• Facet "Metadata LOM" allows the description of a
Learning Object by using Metadata (author, language,
level, location.......) this part is similar to Metadata
described in LOM norm[12]. But in order to satisfy our
needs , and to make the analysis easier, we have
established a set of vocabulary. A LOM description is
attached to each LO . This description is illustrated in
figure 5. The associated Metadata provides précis's and
well classifies information about each LO rendering the
ulterior researches more effective .
• Facet "Category" helps to classify the LOs in different
categories (introduction, example, definition,
illustration, exercise....) depending of their contents.
• Facet "multimedia brick" a LO is presented by
multimedia bricks which can be either an image, video,
sound, text, executable, an animation or simulation.
The two ontologies elaborated domain of application and
Learning object are bound by the following semantic relations:
• Has-for-object: This relationship links a concept X of
the domain ontology to one or more LOs. It allows
the learner (user) to access immediately to knowledge
in order to assimilate the concept.
• Treat: allows linking a LO to a concept of the
domain ontology.
1) The chapiter Web service : This service takes charge
of the construction of the chapter pedagogical activity ,
according to the entries that it receives from user
(learner).This service has as inputs the concept’s name chosen
by the user as well as characteristics of the user (preferences,
knowledge, etc.) and will have as output the personalized
chapter.
C : the names of concepts
UC: user characteristics
a. The functioning principle of this service: the domain ontology
concepts , index Learning Objects which enter in the chapter
construction (introduction, definition, illustration, example,
etc.). The fig.6 illustrates the principle.
Fig.6. Process of construction of the chapter pedagogical activity
• Selection: when the user of service has defined the
concept on which he wants to search LOs to build his
chapter, the service is going to verify if the
prerequisites of this concept are acquired by the user by
using the characteristics provided in entry and in case
prerequisites are not acquired, the service is going to
add to his selection, this concept and its
prerequisites.Each user must gradually learn the
concepts of the domain while starting with the concepts
related to his current level. There will be a process of
research LOs. The identification of LOs relevant to a
concept is based on the user(learner) model and domain
model knowledge. The proposed annotation Learning
Objects systematically connects LOs to their concepts.
The service builds a request to the LO base. This
returns the LO identifiers corresponding to the concept.
• Adaptation : The result of the previous step is a list of
objects found explicitly . This list is subject to another
module that compares the semantic usage of each LOs
in the list with a description of the preferences of the
learner. The operation of the filtering is to retain among
the LOs resulting to the selection step that the objects
that meet the criteria specified by the user.
• Organization: This step corresponds to the arrangement
(scheduling) of different LOs selected by the previous
step within documents.
2) the assessment Web service : This service supports the
administration of both online multiple-choice and true/false
tests. It employs assessment functionality in the delivery of
tests according to the entries which it receives from the user
(concepts, characteristics) , returns scoring after the user
finish the test and the time spent in the test for each user . It is
these results which allow to make the synthesis to know if the
considered concept is acquired.
3) The simulator Web service : this functionality
proposes to the user (learner) experimental activities,
simulations for better apprehending a phenomenon or
functioning according to the entries which it receives from the
user (concepts, characteristics ).
4) The exercise Web service : provides the exercise
pedagogical activity according to the entries which it receives
from the user (concepts, characteristics ).
To facilitate the discovery of the e-learning Web services
(e-learning functionalities), they must be described well.
B. Ontological description of e-Learning Web services
We used the OWL-S ontology for describing e-Learning
Web services of the fact that it allows the general description
of a Web service.
The e-Learning Web services can be distinguished
according to the functionality provided by each, someway
according to the quality of the functionality provided by each.
Accordingly, the pedagogical characteristics represent a very
important element during the choice of an e-learning Web