Reusable and Shareable Digital Course Libraries Christo Dichev Winston-Salem State University...
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Transcript of Reusable and Shareable Digital Course Libraries Christo Dichev Winston-Salem State University...
Reusable and Shareable
Digital Course Libraries
Reusable and Shareable
Digital Course Libraries
Christo Dichev
Winston-Salem State University
www.wssu.edu/~dichevc/
IntroductionIntroduction
E-learning - use of new information technologies and media to deliver, support and enhance teaching, learning and assessment
Depends on more than just providing the technology and equipment – The proportion of the effort that is required both to
develop learning material and to find relevant learning resources
– Support for organizing and classifying the learning content so that the learner and the instructor can find what they need when they need it.
Introduction (cont.)Introduction (cont.)
E-learning gains a rapidly increasing popularity in college education and business training.
Its efficiency depends on the cost of – developing learning material by instructors (authors)
share, reuse, and exchange existing teaching units
– retrieving relevant learning resources by learnersefficient access to high quality learning materials.
Digital LibrariesDigital Libraries
Possible solutions to these problems – digital libraries– educational portals
Digital libraries (DL) are typically discipline -specific catalogued collections of digital objects that can be used in disciplinary teaching, learning, and research – contain hypertext/hypermedia documents and support
document-level retrieval – the content is shareable but barely reusable &
interoperable.
Digital Library ProgramsDigital Library Programs
Goals– Coordinating efforts for establishing an online network
of resource collections and services – Serving as a forum where ‘resource users may
become resource providers’ – Offer learner-centered educational materials and
environments NSF NSDL
– "Towards Reusable and Shareable Courseware: Topic Maps-Based Digital Libraries"
– To assist students’ learning in a specific discipline and course-related work (e.g. projects, assignments, etc.)
Digital Libraries for e-LearningDigital Libraries for e-Learning
A good digital course library should provide: Learners with
– access to sufficient amount of relevant educational resources
– powerful and intuitive search tools.
Authors with– support for reuse and sharing of teaching and learning
material.
ProblemsProblems
Two main groups of problems related to using existing courseware & specialized educational collections – reusability of existing repositories of learning resources by
instructors existence of shared agreement on repositories’ content standards-based representation.
– findability of information learners are often unaware of the context of the task and
need help in getting oriented in the subject conceptual structure.
broadly exploited hierarchical organization typically does not support “conceptual” navigation.
Hierarchical OrganizationInterbook - Typical Scenario
Hierarchical OrganizationInterbook - Typical Scenario
Concept-based, Ontology-aware Digital Course Libraries
Concept-based, Ontology-aware Digital Course Libraries
Framework for building of concept-based ontology-aware digital course libraries– driving idea - use of a network of concepts both as
a medium of domain knowledge representationa navigable structure.
– uniform incorporation of two different aspects domain conceptualization, which supports findability ontologies, which support reusability.
Course Library FrameworkCourse Library Framework
Conceptualization supports understanding of the specific subject domain by enabling exploration of related concepts.
Ontology captures the well-founded and broadly agreed system of concepts in the domain.
An architecture built within this framework utilizes the advantages of concept-based and standards-based content organization.
StandardizationStandardization
The actual costs and benefits of e-learning depends essentially on standardization. – To find the appropriate learning resource is not
enough. – The learning objects developed for a particular system
may not be reusable in others.
Proliferation of e-learning systems– Different vendors– Different architectures
E-learning StandardizationE-learning Standardization
Learning
System A
Vendor A
Learning
System B
Vendor B
Learning
System C
Vendor C
Learning
System D
Vendor D
Multitude of learning objects (LO)– Different formats– Different developers
LO Aformat W
LO Dformat Z
LO Bformat X
LO Cformat Y
Two PerspectivesTwo Perspectives
Addressing standardization of digital course libraries from two perspectives – technological perspective and knowledge perspective– Technological perspective - use of standards, such as
Dublin Core, the learning objects standard SCORM, etc.
– Knowledge perspective – use of specialized domain ontologies as a semantic backbone for e-learning repositories.
OntologyOntology
Ontology is a well-founded and broadly agreed upon system of concepts in a particular subject domain together with the relationships between those concepts – provides a common vocabulary for domain knowledge
representation – facilitates machine readability of Web content.
Courseware units can only be shared, reused, and exchanged among different authors if they agree on the vocabulary used in their construction.
Features of Concept-based DL Features of Concept-based DL
Key features of the proposed approach – building a conceptual structure that represents
domain ontology– using it for structuring and classification of digital
library content – linking learning objects (content) to the relevant
ontology terms (concepts)conceptual structure used to index library content.
Layered Information Structure Layered Information Structure
Semantic layer - modeling conceptually the knowledge domain.
Resource layer - including a collection of information resources associated with the knowledge domain.
Context layer - representing different views (contexts) on the library resources depending on a particular application, goal, type of users, etc.
Semantic LayerSemantic Layer
Two major benefits to learners:– Support for efficient context-based retrieval of
information items by allowing natural and intuitive concept-based browsing
– Support for exploration of the conceptual structure of the subject domain independently of the information resources
improvement of the overall understanding of the domain.
Scripts ExampleScripts Example Domain: Scripts and languages
Concepts: ‘Script’, ‘Script category’, ‘Script type’, ‘Language ’, ‘Country’, ‘Province’.
Relations: contains, instance of, used to write, spoken in, contained in.
Script category contains Script
Script instance of Script type
Script used to write Language
Language spoken in Country
Language spoken in Province
Province contained in Country
Dynamic Storage Management ExampleDynamic Storage Management Example
Domain: ‘indirect addressing’ and ‘dynamic storage management’– concepts: ‘pointer’, ‘dynamic variable’, ‘dynamic memory’,
‘dynamic memory allocation’, ‘dangling pointer’, ‘heap management’, ‘memory leakage’, ‘garbage collection’, etc.,
– relations: accessed_by, used_for, kind_of, reclaimed_by, etc.
‘dynamic variable’ accessed_by ‘pointer’, ‘pointer’ used_for ‘dynamic memory allocation’ ‘dangling pointer’ kind_of ‘pointer’, ‘heap’ kind_of dynamic memory, ‘dynamic memory’ reclaimed_by ‘garbage collection’, ‘heap management’ illustrated_by , etc.
Resource LayerResource Layer
Represents the information resources (learning objects) associated with the specific knowledge domain.
Learning Objects (LO) are– Internal: objects stored in the digital library. – External: Web objects referenced by their URI.
Context LayerContext Layer
Allows explicit representation of multiple contexts (views) related to different situations and/or users’ goals.
By providing different perspectives a user can access the same resources based on navigational strategies in different conceptual spaces – navigation through a specific sequence of course units
(topics) – exploration of learning content from a semantic
(conceptual) point of view, etc.
Supporting Exploratory WorkSupporting Exploratory Work
The proposed layered information structure of digital libraries is especially appropriate for supporting exploratory work that requires guided research.
Learning objects can be related to course work and connected with homework, project, and lab assignments.
Guided research in the context of online course environment assumes – sufficient set of resources
– conceptual layer providing meaning to the resources in terms of the interrelated concepts being taught.
Topic MapsTopic Maps ISO 13250 XTM standard - XML Topic Maps
(TM) – provides a paradigm for organizing and retrieving
online information and for interchanging semantic information on the Web
– with roots in traditional finding aids such as back-of-book indexes, glossaries, and thesauri
– knowledge representation applied to information management from the perspective of humans.
Topic Maps Paradigm Topic Maps Paradigm Can be viewed as an index of information which resides
outside that information – supports topical finding of various kinds of resources: documents,
graphics, images, database records, audio/video clips, etc. Appropriate for representing the proposed layered structure of
digital course libraries.
Topic Maps ModelTopic Maps Model Concepts (knowledge ‘elements’) - classified into objects called topics Relationships among topics: associations that have types and roles Topics can be addressed by one or more specific resources
(occurrences) Topics, associations and occurrences can be scoped for different
contexts.
“Tosca was written by Puccini” “Tosca takes place in Rome” “Puccini was born in Lucca” “Lucca is in Italy” “Puccini was influenced by Verdi”
“Tosca was written by Puccini” “Tosca takes place in Rome” “Puccini was born in Lucca” “Lucca is in Italy” “Puccini was influenced by Verdi”
Advantages of Using Topic MapsAdvantages of Using Topic Maps
Provide convenient and intuitive presentation of interrelated concepts embedded in information resources.
Learning material is in a standard XML format, which makes it interchangeable.
Topic maps merging allows a modular approach to TM creation– different users can share and combine their TM in a
controlled manner – promotes reusability, shareability, and interoperability.
Creating TM-based e-Learning Modules Creating TM-based e-Learning Modules
Phase I: Creating specialized ontologies in some fields of CS.
Phase II: Developing Topic map-based courseware using the developed ontologies.
Phase III: Evaluating the developed modules and the appropriateness of using the TM technology to develop concept-based courseware.
TM-based CS ModulesTM-based CS Modules
Common for at least two Computer Science courses - to experiment with reusing them. – “Number Systems”, relevant to “Computer
Programming I”, “Assembly Language Programming”, and “Computer Architecture”;
– “Prolog”, relevant to “Artificial Intelligence” and “Programming Languages”;
– Introduction to Entity-Relationship Model”, relevant to two Database courses and in the “Systems Design and Development” course.
Using TM-based DLUsing TM-based DL
We are planning to use the developed digital course library as an e-learning task-support environment aimed at assisting students in locating information necessary to perform course tasks (e.g. home assignments, projects, etc).
There are also other ways for using the Topic Map authoring tool in teaching & learning, e.g. students can be asked to create TM of particular course topics, etc.
Tools for Creating Concept-based DL Tools for Creating Concept-based DL
A successful application of Topic Maps to e-learning depends on the ease of their: – creation, – maintenance, – navigation, – retrieval.
ETM-Librarian, is aimed at supporting authoring and delivery (presentation) of learning material in a digital course library. – ETM Editor – ETM Viewer.
ETM Editor – Design CriteriaETM Editor – Design Criteria
Provide intuitive interface. Support to authors in developing topic maps, including:
– Editing and modifying existing TM-based learning objects.– Comparison and merge of learning objects.
Easy access and manipulation of TM constructs (i.e. specific topics, associations, and resources) using a custom language.
Support for finding and adding external information resources.
ETM Editor’s Functionality ETM Editor’s Functionality
Maintaining concepts: add concepts, delete concepts, link concepts to other concepts.
Creating learning objects: define learning objects, add learning objects, delete learning objects, modify learning objects, merge learning objects.
Creating contexts (organizing learning objects): link learning objects conceptually, organize learning objects hierarchically, define different views.
Import/export topic maps, i.e. ‘transport’ topic maps from one application (repository) to another.
ETM Viewer – Design Criteria ETM Viewer – Design Criteria Support two strategies for information seeking
– opportunistic and – analytical.
Intuitive presentation of resource and conceptual domains separated in two distinct layers.
Exploration of topic layer with access to needed resources.
Learner can see the topic, to which the currently inspected resource is related– Enables switching back and forth between the
resource domain and the conceptual domain.
ETM Viewer’s FunctionalityETM Viewer’s Functionality
Browsing the e-learning repository. Supporting orientation: showing the position during
browsing. Supporting perspectives: presenting information from
different viewpoints. Allowing change of navigation criteria at any time, e.g.
shift to a navigation path in another view. Keyword-based searching for learning objects in the e-
learning repository. Providing an option for external search on the Web.
ConclusionConclusion
Contributing to the development and use of efficiently searchable, reusable, and interchangeable discipline-specific repositories on the Web.
Proposing an environment supporting concept-based digital course libraries.
It targets two general categories of users – authors and learners: – for authors to conveniently create and modify learning
material, share it with other users, and reuse existing material,
– for learners to efficiently navigate and search for useful resources.
Future WorkFuture Work
Exploring further research questions related to using TM in educational aspects– how to represent and use instructional knowledge in
TM; – how to model the learner and use this knowledge for
‘library adaptation’, etc. Information support necessary for ‘opening’ of a
digital course library to the Web. – What kind of context can be used to constrain the
Web search and improve its quality and precision. Creating a substantial TM-based digital library
collection in Computer Science.
ReferencesReferences
ISO/IEC JTC 1/SC34 Information Technology - Document Description and Processing Languages. The Standard Application Model for Topic Maps. http://www.y12.doe.gov/sgml/sc34/document/0323.htm
Ontopia Knowledge Suite http://www.ontopia.net/solutions/products.html
Dublin Core Metadata Initiative. http://dublincore.org/ Advanced Distributed Learning (ADL) (2001). Sharable
Content Object Reference Model (SCORM). The SCORM Content Aggregation Model. Version 1.2. October 1, 2001. http://www.adlnet.org/.