The Research On The Construction Of Learning Content Based On The Media Material Database

The demanding prompt solution for the modern advanced distance education is how to enrich the educational resource extremely so as to meet the needs of the learner. It is well known that man's knowledge has a wide range in quantity and has also indefinites in quality. Theoretically, it is very difficult to construct a full learning network. This is due to a variety of causes, such as, the increasing complexity, diversity and terminological fluctuations of the different sources, etc. This thesis mainly studies the media material database of the modern distance education system based on the repeated usable learning object.Based on the component theory of pedagogies and on analyzing the structure of media material database among advanced distance education resource warehouse, we are mainly concerned with three aspects in this thesis: metadata of media material database, how to organize and express the learning content in the aid of the media material which described by metadata, and the distance education system realization in above two preconditions.In the field of metadata standard, the general characteristic and role of metadata are studied in this thesis, and then the metadata standards of the existing educational resource are analyzed. In general, the metadata standards were established for different applications. This thesis proposes a new metadata layer structure based on the composition, character and usage of media material database. We call it three-tiers metadata, which includes: metadata essential dataset, metadata basic dataset and metadata detail dataset. Meanwhile the elements and attributes of the detail dataset are introduced and the formal and canonical description of the detail dataset are also given by means of XML. For metadata element of media material database, the description of XML makes it possible to exchange with other international reference metadata standards. It can be used to construct an opening metadata space.In the field of the organization and expression of learning content, the teaching pattern, instructional strategy as well as design are introduced in this thesis. Hence, by combining "student-oriented" with "instructor-oriented", the mixture-teaching pattern and the hierarchy analysis method to decompose the learning goal are determined in the modern distance education. In order to construct the concept mapping, a STAR algorithm is given.The support of pedagogies and the metadata of media material database lay solid foundations for composing the learning contents. This thesis analyzes the component structure of learning space and presents three layers: unit layer, concept layer and entity layer. The relationships among these objects as well as possible existing manipulation are carefully studied. Theoretically some problems, which the constitution issue of learning content located in unit layer, are solved, by using the media material locates on the entity layer. Based on the three layers of learning space, the learning content is acquired from the correlation operation in the intra-relation and inter-relation, moves from the unit layer to the concept layer and entity layer, and finally, stops at entity layer.This thesis transforms the composition of learning content into the logic cluster of correlative concepts in the concept layer, and proposes the idea of learning content hierarchy graph. By means of the AND/OR graph of artificial intelligent theory, we can transform the learning content into the problem of AND/OR tree further. Hence, we conclude that the learning content is a tree, the root is learning goal, the branch node is correlative concept, and the leaf is media material.Based on the above works, the distance education resource warehouse is improved in this thesis by adding the storage and management of media material metadata and learning content hierarchy graph; the learning model of distance education system is improved and introduced. The transformation algorithm between learning content hierarchy graph and AND/OR tree is given.Finally, the...