpage>328</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          [12]
          <string-name>
            <given-names>F. P.</given-names>
            <surname>Tulinayo</surname>
          </string-name>
          , P. van Bommel,
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          ,
          <article-title>Grounded System Dynamics: A Procedure for Underpinning System Dynamics with a Domain Modeling Method</article-title>
          , in: P. Johannesson,
          <string-name>
            <given-names>J.</given-names>
            <surname>Krogstie</surname>
          </string-name>
          ,
          <string-name>
            <surname>A. L.</surname>
          </string-name>
          Opdahl (Eds.),
          <source>The Practice of Enterprise Modeling - 4th IFIP WG 8</source>
          .1 Working Conference, PoEM 2011 Oslo, Norway, November 2-
          <issue>3</issue>
          ,
          <source>2011 Proceedings, volume 92 of Lecture Notes in Business Information Processing</source>
          , Springer, Heidelberg, Germany,
          <year>2011</year>
          , pp.
          <fpage>112</fpage>
          -
          <lpage>125</lpage>
          . doi:
          <volume>10</volume>
          .1007/978-3-
          <fpage>642</fpage>
          -24849-
          <issue>8</issue>
          _
          <fpage>9</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [13]
          <string-name>
            <given-names>F. P.</given-names>
            <surname>Tulinayo</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. J. B. A.</given-names>
            <surname>Hoppenbrouwers</surname>
          </string-name>
          ,
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          ,
          <article-title>Integrating System Dynamics with Object-Role Modeling</article-title>
          , in: J.
          <string-name>
            <surname>Stirna</surname>
            ,
            <given-names>A</given-names>
          </string-name>
          . Persson (Eds.),
          <source>The Practice of Enterprise Modeling, First IFIP WG 8</source>
          .1 Working Conference,
          <source>PoEM</source>
          <year>2008</year>
          , Stockholm, Sweden,
          <source>November 12-13</source>
          ,
          <year>2008</year>
          . Proceedings, volume
          <volume>15</volume>
          <source>of Lecture Notes in Business Information Processing</source>
          , Springer Berlin Heidelberg, Berlin, Heidelberg,
          <year>2008</year>
          , pp.
          <fpage>77</fpage>
          -
          <lpage>85</lpage>
          . doi:
          <volume>10</volume>
          .1007/978-3-
          <fpage>540</fpage>
          -89218-
          <issue>2</issue>
          _
          <fpage>6</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [14]
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. J. B. A.</given-names>
            <surname>Hoppenbrouwers</surname>
          </string-name>
          , T. P.
          <string-name>
            <surname>van der Weide</surname>
            ,
            <given-names>A</given-names>
          </string-name>
          <string-name>
            <surname>Fact-Oriented Approach</surname>
          </string-name>
          to Activity Modeling, in: R.
          <string-name>
            <surname>Meersman</surname>
            ,
            <given-names>Z.</given-names>
          </string-name>
          <string-name>
            <surname>Tari</surname>
          </string-name>
          , P. Herrero (Eds.),
          <source>On the Move to Meaningful Internet Systems</source>
          <year>2005</year>
          :
          <article-title>OTM 2005 Workshops, OTM Confederated International Workshops</article-title>
          and Posters, AWeSOMe, CAMS, GADA, MIOS+INTEROP, ORM, PhDS, SeBGIS, SWWS, and
          <source>WOSE</source>
          <year>2005</year>
          ,
          <string-name>
            <given-names>Agia</given-names>
            <surname>Napa</surname>
          </string-name>
          , Cyprus,
          <source>October 31 - November 4</source>
          ,
          <year>2005</year>
          , Proceedings, volume
          <volume>3762</volume>
          of Lecture Notes in Computer Science, Springer, Heidelberg, Germany,
          <year>2005</year>
          , pp.
          <fpage>666</fpage>
          -
          <lpage>675</lpage>
          . doi:
          <volume>10</volume>
          .1007/11575863_
          <fpage>86</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref15">
        <mixed-citation>
          [15]
          <string-name>
            <surname>P. van Bommel</surname>
            ,
            <given-names>S. J. B. A.</given-names>
          </string-name>
          <string-name>
            <surname>Hoppenbrouwers</surname>
            ,
            <given-names>H. A.</given-names>
          </string-name>
          <string-name>
            <surname>Proper</surname>
            ,
            <given-names>T. P. van der Weide</given-names>
          </string-name>
          ,
          <article-title>On the Use of Object-Role Modelling to Model Active Domains</article-title>
          , in: [28],
          <year>2008</year>
          , pp.
          <fpage>473</fpage>
          -
          <lpage>484</lpage>
          . URL: http://ceur-ws.
          <source>org/</source>
          Vol-
          <volume>337</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref16">
        <mixed-citation>
          [16]
          <string-name>
            <surname>M. M. Lankhorst</surname>
            ,
            <given-names>H. A.</given-names>
          </string-name>
          <string-name>
            <surname>Proper</surname>
            ,
            <given-names>H.</given-names>
          </string-name>
          <string-name>
            <surname>Jonkers</surname>
          </string-name>
          ,
          <article-title>The Anatomy of the ArchiMate Language:</article-title>
          ,
          <source>International Journal of Information System Modeling and Design</source>
          <volume>1</volume>
          (
          <year>2010</year>
          )
          <fpage>1</fpage>
          -
          <lpage>32</lpage>
          . doi:
          <volume>10</volume>
          . 4018/jismd.2010092301.
        </mixed-citation>
      </ref>
      <ref id="ref17">
        <mixed-citation>
          [17]
          <string-name>
            <given-names>R.</given-names>
            <surname>Elmasri</surname>
          </string-name>
          ,
          <string-name>
            <given-names>S. B.</given-names>
            <surname>Navathe</surname>
          </string-name>
          ,
          <source>Fundamentals of Database Systems</source>
          , 2nd ed.,
          <string-name>
            <surname>Benjamin</surname>
            <given-names>Cummings</given-names>
          </string-name>
          , Redwood City, California,
          <year>1994</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref18">
        <mixed-citation>
          [18]
          <string-name>
            <given-names>A.</given-names>
            <surname>Olivé</surname>
          </string-name>
          ,
          <source>Conceptual Modeling of Information Systems</source>
          , Springer, Heidelberg, Germany,
          <year>2007</year>
          . doi:
          <volume>10</volume>
          .1007/978-3-
          <fpage>540</fpage>
          -39390-0.
        </mixed-citation>
      </ref>
      <ref id="ref19">
        <mixed-citation>
          [19]
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          , G. Guizzardi, On Domain Conceptualization, in: D.
          <string-name>
            <surname>Aveiro</surname>
            , G. Guizzardi,
            <given-names>R.</given-names>
          </string-name>
          <string-name>
            <surname>Pergl</surname>
            ,
            <given-names>H. A.</given-names>
          </string-name>
          <string-name>
            <surname>Proper</surname>
            (Eds.), Advances in Enterprise Engineering XIV - 10th Enterprise Engineering Working Conference,
            <given-names>EEWC</given-names>
          </string-name>
          <year>2020</year>
          ,
          <article-title>Bozen-</article-title>
          <string-name>
            <surname>Bolzano</surname>
          </string-name>
          , Italy, September 28,
          <string-name>
            <surname>October</surname>
            <given-names>19</given-names>
          </string-name>
          , and November 9-
          <issue>10</issue>
          ,
          <year>2020</year>
          , Revised Selected Papers, volume
          <volume>411</volume>
          <source>of Lecture Notes in Business Information Processing</source>
          , Springer, Heidelberg, Germany,
          <year>2021</year>
          , pp.
          <fpage>49</fpage>
          -
          <lpage>69</lpage>
          . doi:
          <volume>10</volume>
          .1007/978-3-
          <fpage>030</fpage>
          -74196-
          <issue>9</issue>
          _
          <fpage>4</fpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref20">
        <mixed-citation>
          [20]
          <string-name>
            <surname>C. K. Ogden</surname>
            ,
            <given-names>I. A.</given-names>
          </string-name>
          <string-name>
            <surname>Richards</surname>
          </string-name>
          ,
          <article-title>The Meaning of Meaning - A Study of the Influence of Language upon Thought and of the Science of Symbolism</article-title>
          , Magdalene College, University of Cambridge, Oxford, United Kingdom,
          <year>1923</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref21">
        <mixed-citation>
          [21]
          <string-name>
            <given-names>S.</given-names>
            <surname>Nijssen</surname>
          </string-name>
          ,
          <string-name>
            <given-names>T. A.</given-names>
            <surname>Halpin</surname>
          </string-name>
          , Conceptual Schema and
          <string-name>
            <surname>Relational Database Design: A Fact Oriented</surname>
            <given-names>Approach</given-names>
          </string-name>
          , Prentice Hall, Englewood Clifs, New Jersey,
          <year>1989</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref22">
        <mixed-citation>
          [22]
          <string-name>
            <given-names>G.</given-names>
            <surname>Bakema</surname>
          </string-name>
          ,
          <string-name>
            <given-names>J. P.</given-names>
            <surname>Zwart</surname>
          </string-name>
          , H. van der Lek, Volledig Communicatiegeoriënteerde Informatiemodellering, Kluwer, Deventer, The Netherlands,
          <year>1996</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref23">
        <mixed-citation>
          [23]
          <string-name>
            <given-names>H. A.</given-names>
            <surname>Proper</surname>
          </string-name>
          , Grounded Enterprise Modelling, DaVinci Series, Nijmegen Institute for Information and Computing Sciences, Radboud University, Nijmegen, The Netherlands,
          <year>2008</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref24">
        <mixed-citation>
          [24]
          <string-name>
            <given-names>T. A.</given-names>
            <surname>Halpin</surname>
          </string-name>
          , Business Rule Modality, in: [28],
          <year>2008</year>
          , pp.
          <fpage>383</fpage>
          -
          <lpage>394</lpage>
          . URL: http://ceur-ws.
          <source>org/</source>
          Vol-
          <volume>337</volume>
          .
        </mixed-citation>
      </ref>
      <ref id="ref25">
        <mixed-citation>
          [25]
          <string-name>
            <surname>OMG</surname>
          </string-name>
          ,
          <article-title>Semantics of Business Vocabulary and Rules (SBVR)</article-title>
          ,
          <source>Technical Report dtc/06 - 03 - 02</source>
          , Object Management Group, Needham, Massachusetts,
          <year>2006</year>
          .
        </mixed-citation>
      </ref>
      <ref id="ref26">
        <mixed-citation>
          [26]
          <string-name>
            <surname>P. van Bommel</surname>
          </string-name>
          ,
          <string-name>
            <given-names>P. J. M.</given-names>
            <surname>Frederiks</surname>
          </string-name>
          ,
          <string-name>
            <surname>T. P. van der Weide</surname>
          </string-name>
          , Object - Oriented Modeling Based
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>