| Abstract |
Many standards have been defined aiming at supporting interoperability of systems and learning objects as well as accessibility, adaptability and reusability of them. The SCORM set of specifications is the most widely adopted. However, existing e-Learning platforms fail to conform to one specification included in SCORM. This is the SCORM Sequencing and Navigation Specification, which is based on the IMS Simple Sequencing specification, and provides a method for representing the intended behavior of the sequencing and navigation in learning material based on data models and provides a description of basic behaviors that an e-Learning platform should exhibit. A SCORM conformant sequencing engine will be implemented based on the Web Services paradigm and principles of the Service-Oriented Architecture (SOA). The basic concept of SCORM, the Sharable Content Object (SCO) and its functionality will be wrapped by Web Services using the Web Service Resource Framework. Additionally, the sequencing behaviors will be also represented by Web Services and their composition will finally result in the implementation of the sequencing engine. The composition of Web Services that represent the sequencing behaviors will be implemented according to the Business Process Execution Language (BPEL), which is a SOA standard for orchestrating services. The usage of Web services and BPEL process will provide us with a plug-and-play sequencing engine that can be easily integrated in existing e-Learning platforms . The only requirement is a simple call to the BPEL process. Furthermore, the Web Services wrappers of SCOs will give us the opportunity to reference and deliver learning materials residing in remote repositories eliminating the need to package them and importing to local repositories. Moreover, the use of Web Services for implementing functionalities of e-Learning platforms will lead to more flexible systems as new services will easily replace the existing ones.
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A scorm conformant sequencing engine based on WS-resource framewοrk and principles of service oriented architecture
