Research On The Extension And Ontology Model Of ADL/SCORM Content Aggregation Mode

With the booming development of network technology, the modern distance education has been rapidly promoted at home and abroad, and applied widely in the education field, as has become one of the mainstream education developments either international or domestic. Because of the universality and complexity of computer network, however, there still are many bottleneck problems on the development of distance education at the present, the toughest issues of which are sharing and interoperating learning resources among various learning systems. The key to solve this problem is the distance education technical specifications, which provide a series of standardized method of learning materials and learning platforms in order to ensure the shareablity and the interoperability of them. Among all kinds of specifications published by International Organizations, the SCORM specification, released by the ADL, has been get broad support and research at the current field because of its marked advantages such as accessibility, adaptability, affordability, durability, interoperability, reusability. At present, the research works on the ADL/SCORM are mainly centered on Development of tools or systems on SCORM, application of SCORM technology to various distance learning courses, retrieval technique of learning objects conformed to SCORM, extension of SCORM model, application of Ontology to the SCORM learning environment, etc. this thesis carries out the SCORM research mostly from two distances, extension research of the Content Aggregation Model of SCORM and construction of learning content ontology model based on SCORM. The contribution and innovation of this research show as follows:The first place, a learning content sequencing method based on the Function Components is proposed in this thesis. The method is designed with the purpose of improving the SCORM model's reusability and flexibility in actual practice. Because the content packaging elements describing content structure is mixed in SCORM with the sequencing elements describing learning sequencing of the contents, there are some serious limitations in the definition of learning activities, such as unclear structure of the Content Organization, the lack of readability of the Content Manifest, etc.. Moreover, the SCORM reusing components can not support to adjust its parameters in response to changes of context, because the current mechanism for reusing components in SCORM is just simple reference of elements. The method presented by this thesis is to extend an element in the Content Manifest, called Function, which is used to define reusing sequencing components in order to separate sequencing elements from the content structure. At the same time, this method requires to extend a function-call element, called Call, which is designed for content elements to reference defined components.The second place, this thesis put forward a Domain Knowledge Base Exchange Model based on SCORM. Its technical innovation is to extend the application of SCORM model into the domain knowledge base field. The design of this model is dependent on the related instructional theory on the domain knowledge base and SCORM Content Aggregation Model. In the model, the SCORM not only acts the role of the model principle but also is extended in according with the practical feature of knowledge base in this thesis. This thesis specifies the details about how to use the SCORM model for representing the learning domain knowledge model so as to standardize the domain knowledge base for its interoperability and shareablity among different learning systems.The third place, this thesis presents a content aggregation Ontology model based on SCORM. By analyzing the latest E-learning research of ontology technology and the features of SCORM XML banding, this thesis provides a learning ontology model. The model is designed for overcoming the shortcomings that existing SCORM XML information model can not provide specific semantic information for the SCORM. This model, based on the SCORM Content Aggregation Model and the SCORM Sequencing & Navigation Model, provide a ontology method to define in content object how to sequence learning activities and how to organize learning resources in ontology. This model concludes element hierarchies and constraint axioms. Among them, the element hierarchy defines all of the SCORM elements and relationships between them. The constraint axiom is a set of formal axiom that axiomatically describes the semantic constraints of elements in the element hierarchies. This thesis investigates the feasibility and advantage of ontology SCORM information model that regard the ontology language as SCORM model language. Moreover, based on SCORM elements, attributes, relationships, and semantic constraints on them, the author discusses how to use ontology technology to make up the SCORM information model, which include SCORM model's class, object properties, data type properties, information model axiom, and etc.The fourth place, this thesis discusses the implementation technique of the ontology SCORM learning object model. By analyzing and comparing all kinds of ontology languages, language OWL is selected as the model building language of the SCORM ontology model. Then, this thesis discusses the specific methods to build the ontology model in OWL, which includes how to define XML entities, namespaces, classes, properties, range restriction axioms, necessity restriction axioms, uniqueness restriction axioms, content packaging axioms, sequencing & navigation restriction axioms, etc.. Based on the representation of OWL, this thesis advances the conversion methods of SCORM learning object between in XML and in OWL. Moreover, an example is taken to explicate the method of modeling the SCORM objects. Finally, there are two ways to apply the ontology learning model in practice, which are the development of full ontology-supporting Learning Management Systems (LMSs) and the extension of existing LMSs for supporting ontology. The program of this thesis has practiced the OWL LMSs by the means of extending the Importing Course Module of the SCORM 2004 3rd Edition Sample Run-Time Environment.