Amar Balla and Nabila Bousbia
Laboratoire LMCS, Ecole Nationale Supérieure d'Informatique, BP 68M, Oued-Smar, Algiers, Algeria
Keywords: Learning environment, Adaptive Learning, Generic Course, Knowledge Unit.
Abstract: This work is part of a large research project aiming at implementing of a distant learning platform, based on
the Web. The goal of this article is to present the methodology adopted in the architecture of this system.
Our architecture aims at offering a flexibility of options input, in order to be independent and adaptive with
respect to all education systems. By the adoption of LTSA standards and the use of the 3 – tier architecture
of the Web, our system ensures a maximum of interoperability with the other platforms. While following
the nature even of the process of education, we adopted a hierarchical and generic structure for the platform
The pedagogical revolution and the fast
development of the distant learning, often
concentrated on courses production, and the
definition of this production rules (Alg, 2000). Other
research works are interested in the interoperability
of the diffusion platforms (Bousbia, 2007).
Most of the distant learning platforms are
developed around specific topics, of an owned
pedagogical method for the application editor, and
of an education system suitable for the area of
diffusion of the platform. An education system
represents the whole of coherent services given by a
distant learning platform (Brusilovsky, 2006). Thus,
such products are intended for a limited applying
domains and target population. That poses the
problem of applying to geographically distributed
populations, having generally different educational
Having benefited from the technological
development, the majority of the distant learning
platforms, in the trade and in academic world,
adopted the Web for their development. They insure
thus the criterion of mobility of the training actors
(learner, teacher, trainer, administrator), since those
actors needs to have just one browser and the
Internet to follow their distant activity.
However, and in terms of architecture, these
platforms respect rarely the standards dealing with
the course structure levels and the teaching
To implement a distant learning platform with a
broad diffusion, within various teaching
frameworks, it is important to focus on some vital
aspects. The system structure must be flexible and
self-adapting regarding the training environment. It
must use the specific vocabulary – communication
language - to the learning actors, in their particular
context. It must also apply to various education
systems. The standards adoption like (LTSA, 2000)
and their extension will be able to guarantee a higher
interoperability between different platforms.
In this paper, we first focus our work on the
identification of the architecture parameters, which
characterize a distant learning platform
(Brusilovsky, 2006). Theses parameters will allow
using the platform by a broad spectrum of actors,
with large geography and cultural distribution. We
then develop, the Taalim system architecture, which
aims to setup a virtual university.
The targets of our system are the basic and the
continuous training. These systems try to face the
needs for learning, according to users educational
contexts (Balla, 2007).
Several research works developed original
aspects of Taalim platform (Balla, 2009a)(Bousbia,
2007), such as asynchronous mode training, the co-
operation and the adaptability of courses to learners.
This paper focuses on the architecture of this
Balla A. and Bousbia N..
DOI: 10.5220/0003332002310236
In Proceedings of the 3rd International Conference on Computer Supported Education (CSEDU-2011), pages 231-236
ISBN: 978-989-8425-49-2
2011 SCITEPRESS (Science and Technology Publications, Lda.)
platform. We will use elearning word instead of
“distant learning” term.
Most of the elearning platforms integrate the
asynchronous mode of training. Thus they bring to
learners, an entrance without space-time constraints.
However, the users have to stick to a specific
methodology owned by the platform editor.
Whatever the originality and the interest of those
methodologies, learner will be disturbed. For
example, the lecture is part of a degree cursus
comprising other lectures taught in traditional mode
(presential) or on other platforms. Thus, the platform
diffusion may be highly limited by the lack of
adaptation to the pedagogical learning environment.
In the following we will introduce, fundamental
concepts of elearning platforms architecture, and
their conformity with the standards.
Characteristics of a Universal Architecture
Most of the emerging standards in elearning do not
treat the standardization of the methodological
approach of the teaching, nor the co-operation
aspects between the actors (learners, teachers,
trainers, administrators). However these elements
are fundamental in the act of training. They ensure
an open platform to be used in various contexts.
The standardization of on line learning faces the
combined need for a better economic profitability of
the investments in elearning and an improvement of
the pedagogy effectiveness of its products.
The motivations of implementation of platform
with broad diffusion were developed in work (Auf,
In this paper we will complete these and
reinforce them.
A training system must be able to propose its
services in a dynamic way. Learners should have
access to updated information, in a flexible and
effective way. The system must allow in a
distributed network, the activities of searching,
identifying to the platform, the access and the
delivery of the elearning contents and components.
It should ensure the independence of the users with
respect to the communication support (networks)
and its environment (Windows, Unix, etc).
Internet is used today as a standard, for
distributed data transport.
The actors of the elearning must have a large degree
of freedom, to reach the platform resources.
Indeed, the learner and the teacher need often, to
change work place, or environment (Linux,
Windows, etc). The use of the Web ensures this
mobility, since the used resources are preserved on
the server, and the user can reach them from any
Internet access point.
To increase the functionalities offered to the
users, most of the platforms put plug-in components
on the browser. Although these plug-in are
automatically downloaded at the first use, the excess
of them could obstruct the learner mobility.
It allows the use of contents and components
developed by other organizations on other platforms.
That supposes a high compatibility of the platforms
to the standards, at the structural level.
Main actual work of development deals with the
contents identification (metadata), the contents
structuring, the systems architecture and the
learner’s information. SCORM is the main model
for this purpose (Auf, 2002). This model integrates
the most important basic specifications.
The products available in the elearning trade are
often designed and developed according to an owner
approach. The processing under another system or
integration in a different training environment seems
to be almost impossible. In fact, certain platforms do
not support any education system. They propose
courses focused on a given matter, without
pedagogical objective (do not correspond to a
Interconnections between Education Systems
The access to a course, which is part of a cursus,
needs some pre-requires. Pre-requires can be a
diploma, a module, a chapter or even a section of
course. The difference in organization, in structures
and in terminology, in various education systems,
makes difficult to identify pre-requires between
different systems. Thus, it is important to manage
equivalences on several aspects, from the course to
the finest entities considered as prerequire (Balla,
This problem is rarely dealt with in the actual
It allows the adequate formulation of the contents
and the components. The adaptability acts on several
levels of the architecture.
It concerns the adaptation of the training process
to the learner profile. Thus, according to its
knowledge level and training progress, the system
CSEDU 2011 - 3rd International Conference on Computer Supported Education
should modify the studied matter itinerary (Balla,
2007) (Balla, 2009b).
Usually Learners have various objectives, and
are interconnected through diverse environments.
Thus, according to the pedagogical environment of
the learners, the platform must adapt its interfaces
with their educational system. For example, in the
Canadian system, the diploma is associated to units
of value, whereas the French system associates a
diploma to an academic year.
A flexible platform, must thus adapt itself to
users requirements and needs. Every learner should
have access to a lecture, which can be adapted to
his/her aptitudes, his/her training objectives and also
to the socio-cultural and computer environment
Users (learner and teachers) should be able to use
the system whatever their education system or their
training pedagogy.
It allows the contents and components to face the
technological developments without Re-engineering
nor Re-development. Durability can be developed in
terms of evolution of the educational system or its
extension. By structuring the architecture in an open
and evolutive way, and having the options
flexibility, we will offer to the elearning platform
large possibilities of durability.
Re- utilisability
It allows re-using the contents and components for
various needs, applications, products, contexts and
access modes.
This could be obtained by the distinction
between the structures of the platform and the
environment of training provided to the users.
At the current time, large efforts are made, to
ensure the reuse of teaching contents. That supposes
conformity to the standards. This is rarely the case
of the platforms with owner architecture.
Taalim, by its architecture, tries to respond a
broadest range of universality and generic criteria,
discussed before.
In order to make a training environment,
convivial and fully usable by learners, Taalim has
flexible and adjustable structures for various
education systems.
3.1 A Generic Structure
To give a maximum of abstraction towards the
specificity of the training environment and of
learner, we operate a significant remark. Indeed, any
education system fits well within a hierarchical
An education system is seen as a coherent
entirely structure, carrying out training objectives.
According to the place and the framework of use,
the objective can be a training course, a diploma, a
degree, etc. It is composed of training entities. The
entities can be one school year, one semester period,
a module, a unit of value, etc.
Each training entities are made up of training
elements, such as the lecture, the chapter, the
exercise, etc.
The decomposition can follow up to the smallest
level of granularity of training contents. At this level
we can find elementary training information, such as
a paragraph of text, an image, a slide, or other
Elements Medias (sounds, animation, etc). Thus,
independently of the adopted education system, and
the vocabulary used to name its components, we are
directed towards arborescence in the system
structuring (Balla, 2009a).
On this basis, we proposed an abstract structure
representing the training contents as a generic
arborescence. We named this structure, “Knowledge
Unit”. The generics enable us to represent a variable
number of hierarchical levels, and to have a
flexibility of representation, according to the
selected education system.
To realize this concept, we have to set up an
association between the specific terminology of each
education system, and the corresponding elements in
the arborescence. That will provide an interface that
permit Taalim to be adapted to various systems
The principles, which governed the development
of our system, are summarized by (Bousbia, 2007):
Independence: This principle defines the
needs and the interests of a generic model
independent from any education system and
any training method;
The Opening: allows the model to be
appropriate for any discipline and to deal
with the courses established in other systems;
Approach of Structuring: allows producing
adaptive generic courses as well as the level
of granularity of the training objects (To
separate the structure of the course from the
matter of training and To annotate the various
Knowledge Units);
Approach of Follow-up: it implements the
sequencing relationship of a course objects
according to training and educational
principles. It model learners training follow-
up in order to satisfy on line adaptability.
In our model, we propose an organization, which
facilitates at the same time the definition of the
training contents generic structures, and guarantees
the coherence of the contents with a good
Our generic model is valid for any educational
system. It tries to satisfy the guiding principles
specified further, with the training objectives.
Thus, Taalim treats in a simple way any
component of the educational system, whatever its
complexity, like a whole of Knowledge Units.
Knowledge Units are organized in arborescence
on several levels (Balla, 2009a). On the lowest level,
we find entities named Elementary Knowledge Unit
(KUe). KUe corresponds to the weakest and atomic
granularity. The sheets of this arborescence
correspond to the media elements (ME) of the
training contents (cf figure 1).
Each element of the arborescence in entities to be
taught is identified then with a node in the
Knowledge Unit.
Figure 1: A generic course structure.
Figure 2: Taalim Generic Model.
Figure 2 shows this association. Our internal
structure is thus, independent of the vocabulary used
in the real entities. A Knowledge Unit can be a
module, a unit or a course as shown by figure 2 of
the correspondences.
3.2 Independence Towards
the Education System
The educational models are developed according to
the socio-cultural constraints of the local and
regional environment.
Thus, the educational and training structures
change according to the learning context.
The existing platforms of elearning are
developed in two cases:
Some platforms stick to a specific education
system. They are not able to satisfy users of
different education systems.
Most of the commercial platforms do not
worry about the belonging to an education
system, nor to a common training approach
for all their courses. They focus on the
technical contents training, and do not pay
attention to a global framework (course,
module, etc).
These platforms are not suitable for users
adopting a different educational model. However we
should note that the contents are often comparable in
different education systems. The difference lies
mainly in the decomposition of the course elements
(module, chapter, paragraph, etc.), and especially in
the vocabulary used to name them.
By preventing these situations, it is possible to
encourage the actor (learners, author, and monitors)
to use more and more the elearning systems. This
will give to learners the flexibility to remain in their
education system, while having access to the
information produced by other systems.
It proves, that with judicious choices in terms of
the platform structuring, we can obtain a system,
which can adapt to the majority of training
organizations types.
This flexibility permits to the administrator to
establish a general parameter input of the platform,
according to the general choices. For example, he
can choose the French education system. Then he
defines as training objectives an engineers training
cycle allowing a diploma. For entities he chooses
modules, and for sub-entities he chooses courses.
The author actor can define the structure of his
training entities, by defining his decomposition, for
example, in sections, chapters, paragraphs, etc.
KU11 KU12 KUe21 KU22 KU23
SubChap. SubChap.
CSEDU 2011 - 3rd International Conference on Computer Supported Education
He then, interfaces the system by associating the
structures and the vocabulary used in the learners'
education system, with the components (Knowledge
Unit for example) of the platform structure.
To ensure these objectives of independence,
Taalim uses the concepts of Pedagogical objectives,
and Knowledge Units supported by the generics.
3.3 Software and Hardware
To make our choices, we adopted the principle of
The strategic choice is then the adoption of
Internet like support of exchanges between the
platform and the actor.
That automatically responds to all the criteria, for
user's environment. The client is thus, a browser to
access to Internet.
Learner’s access is done via internet (chat, Web
explorer, videoconference kits, etc).
Thus, learner is not constrained to remain
connected to the same PC or to the same operating
system, to follow his distant courses.
The client activity is limited to displaying
functions and to sending queries towards the server,
without local treatment. The results of its queries are
then displayed on his screen.
Now we must choose the web server, which
supports all the platform activity. Since the elearning
activity, requires lot of treatments, and uses database
to store all training materials, we chose an
architecture that gives good technological
performances. Thus, we base our platform on the 3 –
tier architecture (Bousbia, 2007).
In this architecture, the first tier is the client. The
second tier is an applications server (a web server).
This server has an engine for the treatment of the
queries emitted by the browser (for example an
engine of servlets), and returns the results. The
applications server transmits requests towards other
additional servers (DBMS for example) that
represent the third tier. They are codified in an open
source and portable language (Java for example).
They manage and treat access to database.
3.4 Implementation of Adaptive
The Taalim system having the objective to provide
an adaptive course, a need for a good structuring of
the course documents is obvious for a
comprehension of this structure by the system in
order to extract some information targeted to provide
a course adapted to each learner profile. Another
need is that to be able to handle these documents,
either to create others or only to modify them.
In the search for a solution to our needs, our
choice was made on XML (eXtensible Markup
Language) to describe the structure of the Taalim
course. Indeed the automatic generation of the
course as facilitated by the use of XML parsers likes
XT of James Clarck, Xalan of Apache, etc.
The adaptation of the course according to the
user profile is made possible using XSLT
(eXtensible Stylesheet Language Transformations).
It will first of all be necessary to adopt a structure
defining the relationship between the course and the
profile as in the case of Taalim.
XSLT can transform an XML document into
another XML document according to present
selection criteria (educational, localization, etc.).
Thus, a generic course, containing all the
possibilities, will be transformed into a specific
course thanks to an XSLT document which includes
specificities of the learner profile (figure 3). In fact,
the general transformation parameters contained in
the generic XSLT document are transformed using
the profile values.
As figure 3 shows it, once that our Taalim course
is well structured and written in accordance with the
DTD of the Taalim course, it is stored and
constitutes the generic course. It is starting from this
generic course that specific courses will be
generated with the need to satisfy the learner
pedagogical objectives.
Figure 3: Generation Implementation.
This phase breaks up into three sub-phases which are:
on the one hand the generation of the specific
XSLT (starting from a Generic XSLT)
according to the learner profile which will be
used as filter for;
GenericXML SpecificXSLT
the generation of specific XML course;
After the generation of specific XML course,
the following phase is that of the presentation
of the course to the learner. The use of style
sheet will make it possible to personalize the
presentation of the course according to
preferences of each learner. Its role will be to
format XML specific files in a posting format
(HTML, SMIL format, etc.) recognized by the
web browser (Bousbia, 2007).
3.5 Accordance with the Standards
In order to ensure independence and modularity,
Taalim architecture is conform to the LTSA
standards (LTSA, 2000). The main goal of LTSA is
to provide a framework to support interoperability
and portability (deployment in multi-platforms) of
the elearning systems. In this order Taalim supports
the description in an abstracted way, of the principal
components of the system architecture.
To provide multimedia elearning architecture,
based on the Web, Taalim is based on the integration
of standard and open tools such as XML, XSL,
DOM, Servlet and Java programming.
However lot of work has to be done in terms of
standardization. No standard was recognized
officially by the ISO, and in spite of significant
developments, several questions remain without
This article, after the identification of the specific
problems to the adaptability of remote teaching on
Internet, exposes the total knowledge inherent to the
production and the diffusion of adaptive courses on
the web. We consequently detailed the various
knowledge used in our system namely the generic
course and the element of the learner profile.
And finally we showed how all these concepts
are orchestrated to set up the adaptability in Taalim.
To validate this work, a prototype was installed and
tested to offer a High speed network course for
different pedagogical objectives and different levels.
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CSEDU 2011 - 3rd International Conference on Computer Supported Education