Reusable and Shareable Digital Course Libraries Christo Dichev Winston-Salem State University

Introduction 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.) 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 learners  efficient access to high quality learning materials.

Digital 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 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-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.

Problems 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 Organization Interbook - Typical Scenario

Hierarchical Organization (up)

Hierarchical Organization (down)

Hierarchical Organization (up)

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 representation  a navigable structure. –uniform incorporation of two different aspects  domain conceptualization, which supports findability  ontologies, which support reusability.

Course 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.

Standardization 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 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 A format W LO D format Z LO B format X LO C format Y

Two 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.

Ontology 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 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 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 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 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 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 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 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 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 Maps ISO 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.

From Real World to TM

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 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”

Omnigator: The ‘Prolog” Topic

Omnigator: The ‘Lists’ Topic

Advantages 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 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 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.

Numbering System

Two’s Complement Format

Binary Logical Operations

AND

The ER Model Topic Map

Using 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 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 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 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 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 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.

Conclusion 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 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.

References ISO/IEC JTC 1/SC34 Information Technology - Document Description and Processing Languages. The Standard Application Model for Topic Maps. Ontopia Knowledge Suite Dublin Core Metadata Initiative. Advanced Distributed Learning (ADL) (2001). Sharable Content Object Reference Model (SCORM). The SCORM Content Aggregation Model. Version 1.2. October 1,