A Study On The Mechanism Of Cognitive Load And Knowledge Map Based Adaptive Presentation

Online learning is the focus of current discussion. Increasing courses are delivered through Web, and the Web has become an important means to support distance education and lifelong learning. However, some research found that learners often get information overloaded in hypermedia space. Web provides us a great deal of information, but learners would be overloaded when they deal with too much information. Meanwhile, due to the lack of direct and guidance, learners cannot find the material that is fit to them. This may affect learner's confidence and interests in online learning.Adaptivity is a new trend of online learning, and the existing online learning systems or web courses have a lot to change on offering students appropriate guidance. In recent years, the study on cognitive load has made great development, and begins to switch from basic research to application research. Thus the research suggested a "Cognitive Load and Knowledge Map Based Adaptive Presentation", which can identify how much an individual learner has grasped a concept through diagnostic and formative evaluation strategies, and give adaptive learning material according to individual learner's knowledge level. The mechanism enhances the adaptivity of web hypermedia learning system, and better satisfies the needs of learners.In order to validate the feasibility of this method, the researcher designed a prototype system, using the fifth lesson of JAVA Technology course. The work can be summed as follows: First, decompose and reconstruct adaptive web course structure through cognitive load theory and the structural knowledge representation of knowledge map. Second, identify how individual learner grasps each concept through item attributes table and the improved concept cumulative-count algorithm. Third, present adaptive learning material to learners according to their state of knowledge.By the analysis on the research problem, the experiment on cognitive load by dual-task method and the design and development of the CKBALS, the research concluded: intrinsic cognitive load varies with the difficulty of task, which can be useful in adaptive learning system and according to this the system will be adaptive. Learner model based on domain model and concept hierarchy can describe an individual learner's knowledge level, which is the basis of system's adaptive behaviors. Carefully designed unit quizzes can identify learners' knowledge levels, and help to predict learners' succedent behaviors. Presenting adaptive learning materials according to learners' learning abilities on some concept can help learners to learn more efficient, and reduce the possibility of cognitive overloaded.