A web-service-based e-learning service infrastructure for achieving dynamic and collaborative e-learning.

摘要

Multimedia data and application systems that are accessible over the Web are valuable assets for developing instructional materials for teaching, training, problem solving and decision support. These assets can be used for constructing learning objects, each of which is a reusable granule of instruction designed to meet a specific instructional objective. In order to search, access, and deliver the learning objects, an infrastructure for the registration, discovery, and invocation of these objects is required. Also, there is a need to develop infrastructural technologies to enable general Internet users, not just students and educators, to engage in life-long instruction and learning. These technologies should allow the establishment of many virtual e-learning communities, each of which is formed by people with a common interest in exchanging knowledge useful for problem-solving and decision support in a specific problem domain.; In this work, we model distributed and sharable learning resources by two types of Learning Objects (LOs): Atomic Learning Object and Composite Learning Object. Both types of LOs are uniformly published as Web-services in a constraints-based Web service broker. XML-based languages for modeling these two types of LOs are defined. The languages also serve as the interchange formats for transferring and sharing LOs.; We have developed an e-learning service infrastructure that facilitates the authoring, registration, discovery, storing, and invocation of LOs. The infrastructure is built on top of an extended Web-service framework, which leverages the constraints-based Web service broker and distributed LO repositories to make LOs searchable, sharable and reusable. A set of distributed software components has been developed to provide e-learning services. It includes authoring tools for constructing LOs, and a Learning Process Management System for the registration, management and delivery of LOs and the assessment of learners' comprehension. The techniques used to achieve active, adaptive, flexible and customizable execution of learning processes such as dynamic binding to LOs, rule-based execution of learning processes that makes use of the profiles and runtime status models of learners, and model-based assessment are presented. The roles and functions of virtual e-learning community members are also discussed.; The e-learning technologies we developed have been applied to encapsulate the instructional materials of the Web-based Virtual Anesthesia Machine and the simulator as LOs, deliver instructional materials to learners, use the simulation system for practice, and perform assessment. Several techniques, such as retrying or disabling activities depending on a learner's profile, performance and needs, dynamic binding to suitable learning objects, optional assessment presentation, and the support of different learning approaches by customization of sequencing control modes, have been applied to achieve personalized learning.