January 2012 Volume 15 Number 1 - Educational Technology ...

Figure 1. In the URI layer, there are a number of learning objects, including XML Advance, XHTML Introduction,
JAXP for XML, Java DOM, etc. In the XML layer, each learning object is described with a LOM-based metadata
document that consists of classification metadata and relation metadata. These metadata can be summarized in Table
1 and Table 2 respectively. Each row in Table 1 denotes a classification concept in the LOM document, which is
associated with a semantic clue that is the classification metadata of LOM. The value of a classification metadata can
be mapped to an ontology class to inherit semantic knowledge. Each row in Table 2 denotes a relationship concept in
the LOM document, which is associated with a semantic clue that is the relation metadata of LOM. The value of a
relation metadata can be mapped to an ontology property to capture semantic relationships.
Table 1. The classification of learning objects
learning object ID classification: ontology#class physical learning object
cu-1 http://..../SoPro.owl#XML http://…/xml.htm
cu-2 http://..../SoPro.owl#XHTML http://../xhtml.htm
cu-3 http://..../SoPro.owl#DOM http://../jdom.htm
cu-4 http://..../SoPro.owl#JAXP http://../jaxp.htm
Table 2. The relation between learning objects
start ID end ID relation: ontology#property
cu-1 cu-4 http://..../SoPro.owl#XMLParser
cu-2 cu-1 http://..../SoPro.owl#standard
cu-4 cu-3 http://..../SoPro.owl#using
Two instances from the Table 1 and Table 2 are further revealed as follows. The classification metadata of "XML
Advance" (i.e. cu-1) is annotated with the following metadata.
learning object ID "cu-1" represents the "XML Advance" learning object.
classification address the "XML Advance" is an instance of XML class. Therefore, "XML Advance" can inherit
semantic knowledge from XML class.
URL "http://sparc.nfu.edu.tw/~hsuic/el/xml.htm" provides physical location of "XML Advance".
Figure 4. The query interface of LOFinder
307