Towards an Ontology to Describe the Taxonomy of Common Modules in Learning Management Systems.

 Abstract — This article have the objective a create ontology for "common modules in a Learning Management Systems", the steps for the build Ontology were: Determine the domain and scope of the ontology, Consider reusing existing ontology, Enumerate important terms in the ontology, Define the classes and the class hierarch, Define the properties of classes—slot and Define the facets of the slot, finally be explained how the ontology is composed.


I. INTRODUCTION
very big problem that found in the integration or migration of platforms e-learning or Learning Management Systems (LMS ) is the incompatibility between these, this incompatibility is due to lack of unification regarding the appointment and composition of modules and submodules that integrate the different LMSs, for example the module file management in the Atutor platform is named "File Administrator" while that in others platforms how Claroline or Mooodle is named "Documents" and "Resources" respectively.
Before to working with the LMS platforms is necessary selecting LMS platforms. In this sense we divided the LMS platforms in two types; the private platforms how is the case of BlackBoard and the Open Source platforms how is the case of Moodle.
Due to huge amount of LMS platforms that there in the in the market, is necessary select the most commonly used. For the selection of LMS, we chose Moodle, Sakai, and DotLRN because works such as [1] show that Moodle is the most used open source LMS in Spanish Universities with over 45%. Furthermore, Sakai has 5%, and DotLRN has 4%. Claroline and ATutor were selected because they are also used worldwide. For instance, according to [2] each of these platforms are used by 3% of the Italian Universities.
This article presents an ontology of modules common in LMS platforms, in the first stage had been realized the -MODELING AND COMPARISON STUDY OF MODULES IN OPEN SOURCE LMS PLATFORMS WITH CMAPSTOOL‖ [3], in this moment was tested five LMS (Moodle, Sakai, DotRLSn, Claroline and Atutor), for each of them is constructs your knowledge map with CmapTools and was obtained a comparative table between its modules. This result is the information source for built the ontology. For the construction of the ontology, the methodology used was -Ontology Development 101: A Guide to Creating Your First Ontology‖ [4] and this step is developed in the section 2, the section 3 explained the ontology composition and finally in section 4 are located the conclusions.

II. METHODOLOGY FOR CREATING ONTOLOGY.
For the creating ontology we used the guide official for the ontology development that Stanford University recommend, Stanford University is the creator of protege [4] and the name of the guide is -Ontology Development 101: A Guide to Creating Your First Ontology‖ [5]. Here define the concept of the ontology how -is a formal explicit description of concepts in a domain of discourse (classes (sometimes called concepts)), properties of each concept describing various features and attributes of the concept (slots (sometimes called roles or properties)), and restrictions on slots (facets (sometimes called role restrictions)). An ontology together with a set of individual instances of classes constitutes a knowledge base‖ [5] and proposed a methodology for the construction of ontologies, comprising the following steps: The following chapters develop the proposed methodology adapted to our special needs. respect to coding standards, uses the same Java recommended [6].
Towards an Ontology to Describe the Taxonomy of Common Modules in Learning Management Systems.
A. Determine the domain and scope of the ontology. The problem domain this bounded, to the management of an LMS Components and especially of the LMS appointed in the section one, with a focus at the creation of courses. The Ontology is employed for the get respect necessary knowledge at the modules that make up a LMS and the create courses within him, Similar modules or homologous modules between LMS, the ontology may answer questions as ¿A forum is part of the tools of the LMS? Or ¿a teacher is a type of user of a LMS? it's very important clarify that ontology is created to a changing and evolution context, therefore it is necessary maintain, upgrade and expand according to the context need for the ontology.

B. Consider reusing existing ontologies.
To consider progress in the area of ontologies for LMS, we made a search of available ontologies, in order to work and enrich more, the search was conducted in the following browsers ontological, Recommended in [5]:   [11]. The search was unsuccessful in these containers and browsers ontological, since all ontology were offered concept of Learning Management System, but do not model the ontology of the LMS, so it is not feasible to use one of these ontologies.
The next step was to find an ontology is search in the academic databases such as ISI Web of Knowledge, Springer, Ebsco, Dialnet, Proquest, ACM, IEEE, Google Schoolar and other similar, there are some jobs such as:  A Learner Oriented Ontology of Metadata to Improve Effectiveness of Learning Management Systems: This paper presents ontology for an e-Learning Management System (LMS), which arranges metadata, and defines the relationships of metadata, which are about learning objects; belong to academic courses and user profiles. This ontology has been incorporated as a critical part of the proposed architecture. By this ontology, effective retrieval of learning content, customizing LMS is expected. Metadata used in this paper are based on current metadata standards. This ontology specified in human and machine-readable formats. In implementing it, several APIs were defined to manage the ontology. They were introduced into a typical open sourced LMS. Proposed ontology maps user preferences with learning content to satisfy learner requirements. These learning objects are presented to the learner based on ontological relationships. Hence it increases the usability and customizes the LMS [12].  Towards an ontology about LMS: This article is a review of the LMS concept and proposes ontology based on the latest definitions. This article is part of an investigation in progress that aims to clarify the systemic quality in the process of implementing an LMS in an organization [13].  Justification and description of the domain of knowledge of an Ontology for the formalization and automatization of education scenaries: This article justifies the need to build an ontology with order to provide technical support for a specification of learning scenarios and a tool for development and validation of new scenarios. Specifically, it justifies the need for ontology and described in natural language the first approach to domain knowledge of it [14].  Knowledge Representation of LMS using Ontology: Though there are no distinct classifications of the approaches while implementing, the union of all the viewpoints is not dealt / applied completely by any of the author. This paper focus on integrating the above said principles on semantic educational servers with the power of eLearning standards. The knowledge items (learning objects) are linked to commonly agreed ontology [15].  Towards an ontology of lms a conceptual framework: This article presents a research in progress whose final objective is to develop a method to select, implement and integrate an LMS into an organization with a systemic quality approach. As a first step, in this article is presented an ontology to conceptualize the terms associated to LMS, unifying them through their relations [16]. All these papers raise the creation of an ontology in their respective contexts and approaches made to the ontology, but not analyzed common modules between LMS platforms, All these ontologies are used as input for the a ontology building common between some LMS platforms.

C. Enumerate important terms in the ontology
For the enumeration important terms we used a list of terms available in [3], in this list is presented a approximation of modules compatible between LMSs and a generic name for them to define the LMS ontology, this is shown in the table 1.

D. Define the classes and the class hierarchy
For the definition of the classes, we chose a combined process mix between top-down process in which one begins by defining the general concepts and lay the composition of these, for example a course has tools, and process bottom-up which begins with the definition of more specific classes and then generalized, for example a forum is part of communications.
The end result of this step, we can see in Figure 1.

E. Define the properties of classes-slots
The properties of the classes are defined basing on types of components that they have, this classification of the components had already been done on the job [3](to appear), using the leaf nodes used knowledge maps for each class used in the ontology, is searched common components in knowledge maps for example, in the conceptual maps of moodle and claroline for the Forum module, we can determine that the common elements for the forums are: forumName, message, subject and attachment is optionally, this means that these are the properties of our classes and are of type: textBox, textBox, textBox and file respectively why this is shown in the leaf nodes, the Figure 2 show the members of the Foro Class and Figure 3 show the type of forumName.

F. Define the facets of the slots
Here we define the facets that describe the type of value, valid values, the number of values (cardinality) and other characteristics that the slots can take, for example the item evaluationDate is a type calendarDate and the values it receives only Activity_Calendar, are as shown in Figure 4 and the same types of securities may be as common as strings or numbers.

G. Create instances
This last step is not proved, because not is provided in the scope of the this article and our case will be the responsibility of the domain specific language for the generation of learning management systems modules [17], this project was developed in the Informatics department of the University of Oviedo.

III. ONTOLOGY GENERATION
The generated ontology is composed of 50 classes including the Thing Class, 4 Object Properties, 16 Data Properties, 69 Individuals, each of these components with their respective descriptions the more general classes are LMS, Learning_Objects and Standars_E-Learning, this classes show in the Figure 5, their classes visualization is done in Asserted class hierarchy of Protege ant the view offered by OWLViz Plugin. The LMS Class has Users and Tools, the Users has assignetRol, e-Mail, password and UserName how members of him, and the Tools class has the subclasss: Tools Administrations, Communications, Course, Curricula_Desing, Productivity, and Student, Figure 6 shows these classes.  The Communications class is son of Tools class and have seven subclasses; Announcements, Calendar, Chat, Forums, News, Note and Wiki. The Announcements class, have a announcementText of textArea type. The Calendar class, have a showCalendar of calendar type. The Chat class, have a roomName of textBox type, send of button type, sendText of textBox type, textWrittenByUsers of nonEditableTextArea type and userList of list type. The Forum class, have an attachment of file type, forumName of textBox type, message of textBox type and subject of textBox type. The News class, have a newsBody of textArea type, newsDate of textBox type, newsLead of textBox type and newsTitle of textBox type. The Note class, have a message of textBox type, send of button type and userName of textBox type. And the Wiki class, have a wikiEdit of textArea type and wikiView of view type. All This is show in figure 8. Activity_Calendar, Calification_System, Evaluation_System, FAQ, Glossary and Groups. The Activity_Calendar class, have a activityDay of calendarDate type, activityDescription of textaArea type, activityName of textBox type and attachment of file type. The calification_System class, have a activityName of textBox type, commentsCalification of textArea type and valueCalification of textBox type. The Evaluations_System class, have a calificationMethod of textBox type, evaluationDate of calendarDate type, statementQuestion of textArea type, and has three subclasses, Matching class that additionally has, matchingQuestion1, 2, 3, 4 to n of textBox type and matchingResponse1, 2, 3, 4 to n of textBox type. Multiple_Choise class that additionally has, MultipleResponse1, 2, 3, 4 to n of textBox type and percentageHitResponse1, 2, 3 ,4 to n of textBox type and True_Or_False class that additionally has, falseResponse of textArea type and trueResponse of textArea type. Other sons of Course class, are FAQ class, have a viewFAQ of textArea type, Glossary class, have a viewGlossary of textArea type and Groups class, have a userList of list type. All This is show in figure 8.      The LMSs use a different Standards, but the principal modules its similar in all standards, but the problem is that technology implementation in each LMS is different and this is cause of incompatibility, is necessary create a method for the create modules independent of the platform, one solution could be applied Model Driver Engineering or web services, or other technologies.
The previous step for the perform the ontology, is know the domain of the context, And a good way for this, is interact and navigate for each of the platforms, for exploring the modules that comprise it.