Content-type: text/html Downes.ca ~ Stephen's Web ~ RDF Site Summary 1.0 Modules: Learning Object Metadata

Stephen Downes

Knowledge, Learning, Community

May 10, 2003

Authors

Stephen Downes, NRC E-Learning Group, Moncton

Version

Latest Version: http://www.downes.ca/xml/rss_lom.htm

0.5 10 May 2003

Status

Pre-Release

Rights

Copyright © 2003 by the Authors.

Permission to use, copy, modify and distribute the RDF Site Summary 1.0 Specification and its accompanying documentation for any purpose and without fee is hereby granted in perpetuity, provided that the above copyright notice and this paragraph appear in all copies. The copyright holders make no representation about the suitability of the specification for any purpose. It is provided "as is" without expressed or implied warranty.

This copyright applies to the RDF Site Summary 1.0 Specification and accompanying documentation and does not extend to the RSS format itself.

Description

The 1484.12.1 - 2002 Learning Object Metadata (LOM) was approved by the IEEE-Standards Association on June 12, 2002. The purpose of IEEE-LOM is to provide structured descriptions of re-usable digital learning resources, sometimes known as "Learning Objects." This standard was authored by the Learning Technology Standards Committee (LTSC) Learning Object Metadata Working Group and was based on previous work by the IMS Global Learning Consortium. Applications of the IEEE-LOM (as it is typically called) include the Sharable Content Object Reference Model and CanCore, among others.

The RSS-LOM Module provides translation from IEEE-LOM to RSS 1.0 to allow learning object repositories to syndicate listings and descriptions of learning objects. An RSS feed provided by a learning object repository is harvested by a metadata repository and aggregated with feeds from other learning object repositories. These aggregated feeds are then made available as a searchable resource, the links provided ultimately pointing to the learning objects provided by the original learning object repositories.

Note: though this document provides a complete translation from IEEE-LOM to RSS 1.0, much of IEEE-LOM is not useful for the present purpose. IEEE-LOM has a history of having been developed in a non-RDF environment and (therefore) in complete isolation from other XML initiatives. For most purposes, the use of Dubmin Core (DC) with only the educational and the classification schemas ought to be sufficient for syndication.

Namespace Declarations

Since IEEE-LOM is authored as flat XML, and since RSS 1.0 modules require specification in RDF, the IEEE-LOM RDF binding is used. This binding provides the following RDF schemas for use by RSS-LOM:

Please note that the IEEE-LOM RDF binding includes instances of Dublin Core as well. For completeness, those instances are reproduced below and the namespace declaration included here:

Model

Elements:

    /tr>

    General

    LOM ElementRSS 1.0 EncodingData Type
    1.1 Identifier#PCDATA
    1.2 Title#PCDATA
    1.3 LanguageRFC1766
    1.4 Description#PCDATA
    1.5 Keyword#PCDATA
    1.6 Coverage#PCDATA
    1.7 StructureLOM restricted vocabulary
    1.8 Aggregation LevelLOM restricted vocabulary

    Lifecycle

    2.1 Version#PCDATA
    2.2 Status#PCDATA
    2.3 ContributeVCard or #PCDATA
    VCard or #PCDATA
    VCard or #PCDATA

    Metametadata

    3.1 IdentifierSee 1.1
    3.2 ContributeSee 2.3
    3.4 Metadata SchemeResource
    3.5 LanguageSee 1.3

    Technical

    4.1 Formatdcterms:IMT
    4.2 Size#PCDATA
    4.3 Location#PCDATA URL
    4.4 Requirements#PCDATA
    #PCDATA
    4.5 Installation Remarks#PCDATA
    4.6 Other Platform Requirements#PCDATA
    4.7 DurationISO8601

    Educational

    5.1 Interactivity TypeLOM restricted vocabulary
    5.2 Learning Resource TypeLOM restricted vocabulary
    5.3 Interactivity LevelLOM restricted vocabulary
    5.4 Semantic DensityLOM restricted vocabulary
    5.5 Intended End-User RoleLOM restricted vocabulary
    5.6 ContextLOM restricted vocabulary
    5.7 Typical Age RangeLOM restricted vocabulary
    5.8 DifficultyLOM restricted vocabulary
    5.9 Typical Learning TimeISO8601
    5.9 Description#PCDATA
    5.10 LanguageRFC1766

    Rights

    6.1 CostLOM restricted vocabulary
    6.2 Copyright and Other RestrictionsLOM restricted vocabulary
    6.3 Description#PCDATA

    Relation

    7 RelationUse DCTerms#PCDATA

    Annotation Catgeory

    8.1 Annotation#PCDATA

    Classification

    9. ClassificationLOM restricted vocabulary
    LOM restricted vocabulary
    LOM restricted vocabulary
    LOM restricted vocabulary
    LOM restricted vocabulary
    LOM restricted vocabulary
    LOM restricted vocabulary
    LOM restricted vocabulary

    Example

     xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns="http://purl.org/rss/1.0/"
      xmlns:lom-general=" http://kmr.nada.kth.se/el/ims/schemas/lom-general" 
      xmlns:lom-life=" http://kmr.nada.kth.se/el/ims/schemas/lom-lifecycle"  
      xmlns:lom-metametadata=" http://kmr.nada.kth.se/el/ims/schemas/lom-metametadata"  
      xmlns:lom-tech=" http://kmr.nada.kth.se/el/ims/schemas/lom-technical"  
      xmlns:lom-edu=" http://kmr.nada.kth.se/el/ims/schemas/lom-educational" 
      xmlns:lom-rights=" http://kmr.nada.kth.se/el/ims/schemas/lom-rights" 
    > 
    DLORN
    http://www.downes.ca/dlorn.htm
    Distributed Learning Object Repository Network
    NRC E-Learning
    Stephen Downes (mailto:stephen@downes.ca)
    Copyright © 2003 Stephen Downes
    2003-05-09T12:00+00:00
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    DLORN Powered!
    http://www.downes.ca/images/dlorn.jpg
    http://www.downes.ca/dlorn.htm
    
    
    
    
    
    0-226-10389-7
    Sample Learning Object
    en
    A sample learning object metadata file in RSS
    psychology
    1776-07-04
    Atomic
    13
    beta
    final
    National Research Council
    Rod Savoie
    Stephen Downes
    
    text/html
    Multi-OS
    NetscapeCommunicator 4.7
    PT1H20M
    Active
    Exercise
    Low
    High
    Manager
    School
    7-12
    Easy
    PT1H20M
    This is intended to...
    en
    SomeCost
    SomeRestriction
       
    RightsBroker:RightsModel
    
     

    Notes

    1. Use of vocabularies

      IEEE-LOM has the habit of using internal metatags to indicate the use of a vocabulary. For example, for LOM element 1.1 (Identifier) the following format is suggested:

      
      
      0-226-10389-7
      
      
      
      This proposal makes two changes:
      1. First, it drops the internal tag (myVoc:ISBN in the example). If an external controlled vocabulary is used, it should be placed in the dc tag:
      2. Second, the tag is dropped. What else would it be?

    2. Language

      The IEEE-LOM specification advocated the use of tags throughout. In the IEEE-LOM RDF Binding, this is (happily) changed to the use of xml:lang="en" within the tag itself. In this document, the use of the language designation is proposed only if the language within the tag is different from the language specified in the <dc:language> element.

    3. LOM Restricted Vocabulary

      The IEEE-LOM RDF binding recommends an explicit declaration of the restricted IEEE-LOM vocabulary. For example:

      
      
      Until formal ontologies for IEEE-LOM vocabulary are available, this document recommends depicting the content as a string (#PCDATA); when ontologies are used, the ontology of reference would be contained in the tag, as in the case of point 1, above.

    4. VCard

      VCard data really has no place within an RDF document, however, it is scattered throughout IEEE-LOM and the RDF binding. Hence, the reference to VCard data is carried over into this document, with the expectation that one day a more rational system for identifying contributors will be implemented across RSS-space.

    5. Requirements

      Only a subset of the requirements specification is presented in this specification. It is anticipated that a proper RSS requirements module will be forthcoming that will do a proper job of this. Neither IEEE-LOM nr the RDF binding provide appropriate descriptions of OS, browser, plug-in or viewer requirements. Browsers and operating systems are assumed to be minimum versions, which is obviously inadequate.

    6. Learning Resource Type

      This is very poorly designed in both IEEE-LOM and the RDF binding, which recommends (incorrrectly) the use of rdf:type. Accordingly, a new tag, lom-edu:type is proposed, the values of which are specified by the LOM restructed vocabulary. This will probably be rewritten in IEEE-LOM once people try to use this tag.

    7. Rights

      The pitiful IEEE-LOM description will be replaced. See IEEE-LTSC-DREL. The "RightsBroker:RightsModel" in the example anticipates the eduSource DRM model.



Stephen Downes Stephen Downes, Casselman, Canada
stephen@downes.ca

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