|Abstract: ||With the rapid development of the Internet, e-learning systems have become more
and more popular. For sharing and reusing teaching materials in different e-learning system,
the Sharable Content Object Reference Model (SCORM) has become the most
popular international standard among the existing ones. In an e-learning system, teaching
materials are usually stored in a database, called the Learning Object Repository (LOR).
In the LOR, a huge amount of SCORM teaching materials, including associated learning
objects, will result in management problems in a wired/wireless environment. Recently,
the SCORM organization has focused on devising ways to efficiently maintain, search,
and retrieve desired learning objects in LORs for users. This effort is referred to as the
Content Object Repository Discovery and Resolution Architecture (CORDRA).
In this paper, we propose a management approach, called the Level-wise Content
Management Scheme (LCMS), that can be used to efficiently maintain, search, and retrieve
learning contents from a SCORM compliant LOR. LCMS includes two phases: the
Construction phase and Search phase. In the former, the content structure of SCORM
teaching materials (Content Package) is first transformed into a tree-like structure, called
a Content Tree (CT), to represent each piece of teaching material. Based on Content
Trees (CTs), the proposed Level-wise Content Clustering Algorithm (LCCAlg) then creates
a multistage graph showing relationships among learning objects (LOs), e.g., a Directed
Acyclic Graph (DAG), called the Level-wise Content Clustering Graph (LCCG).
The LCCAlg determines the relationships among LOs in different teaching materials by
clustering all of the LOs for each level from bottom to top, according to a similarity
measure. Moreover, a maintenance strategy is employed to rebuild the LCCG if necessary
by monitoring the condition of each node within the LCCG. The latter employs the
LCCG Content Searching Algorithm (LCCG-CSAlg) to traverse the LCCG and retrieve
desired learning content with both general and specific LOs, according to queries sent by
users in the wire/wireless environment. Some experiments have been done conducted to
test the proposed scheme, and the results are reported here.