Service-Oriented Coordination Platform for
Technology-Enhanced Learning
Boris Shishkov
1
and Marten van Sinderen
2
1
IICREST / Delft University of Technology – TBM, Jaffalaan 5
2628 BX Delft, The Netherlands
b.b.shishkov@iicrest.eu, b.b.shishkov@tudelft.nl
2
University of Twente – EEMCS, Drienerlolaan 5
7500 AE Enschede, The Netherlands
m.j.vansinderen@ewi.utwente.nl
Abstract. It is currently difficult to coordinate learning processes, not only
because multiple stakeholders are involved (such as students, teachers,
administrative staff, technical staff), but also because these processes are driven
by sophisticated rules (such as rules on how to provide learning material, rules
on how to assess students’ progress, rules on how to share educational
responsibilities). This is one of the reasons for the slow progress in technology-
enhanced learning. Consequently, there is a clear demand for technological
facilitation of the coordination of learning processes. In this work, we suggest
some solution directions that are based on SOA (Service-Oriented
Architecture). In particular, we propose a coordination service pattern
consistent with SOA and based on requirements that follow from an analysis of
both learning processes and potentially useful support technologies. We present
the service pattern considering both functional and non-functional issues, and
we address policy enforcement as well. Finally, we complement our proposed
architecture-level solution directions with an example. The example illustrates
our ideas and is also used to identify: (i) a short list of educational IT services;
(ii) related non-functional concerns; they will be considered in future work.
Keywords. e-Learning, Service-oriented architecture, ICT architecture,
Coordination.
1 Introduction
The Web is currently a preferred medium for distance learning and the learning
practice in this context is referred to as technology-enhanced learning or e-learning,
for short [8]. We claim that actual e-learning challenges are: (i) Reinforcing the links
between individual and organizational learning, and between learning and creativity -
it is challenging to embed learning, embracing knowledge, competency, and talent as
well as collaborative innovation and process workflows; (ii) Establishing and
sustaining interdisciplinary networks on emerging trends; (iii) Allowing context-
awareness and real-time adaptability in learning activities.
These challenges seem hard to resolve when taking into account the current state of
the art in e-learning that rarely reaches much farther than the distribution of .ppt and
Shishkov B. and van Sinderen M.
Service-Oriented Coordination Platform for Technology-Enhanced Learning.
DOI: 10.5220/0004463000300047
In Proceedings of the 3rd International Workshop on Enterprise Systems and Technology (I-WEST 2009), pages 30-47
ISBN: 978-989-674-015-3
Copyright
c
2009 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
.pdf files (even sophisticated environments that support learning, such as Blackboard
[2,3] are argued to be mainly content-driven and thus insufficiently powerful in terms
of collaborativeness, knowledge co-creation, and context-awareness). We claim that
this is partially due to the lack of instrumentation to adequately address the
coordination-related needs associated with a learning process.
Coordinating learning processes is currently difficult, not only because multiple
stakeholders are involved (such as students, teachers, administrative staff, technical
staff), but also because these processes are driven by sophisticated rules (such as rules
on how to provide learning material, rules on how to assess students’ progress, rules
on how to share educational responsibilities). This is one of the reasons for the slow
progress in e-learning. Consequently, there is a clear demand for technological
facilitation of the coordination of learning processes.
In this work, we suggest some solution directions that are based on SOA - Service-
Oriented Architecture [1,13,20,21]. In particular, we propose a coordination service
pattern consistent with SOA and based on requirements that follow from an analysis
of both learning processes and potentially useful support technologies. We present the
service pattern considering both functional and non-functional issues, and we address
policy enforcement as well. Finally, we complement our proposed architecture-level
solution directions with an example. The example illustrates our ideas and is also used
to identify: (i) a short list of educational IT services; (ii) related non-functional
concerns; they will be considered in future work.
The outline of the remaining of this paper is as follows: In Section 2, we introduce
the Service-Oriented Architecture – SOA and we outline some of its strengths that are
relevant to e-learning. In Section 3, we analyze the complex learning process and
identify SOA-relevant requirements for an advanced ICT coordination system. Then,
in Section 4 we propose architecture-level solution directions that relate to some of
the identified requirements and are partially illustrated in Section 5 by the means of
an example. Finally, in Section 6, we analyze related work and present our
conclusions.
2 SOA for e-Learning
In this section, we briefly recall the principles that underlie service-oriented
approaches and subsequently discuss the potential beneficial implications of these
principles for the e-learning domain.
SOA Principles. The main objective of SOA is to be able to create new applications
from existing services, independently of who provides these services, where they are
provided, and how they are implemented. Although this ideal is hard to realize to a
full extent given practical business requirements, SOA provides a sound architectural
foundation [6] and supportive technologies are currently available to test service-
oriented approaches in practice [11].
A 'service' is a self-standing piece of functionality offered to the outside world. To
access this functionality, a service user interacts with the service interface, using
messages and a basic message exchange pattern defined by the interface. The service
interface is independent from the service implementation. For example, a legacy
31
application may expose its functionality through a service, thus allowing external use
without disruptive measures for internal users. The technologies supporting these
principles are WSDL, for the definition of web service interfaces, and SOAP, for the
exchange of messages based on standard Internet protocols.
Service providers can store information on their services, called service
descriptions, in public (or closed community) repositories, enabling users to discover
services that fulfill their requirements. These repositories can be organized in much
the same way as telephone directories, with white pages, yellow pages and green
pages, to facilitate different search strategies. For example, a repository's 'green pages'
provide information on how to interact with a service by giving a pointer to the
corresponding interface (WSDL) definition. The functionality of a repository for
storing and organizing service information and enabling discovery of services can be
provided as yet another service. The technology supporting this is UDDI.
Often real-life collaborations require coordination between partners which cannot
be enforced by the simple message exchange patterns defined by a service interface.
Therefore, service behaviors have to be defined that capture required orderings and
dependencies. There are two perspectives on service behavior. The first perspective,
called choreography, is concerned with the exchange of messages between two or
more partner processes. The second perspective, or orchestration, considers a message
exchange from the point of view of one partner process. A technology for defining
choreographies is WS-CDL. Frameworks for specific types of coordination are also
available, such as WS-Transaction. Orchestrations can be defined with WS-BPEL.
Choreography is essentially a public process or protocol that tells a partner how to
behave in order to take part in a collaboration. On the other hand, an orchestration is a
private process which specifies interactions with external services. An orchestration
can therefore be used to define a composition of services. The result of this
composition can again be exposed as a service. This composite service has a richer
functionality or targets a more specialized community of users compared to the
composed, or atomic, services. Since composite services may again be used in
compositions, a hierarchical organization and composition is possible. Advanced
discovery and composition algorithms allow rapid service creation and even dynamic
service composition at run time. In the latter case, a service request is resolved by a
suitable service composition (in case no match exists between the request and an
individual service) based on the services found in the services registry. OWL-WS is a
technology that allows the composition of services in a workflow using semantic
information.
For an overview structure of SOA-related standards, we like to refer the reader to
Figure 4 in [20].
Benefits for e-Learning. Being able to abstract from technological details and create
reusable components (i.e., services) brings several potential benefits to enterprises,
including those involved in education. Here, we will focus on the benefits from the e-
learning perspective.
First of all, SOA allows institutions to continue to use legacy applications in new
systems. This is the case since services are described independently from any
implementation technology, and are accessed through standard WSDL interfaces. It is
important to realize the relevance of this principle for the e-learning domain.
Educational institutions must integrate processes and provide services for many
32
different people: those involved in the primary process, such as teachers, students, and
assistants; those involved in providing educational resources, such as librarians; those
involved in administrative support; those involved in planning, designing and
maintaining educational material, systems, facilities and so on. Because of the varying
needs of these people, educational institutions typically use various IT systems,
legacy as well as new, which have to share data in order to support the enterprise
processes.
SOA allows to mix and match legacy applications exposed as services with new
application components to form composite applications. Moreover, 3rd party
applications may be used as well, provided they are exposed as services. In this way,
an e-learning system may be assembled by choosing required functionalities from the
Web, if not available in-house, instead of building them from scratch or buying
packages that have to be installed and integrated in the existing environment. Again,
this can be of great benefit to educational institutions, since each of them has
developed components (course material, course delivery systems, searchable
repositories of learning objects and so on) which are potentially useful to other
institutions.
Hence, SOA brings greater flexibility to (re-)use applications and to develop new
applications and systems. Development may be much faster, and more cost-effective,
also because services of 3rd party applications can be incorporated in new systems.
Maintenance may also be easier, as implementations of services can be replaced
without affecting functionality, and functionality may be changed or extended
according to new requirements by changing or extending the composition of services.
In addition, focus can be on domain aspects such as learning, processes and
experience, instead of on technology.
The modular approach supported by SOA also allows educational institutions to
offer diversity and apply different pedagogical methods according to purpose,
audience and circumstances. Furthermore, e-learning may become more learner-
centric and personalized, with high learner-empowerment and personalized learning
pathways, thanks to the greater flexibility offered by SOA. Two parallel technological
developments related to SOA are relevant here: dynamic service composition and
context-aware services.
Dynamic service composition refers to the possibility to have runtime discovery,
selection and composition of services based on a user request, followed by the
delivery of the resulting composite service to the user who submitted the request. This
technology is still in an early stage, based on syntactic matching of input and output
messages of atomic (request-response) services. However, it is expected that advances
in this area will allow semantic discovery and matching of services with more
complex behaviors. A future scenario could be that a learner formulates requirements
in terms of learning objectives, topics and timing, and that a service discovery and
composition engine subsequently proposes possible services bundles which can be
scheduled for delivery.
Context-aware services concern applications that take the context of the user into
account when delivering their services to that user. User context comprises a range of
dynamic properties that reveal something about the person who is also the potential
user of a service [15]. Examples are the geographical location, local weather or
environmental conditions (temperature, humidity, pollution, toxic gases), physical
activity (sleeping, exercising), and bodily position (standing, sitting, lying). User
33
context data is unobtrusively gathered by sensors, and converted into useful context
information for the application through a process of aggregation and inference. The
application then adapts its service based on the context information, which is
correlated to perceived personal needs of the user. Context-aware technologies have
been developed in several research projects, but design methods that can
systematically derive useful context-aware services and scalable supportive
mechanisms are still lacking. Nonetheless, the relevance of context-awareness for e-
learning is not hard to imagine. A future scenario could be that the e-learning system
uses context (as well as stored preferences and historical data) of individual learners
to adapts its services in order increase effectiveness and efficiency of learning.
3 Implications from the Perspective of Learning
A typical learning process is driven by the necessity of educating the student [10]. It
requires also considering the one helping students in acquiring knowledge, namely the
teacher. Student and Teacher are hence two essential roles in any learning process.
Besides teaching and learning, some other activities to be taken into account,
especially in modern society, are: (i) student selection (examiners usually conduct an
entrance selection); (ii) controlling the learning process (administrators usually
execute control over teachers on the learning content; it is necessary clarifying that by
administrators we do not mean the administrative staff responsible for gathering and
processing some administrative information but those who control the courses with
respect to fitness in the overall educational program). We claim that a student-teacher-
examiner-administrator model can be considered as a valid although simplified model
of any learning process (the model is in fact simplified because we ignore, for the
sake of brevity, some issues including: a) another responsibility of examiners, namely
to evaluate students (through exams); b) another responsibility of teachers, namely to
specify the prerequisites for their courses and also the entrance criteria for the exam
(e.g. some practical assignment may have to be completed and approved before
entrance to an examination is allowed) while checking such prerequisites and criteria
is usually responsibility of administrators). We thus consider Examiner and
Administrator as two other essential roles in a typical learning process. In order to
identify requirements, we hence need to structure this as an initial step in describing
and analyzing the learning process in general.
Figure 1 shows the student-teacher-examiner-administrator model using a
diagrammatic technique derived from DEMO [5,18,19]. The identified entities
(reflecting corresponding roles) are presented in named boxes – these are Student (S),
Teacher (T), Examiner (E), and Administrator (A), while the small grey boxes, one at
an end of each connection, indicate the executor role of the connected entities. The
connections indicate the need for interactions between entities, in order to fulfill the
goal of educating; with each connection, we associate a single interaction, i1i3, as
follows: S-E (i1), S-T (i2), T-A (i3). As for the delimitation, S is positioned in the
environment of the education systemES, and E, T, and A together form the ES
system. Through i1
and i2, ES is related to its environment (represented by S).
34
i2
ES
i3
T
i1
E
A
S
Fig. 1. A simplified business entity model for an education system.
In order to be part of the learning process, a student would have had fulfilled the
entrance criteria, by passing some kind of entrance exam (i1 represents this with the
student in an executor role since the student has to deliver). Once the student is in a
position to participate in a learning process, a teacher is to deliver some kind of
learning service (i2) however only under the condition that this has been approved by
the controlling administration (i3).
This essential business model needs to be fulfilled by a realization no matter if it is
technology-driven or not. Since we are mainly interested in service-oriented IT
solutions, we analyze further the possible reflection of the model in that direction (it is
to be stated nevertheless that much of the following concerns at the same time the
business/institutional level). Further, we take an idealistic view, assuming that the
possibility to transfer credits among some institutions is acceptable in general – said
otherwise, a Student from University A can follow a course from University B and
use the result for credits at University A. We make this assumption because we
believe that the current globalization of education would lead to this. It might be even
possible (in the near future) for students from universities which are not very
prestigious, to attend courses in more prestigious universities. If this is the case
nevertheless, such ‘external’ students would have to follow special ‘versions’ of these
courses, adequate to their level and giving them less credit than to the ‘local’ students.
As for the gap between what we want and what is available, we have mostly an
‘institutional’ gap and a coordination gap. This is because currently, sufficient
technology exists, in our opinion, whose use is restricted however by university
regulations, national regulations, and other regulations, and also by the lack of all-
encompassing coordination mechanisms. Our proposed solution directions (that
concern an open service platform) are not supposed to overcome the ‘institutional’
gap, being only directed to the coordination issue – this is considered to be the added
value of what we propose in the current paper. It is to be mentioned as well that we do
not consider a university as an isolated entity – we consider universities as global
collaborative players, such that everybody can produce and consume global
educational services, driven nevertheless by some underlying rules. We can therefore
‘draw’ on the basis of this initial information (presented above), a high-level view on
what such a platform is to be:
- S-T SEARCH (ES should facilitate students in finding the most appropriate
teachers for their needs and vice versa; we would however consider students
to be in general foremost interested in the content (topic, learning material,
course set-up) and only then look for the best or most suitable teacher);
- S-T MATCH-MAKING (ES should adequately connect a student(teacher) only
to those teachers(students) who match properly for collaboration, which
35
includes for example matching students’ demands and teachers’
qualifications);
- S-E EXAMINE (ES should facilitate students in their finding the appropriate
entrance exams and go for on-line selection with regard to the course(s) they
would like to enroll in);
- A-T REGULATE (ES should support administrators to regulate teachers’
work, by enforcing some compulsory rules through the platform);
- S-T RANKING (ES should help monitoring teachers’ qualification,
contribution and reputation, and storing such information for the purpose of
ranking teachers);
- T-T CO-CREATION (ES should facilitate teachers in their co-creating
courses, supported by course templates, collaboration tools as well as by
wizards).
Based on the above analysis and motivated proposal, we firstly define some
GENERAL REQUIREMENTS (demands) that are relevant to our suggested platform:
(i) possibility of easy and flexible use minimum burdened by the underlying
technology; (ii) process alignment (it is crucial that all ES-related processes are
appropriately aligned and synchronized so that adequate coordination can take place);
(iii) hierarchy of complex rules underlying the platform as a way to enforce the
desired functionality guaranteeing that all users will be properly served.
Taking these high-level demands that relate to the technological perspective, we
combine them with the domain details, considered in this section, concluding that the
platform must be capable of enabling and facilitating an innovative methodology on
how to conduct education. From this objective, some REQUIREMENTS
ELABORATION can be derived upfront:
- it should be possible to mix and match learning modules offered by different
organizations on geographically distributed nodes using diverse technologies;
- the mixing and matching is typically prepared and constrained by a program, by
defining learning profiles, learning paths and learning policies that are generally
useful with regard to a goal;
- the mixing and matching should be completed by the student, such that (s)he can
tailor the learning content, method and plan according to personal needs and
preferences given the constraints imposed by a learning program;
- it should be easy to add, remove and update learning modules so as to keep pace
with changes in knowledge/skill demands and to profit from the availability of new or
improved learning modules;
- it should be possible for students to transfer their experience and expertise to
other students by contributing to or co-creating the content of certain learning
modules;
- the delivery of learning content should be automatically adaptable to personal
conditions, such as availability, place and device characteristics, using context sensors
and context reasoning;
- teachers should have the possibility to be informed about the learning modules
that are successfully completed by their students so as to compare realized and
required knowledge/skill levels relevant for the considered education goals;
- students should have the possibility of knowing their knowledge/skill level (based
on learning modules successfully completed) and as well how to improve it.
36
We discuss in the following section solution directions that relate to some of the
requirements already defined.
4 Solution Directions
Elaborating further on how IT services can usefully support education goals, we will
consider in this section: (i) the composition of IT services for education; (ii) related
cross-cutting concerns; (iii) resolution of conflicting business processes.
Composition of IT Services for Education. The demands mentioned in the previous
section provide a starting point to create education services. We need to take into
account also the following:
- the education services may be supported in terms of IT services which in turn are
provided by generic education service components;
- business processes need to be analyzed in order to adequately determine
orchestration (coordination) with regard to the use of IT services.
We illustrate this view in Figure 2:
1 2
3
4
business
p
rocess
IT
service A
education
service
generic education
service components
IT
service B
IT
service C
IT
service D
implemented by
Fig. 2. Composition of IT services for education.
As shown in the figure, a business process implements an education service, as a
way to underlie the desired functionality that corresponds to a customer (end-user)
need. The business process needs to be analyzed in order to define adequately a data
and control flow in which the supporting IT services are called in the right order and
with the right parameters. Thus the IT services point to service components that are in
general not especially developed for the application under consideration (for example,
education resource manager, examiner, regulator), although they are specific for the
education domain. They need to be configured (instantiated with the proper parameter
values) in order to lead to the realization of IT services that relate to business process
actions.
It is as well seen that (i) the upper part of the figure is about business activities
unrestricted by technology (the education service is implemented by a business
process that in turn consists of actions performed by humans (or at least controlled by
humans)); (ii) the lower part of the figure concerns IT services which are realized by
ICT components. We hence should address the ‘IT level’ with more attention because
much at the ‘business level’ is driven by organizational and/or societal rules, human
relations, intuitive human decisions, and so on, which need to be analyzed, simplified
and reflected in the ‘intelligence’ of the IT system. The coordination (orchestration)
of business actions is pushed by human intelligence; with regard to the coordination
37
of IT services nevertheless, we need to actually make decisions about it at design
time. In considering technology-enhanced learning, we propose a single point of
coordination because of the following reasons: (i) unlike in solving supply-chain-
related mediation, for example, in supporting learning, we would not often have the
case of hundreds of users being served simultaneously and therefore sophisticated
coordination would add little value; (ii) mixing and matching learning modules (as
required – consider Section 3) adequately would usually demand one point of
coordination (otherwise, too complex facilities for prioritization would have to be
considered); (iii) the domain of education is dynamic in a sense that often new
rules/regulations appear, which means that the system design would have to be easily
updateable, and with a single point of coordination updates would obviously be easier
than in cases of complex coordination.
In the remaining of this paper, by service we mean only IT service.
Hence we introduce a service coordinator which in SOA terms should be a service
that can be invoked to coordinate other services (we label such a service coordination
service). In taking care of this nevertheless, the coordination service would deal
inevitably with exchange of information concerning many issues, and this information
would need hence to be stored and managed. We introduce thus a service that can
store information and allow other services to find information (we label such a
service information service). Such services (coordination-related and information-
related) are claimed to be central for approaching problems that concern technology-
enhanced learning in a service-oriented way. Figure 3 gives a general view on this.
The figure depicts 5 layers that are widely considered in discussing service-
oriented reference architectures – ICT components can operate on top of an
operational system, in their delivering services which in turn are developed for the
purpose of supporting particular goals concerning some business processes, which
goals appear with regard to needs of customers [7]. The layer that is explicitly
considered in this work is the ‘Services’ layer and we thus elaborate there our
proposed solution directions. As it can be seen from the figure, the coordination
service and the information service are of crucial importance since they support the
deliveries of all other services – the coordination service orchestrates the overall work
of the system, invoking other services at the right moment and offering them also the
right input; as for the relation between the coordination service and the information
service, it is not trivial since the coordination service would need support from the
information service on most of the service invokations, hence this complex relation is
indicated by the dashed line between the coordination service and the information
service. What is also shown in Figure 3 is that all other services operate through the
mediation of the coordination service.
In the following section, we will identify through an illustrative example, a short
list of IT services that have relevance to technology-enhanced learning. It should be
noted that all that has been discussed so far with regard to IT services concerns the
functional perspective and in order to be more exhaustive in presenting our proposal,
we consider briefly in the below paragraphs crosscutting non-functional concerns.
38
operational system
components
business processes
customers
services
coordination service
information service
Service 1
Service n
Service 2
Fig. 3. A service-oriented solution direction for technology-enhanced learning.
Crosscutting Concerns. The architectural view already presented in the current
section focuses on the desired primary functionality. Nevertheless, it appears that
some concerns can not be easily localized and specified in individual architectural
components, as researched by [22]. Similar to practice in aspect-oriented software
development, we call such concerns crosscutting concerns [23,4]. Since crosscutting
concerns are inherent, it is claimed that these cannot be undone simply by redefining
the software architecture using conventional architectural abstractions. Explicit
mechanisms are thus needed to identify, specify and evaluate such concerns at the
architecture level. For the sake of brevity, we are not going to discuss this in further
detail and will limit ourselves to only mentioning several such crosscutting concerns,
especially ones that we claim to have relevance to the service-oriented IT support to
technology-enhanced learning, as considered in the current paper: synchronization,
distribution, security, privacy, and logging (illustrated in Figure 4):
CROSSCUTTING
CONCERNS
synchronization
distribution
security
privacy
logging
Fig. 4. Identified crosscutting concerns.
39
Although they are not specific to any particular process/component (with respect to
the delivery of IT services for supporting technology-enhanced learning), these
crosscutting concerns are still claimed to have huge importance for the adequacy of
the platform, because:
- all processes that concern students and teachers are to be synchronized among
each other and with respect to the overall program so that it is avoided for
example that an exam is appointed for a date on which the examiner has also
other obligations [synchronization];
- it is essential to offer support for distribution with regard to the need for
courseware co-creation by teachers who are in different locations
[distribution];
- high levels of security are necessary for adequately controlling numerous
copyright-protected resources and personal data [security];
- privacy-sensitivity is essential in guaranteeing that for example, only the
education-related data concerning students will be accessible to their teachers
[privacy];
- it is also necessary keeping track of events that may later play a role in
presenting proof of what actually happened [logging].
We have presented in both functional perspective and non-functional perspective
our proposed views with respect to SOA-related supporting of activities that concern
technology enhanced learning, and we will discuss in the remaining paragraphs of this
section some complementary policy-related issues.
Policies. As already mentioned in this section, some corresponding business
processes need to be analyzed in order to define adequately a data and control flow in
which the supporting IT services are called in the right order and with the right
parameters; this is needed in order to properly specify the coordination service which
is responsible for invoking other services.
Hence, we need to consider policies in specifying the coordination service. This
would often point a (standard) procedure that may be defined by rules (e.g., a service
at a library often points to the following business process: Student makes selection of
books, Librarian announces the maximum possible period of holding (each of) the
books, Student takes the books). There could nevertheless be conflicting actions (in a
business process) or even conflicting business processes [14]: let’s assume, for
example, that the education service ‘Assessment’ is implemented by a sequence of
activities as follows: Examination, Evaluation, Announcement (the teacher should
conduct the exam first, then make a review and put mark, and finally – announce the
mark to the student); it may be that in cases of external teachers examining, there is a
requirement for an approval (by a local teacher) of the evaluation output. We are thus
facing a conflict that concerns both semantics and pragmatics [16].
Figure 5 illustrates this:
40
examination evaluation announcement
examination evaluation announcementapproval
Fig. 5. A semantic conflict concerning an education service.
Based on previous work [17], we claim that Organizational Semiotics (OS) in
general and the Norm Analysis Method – NAM [9], in particular can be of use in
resolving such semantic conflicts and enforcing policies, taking into account not only
the rules-related strengths of NAM but also its sound semantics-related OS theoretical
roots.
Norms, which include formal and informal rules and regulations, define the
dynamic conditions of the pattern of behavior existing in a community and govern
how its members (agents) behave, think, make judgments and perceive the world.
Norms are developed through practical experiences of agents in a community, and
in turn have functions of directing, coordinating and controlling their actions within
the community. When modeling agents and their actions, which may reveal the
repertoire of available behaviors of agents, norms will supply rationale for actions.
Norms will also provide guidance for members to determine whether certain patterns
of behavior are legal or acceptable within a given context. An individual member in
the community, having learned the norms, will be able to use the knowledge to guide
his or her actions, though he or she may decide to take either a norm-conforming or a
norm-breaking action. When the norms of an organization are learned, it will be
possible for one to expect and predict behavior and to collaborate with others in
performing coordinated actions. Once the norms are understood, captured and
represented in, for example, the form of deontic logic, it will serve as a basis for
programming intelligent agents to perform many regular activities [9].
The long established classification of norms distinguishes between perceptual,
evaluative, cognitive and behavioral norms; each governing human behavior from
different aspects. However, in business process modeling, most rules and regulations
fall into the category of behavioral norms. These norms prescribe what people must,
may, and must not do, which are equivalent to three deontic operators “of obligation”,
“of permission”, and “of prohibition”. Hence, the following format is considered
suitable for specification of behavioral norms:
whenever <condition>
if <state>
then <agent>
is <deontic operator>
to <action>
The condition describes a matching situation where the norm is to be applied, and
sometimes further specified with a state-clause (this clause is optional). The actor-
41
clause specifies the responsible actor for the action. The actor can be a staff member,
or a customer, or a computer system if the right of decision-making is delegated to it.
As for the next clause, it quantifies a deontic state and usually expresses in one of the
three operators - permitted, forbidden and obliged. For the next clause, it defines the
consequence of the norm. The consequence possibly leads to an action or to the
generation of information for others to act [9].
Norms can be specified in both a natural language and a formal language. For
example, adopting the format given above for specification of behavioral norms, a
credit card company may state norms governing interest charges as:
whenever an amount of outstanding credit
if more than 25 days after posting
then the card holder
is obliged
to pay the interest.
We hence claim that underlying (hierarchies of) norms can play a useful role in
enforcing policies with regard to the coordination service, as depicted in Figure 6,
where the importance of enforcing policies in each service invokation is explicitly
shown as well as our proposed use of a hierarchy of semiotic norms for that goal (a
possible norm hierarchy is illustrated abstractly in the figure); the dashed line between
the coordination service and the norms indicates the need for the service to be aware
of the norms which it should enforce in invoking services.
coordination
service
Service 1
Service n
Service 2
hierarchy of norms
policy enforcement
Fig. 6. Norm-driven policy enforcement.
After having introduced our proposed solution directions with regard to a service-
oriented coordination platform for education, we will present in the following section
partial illustration concerning nevertheless only some business-processes-related
issues, and in particular the reflection of business processes in application
functionalities as a bridge between the education services and the IT services
supporting them.
42
5 Illustrating Example
We start from the simplified business model that is depicted in Figure 1 in order to
illustrate partially how IT services can be methodologically reflected in a model,
which reflection is driven by analyses concerning not only the corresponding business
processes but also the demanded ICT support. We in particular derive the Education
Mediator (EM) on the basis of the details that have been presented in Section 3. We
would expect hence that an EM would support customers in a number of ways, in an
e-learning context. By ‘customers’, we mean the users of EM’s services; those could
be students and teachers (in the simplest case). Furthermore, we address (for the sake
of brevity) only EM’s advice provisioning service: a customer can receive from EM
advice which of the Student/Teacher entities (registered in the system) best satisfy a
need (for example, which is the best teacher with respect to a particular student
demand). To receive advice from EM, the customer approaches EM’s ADVISOR (an
entity inside EM, which is responsible for handling the advice provisioning). It should
be nevertheless noted that the Advisor may be shielded from the customer by the EM
and in such a case the customer would be ‘talking’ to the EM and the EM would in
turn route requests to (and results from) the Advisor. Approaching the Advisor, the
customer should specify a request: course type (e.g. lecturing course or experimental
course), preferences (e.g. closest to a particular subject), and so on. Based on this (and
acting ‘through’ the Match-maker, to be introduced further on in this paragraph),
EM’s REQUEST HANDLER (an entity inside the EM which processes requests)
generates a standardized request specification, appropriately synthesizing some of the
information provided by the customer. This is delivered then to EMMATCH-
MAKER (an entity inside EM, which is responsible for finding a match using the
standardized request and considering what is currently available); the Match-maker
realizes matches driven by particular criteria, chosen by the customer (and
represented in the standardized request), for instance: a preference for a teacher from
a particular country or institution or the earliest available teacher. In order to realize a
criterion-driven match, the Match-maker applies relevant rules and procedures,
nevertheless needing input from EM’s DATA SEARCHER (an entity inside EM that is
responsible for searching). The Data searcher searches through the information
concerning the available (Student/Teacher) entities and also applies procedures to it.
This hence supports the identification of candidate matches relevant to the particular
customer’s request. The Match-maker applies its rules and procedures to realize a
final match, passing this information to the EM’s Advisor.
Considering the above-presented briefing, a business entity model is built (Figure
7), with the same notations as we have already used in building the model that is
presented in Figure 1.
i3
i4
i1
EM
i2
C
A
MM
R
D
Fig. 7. Business entity model for the EM case.
43
The identified entities are presented in named boxes as in the previous model –
these are Customer (C), Advisor (A), Match-maker (MM), Request handler (R), and
Data searcher (D). Interactions i1 – i4 are identified as follows: between C and A (i1),
between A and MM (i2), between MM and R (i3) and between MM and D (i4). As for
the delimitation, C is positioned in the environment of the education mediation system
EM, and A, MM, R and D together form the EM system.
We model then interactions using the notations of UML Activity Diagram [16]: i3
and i4 are to be progressing in parallel and only after they have been exhausted (the
standardized requests and candidate matches have been delivered) the match-making
can be done (i2) followed by the advice (i1) – this is illustrated in Figure 8 (upper
part). This is the business process level, as labeled in the figure, and it is assumed that
human-driven roles (and responsibilities) stay behind each of the interactions and as it
is about human activities, much is driven by complex organizational (and societal)
norms, much is actually done using best practices, and much is done in an intuitive
way. IT services nevertheless require defining everything explicitly. That’s why the
IT services that correspond to the business-process-level interactions, are considered
together with other related issues, as it is shown in Figure 8 (lower part), depicting the
IT service level, as labeled in the figure.
Service 4
i4
i3
i2 i1
search
algorithms
security
engine
access
manager
repository analysis
engine
translation
tool
Service 3 Service 2 Service 1
business process level IT service level
Fig. 8. Service derivation for the EM case.
As it is seen from the figure, searching requires search algorithms, request
processing requires an adequate supportive security engine and access control
facilities, match-making needs repositories with candidate matches and match criteria,
the delivery of an advice requires an analysis engine and sometimes, a translate
facility, just to name a few.
We need to extend further this model, particularly with respect to ‘IT Services
level’, by considering our adopted service pattern that is depicted in Figure 3, which
pattern is driven, as it has been discussed already, by a coordination service,
responsible for orchestration. The EM service model is presented in Figure 9:
44
Service 4
search
algorithms
security
engine
access
manager
repository analysis
engine
translation
tool
Service 3 Service 2 Service 1
coordination service
information service
Fig. 9. Service model for the EM case.
As it is suggested by the figure, a coordination service (supported by an
information service) orchestrates the work of the other services, namely Service 1,
Service 2, Service 3, and Service 4, in a way that has been discussed in Section 4.
Taking into account the case information and the considered domain, we label these 4
services in the following way:
- Service 1: Educational Mediation Service;
- Service 2: Educational Broker Service;
- Service 3: Educational User Agent Service;
- Service 4: Educational Resource Discovery Service.
We claim hence that the service pattern presented in Figure 9 as well as this short
list of services (which can be extended) are useful for further related research in the
area of technology-enhanced learning.
With respect to crosscutting concerns, the already identified ones are valid for this
case, taking into account the discussion that has been already presented in Section 4:
- Crosscutting concern 1: Synchronization;
- Crosscutting concern 2: Distribution;
- Crosscutting concern 3: Security;
- Crosscutting concern 4: Privacy;
- Crosscutting concern 5: Logging.
This is as well a useful short list of crosscutting concerns (which can be extended),
useful for further research in the area of technology-enhanced learning.
We will not consider in this example policy enforcement, for the sake of brevity.
6 Related Work and Conclusions
In this paper, we have presented solution directions that concern technology-enhanced
learning and in particular the adoption of a service-oriented architecture for
accomplishing better coordination and ease of application and use.
The current developments that concern technology-enhanced-learning-related
systems point in several directions, namely: (i) Virtualization of learning; (ii)
Adoption of Service-Oriented Architecture for enterprise systems in Education; (iii)
Tooling.
45
With regard to virtualization, the project LiLa [10] addresses the challenge of
making lab experiments more widely accessible, through automation and control from
distance via Internet, driven by advanced access control mechanisms. With regard to
service-orientation and related solutions, IMS Global Learning Consortium [8] has
proposed an architecture for education-related enterprise systems, inspired by some of
the latest SOA-related achievements. With regard to tooling, tools such as Moodle
[12] are currently undergoing development that nevertheless strongly depends on the
envisioned upcoming advances in the direction of service-orientation.
Distinctive features of the proposed solution directions are: (i) Methodological
derivation of IT services, based on business analysis and modeling; (ii) Consideration
of (service-oriented) coordination as a way for orchestrating and facilitating the work
of an e-learning system; (iii) Envisioning underlying infrastructures for the next
generation of e-learning systems.
To further this research, we plan to achieve a holistic perspective on technology-
enhanced learning, in which we will consider the aspects mentioned above.
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