UNIVERSAL - Design and Implementation of a Highly Flexible E-Market-Place for Learning Resources Stefan Brantner*, Thomas Enzi+, Susanne Guth+, Gustaf Neumann+, Bernd Simon+ +
*
INFONOVA E-mail:
[email protected] Seering 6, A-8141 Unterpremstätten, Austria
1.
INTRODUCTION
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2.
ethical case study on Henkel in the Asian-Pacific Area; A live session of the course “International Marketing” dealing with an case study on Levi Strauss; Slides, exercises, and support material from an introductory course in “Information Technology and Management Communication” dealing with the creation of effective documents.
THE UNIVERSAL SYSTEM ARCHITECTURE
The UNIVERSAL platform comprises various engines (see Figure 1) providing services to users and external information systems such as local learning management systems, web-based content databases and ERP solutions of HEIs. An engine is related to a particular application providing a set of services and an interface to other applications. UNIVERSAL Engines
UNIVERSAL Repository
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User Interface
The European IST-Project “UNIVERSAL - Universal Exchange for Pan-European Higher Education” (http://www.ist-universal.org/) is an attempt to demonstrate an open exchange of learning resources (LRs) between higher education institutions across Europe [see 1]. The business-to-business oriented brokerage platform is designed to support offers, enquiries, booking and delivery of LRs. UNIVERSAL will enable collaboration among leading Higher Education Institutions (HEIs), by providing exchange services. The aim of UNIVERSAL is to increase the quality and competitiveness of HEIs through a cooperative – and, at the same time, competitive – environment [see 2, 3]. The subjects of exchange on the UNIVERSAL platform are LRs. LRs are more than a link to a faculty member’s homepage; they are defined as academic content devoted to a specific subject. An LR can be a part of a lesson, but can also span several lessons. It is not necessarily identical with a course, a unit which is restricted by the academic calendar of an HEI. The platform supports synchronous as well as asynchronous LRs. The following examples of LRs are taken from the preliminary version of the UNIVERSAL catalogue: • A recorded session of the course “Corporate Strategy in Emerging Markets” dealing with an
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User Interface
This paper illustrates the design and implementation of a highly flexible, electronic market-place for learning resources called UNIVERSAL. Integrating learning resource related data in a (semi-)automated way demands a flexible data model. The paper elaborates on components of an educational market-place model such as learning resources, agents, rights and delivery systems. The central data formats of UNIVERSAL are based on RDF. We argue that the flexibility of RDF provides a high level of adaptability to future changes in the data model and a maximum level of openness. UNIVERSAL aims at contributing to the idea of a semantic web of universities, pursuing the vision of having data on the web defined and linked in such a way that it can be used by machines not just for display purposes, but for automation, integration and reuse of data across various applications.
Vienna University of Economics and BA Department of Information Systems, New Media E-mail:
[email protected] Augasse 2-6, A-1090 Vienna, Austria
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Figure 1: UNIVERSAL Engines When it comes to the provision of LRs, the metadata engine facilitates the maintenance of LR related data. The engine interacts with LR providers via a web-based user interface, or uses a protocol to exchange data with local learning management systems. The LR metadata engine also facilitates access to the LR repository. Thus, on the one hand, the system has to provide flexible search services, allowing users to enter and combine queries as powerful search engine does. On the other
hand, it enables users to browse a well-structured directory based on an international taxonomy. The contract engine is involved in the process of placing offers and requests for LRs, matching offers with requests and booking of LRs. During these transactions the system deals with issues such as user authentication and transaction supervision; in the future maybe even billing will be handled. The delivery management engine arranges for the delivery of LRs by granting access rights. Since UNIVERSAL does not offer content storage itself, delivery systems are connected to the brokerage system. A thin generic interface layer provides communication functionality across this connection, e.g. by providing authentication and authorization services, delivery negotiation and delivery supervision. UNVERSAL will offer a fully implemented delivery interface to the following restricted set of delivery systems, but is also open to others by providing a generic delivery interface: • Apache web server (asynchronous packaged content) • Hyperwave’s e-learning suite (learning management system), • RealNetwork’s Realserver (asynchronous streaming content), • Isabel (synchronous collaboration tool and video conferencing system) The user profile engine is in charge of user administration issues such as user registration and cancellation. The user engine provides services to other engines (especially the LR metadata engine) in order to maintain user profiles. Enhanced usage logging allows UNIVERSAL to provide personalized access to its LR repository. Finally, the administration engine maintains all logging data and tracks changes in the UNIVERSAL repository. In addition, the administration engine provides platform assessment services.
3.
MODELING AN E-MARKET-PLACE OF LR
UNIVERSAL can be viewed as a medium which enables communication about artefacts between human and artificial agents [see 4]. The necessary prerequisite for communication is a common language and understanding [5]. Defining a common syntax and semantics is, therefore, a crucial activity in the design of an e-market-place. Learning resources and other artefacts must be described using structured metadata in order to enable an effective query of the repository [6]. The structured metadata provides a knowledge base that can be used to facilitate an open interface for various standards issued by organizations such as IEEE, IMS, Dublin Core, ADL, and AICC. On the e-market-place LRs are traded by offers comprising the components shown in Figure 2. Each
component represents a type of artefact which can be glued together with others. All artefacts are modelled within RDF [7].
Figure 2: Components of a LR Offer 3.1. Modelling Learning Information
Resources
and
Related
The central artefacts of UNIVERSAL are learning resources. This component contains attributes describing the learning resource and providing hints on its usage. The general attributes are divided into two levels depending on their importance. Most of these attributes are equivalent to the attributes suggested by the IEEE LOM standard [10] and IMS [11]. However, some modifications to these suggestions, as well as more in-depth definitions, were necessary in order to serve the requirements of the platform. A learning resource in this context is an abstract definition which can be associated with more than one physical resource specified by the delivery system it requires. Annotations are used for storing reviewing data provided by registered users. Taxonomies provide schemas for the organization of the UNIVERSAL LR directory [see 12]. An LR metadata instance can refer to multiple categories within a taxonomy. LRs can be classified multiply using different taxonomies. By treating classifications as components, taxonomy interrelations can be expressed more easily (e.g. linkage between taxonomies in different languages). 3.2. Modelling Agents The metadata on ‘agent’ comprises information about human or software agents. Universal supports role types for Learners, Provider, Consumer, Evaluators, and Local Registration Authorities [for detailed discussion, see 4]. The metadata on a human agent is based on the widely used vCard [13] standard. The graph in Figure 3 illustrates an RDF instance of an human agent. One important part of a platform framework that trades with digital goods is the Digital Rights
Management. This provides services that secure digital content, and manage the use of the secured content in accordance with the rights and interests of all parties in digital commerce. The UNIVERSAL platform will allow assignment, to every learning resource, of a set of rights to grant usage privileges to an agent. This set of rights is based on the developing industry standards of right(s) expression languages: The “Extensible Rights Markup Language” (XrML) [14] defined by Xerox and the “Open Digital Rights Language” ODRL [15] developed by Ianella. 1090
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method of authentication and authentication details; and • contact addresses of agents responsible for the delivery system. With this data, the UNIVERSAL brokerage platform can access the delivery system and negotiate the terms of the actual delivery, preparing the way for actual consumption of the LR by a potential platform user. When it comes to LR delivery, the functionality of the delivery system interface guarantees fulfillment of the offer terms specified in the Rights Expression Language and in scheduling.
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Gustaf Neumann vCard: FN
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http://wwwi.wu-wien.ac.at/ people/Neumann.html vCard: Title vCard:N Chair of Information Systems
vCard:Prefix Prof. Dr.
vCard:Family vCard:Given Neumann Gustaf
Figure 3: RDF Instance of Human Agent The Rights Management System contains: Rights Expression Language, Rights Messaging Protocol and Policy Enforcement. The Rights Expression Language specifies user privileges regarding LRs; the Rights Messaging Protocol provides means to exchange rights expressions among agents. The Policy Enforcement ensures the application of the policies implied by the digital rights expressions. 3.3. Modelling Offers and Related Information To create an offer scheduling; information can be added to specify the exact delivery dates and the delivery system. Delivery system metadata contains information on how to access the LR offered. The following elements are encapsulated within the delivery system description: • name of the delivery system; • URL of the delivery systems’ UNIVERSAL interface layer;
IMPLEMENTATION OF THE RDF APPROACH
Formal presentation of the artefacts is modeled by means of the Resource Description Framework (RDF) [7]. The foundation of RDF is a general model to represent the named properties and property values of resources. The Extensible Markup Language (XML) [8] is used to encode the RDF-modeled learning resource metadata on the UNIVERSAL platform. The integration of a wide variety of different learning asset delivery systems, most probably based on heterogeneous description schemes, demands a metadata approach which is both highly flexible and essentially distributed in nature. By using XML, metadata descriptions can easily be understood, reused or transformed by using standard tools (see Figure 4). RDF provides the framework to describe metadata assets in a flexible way, using description elements from a variety of different description schemas. The RDF approach further ensures that metadata can be accessed and searched in a distributed manner. The UNIVERSAL brokerage service holds learning resource offer descriptions as XML:RDF instances in a metadata repository, which is built as file store as well as an RDF triple database. Consequently accessing UNIVERSAL metadata can be accomplished in a fast and standardized manner, and metadata search can be carried out very flexibly. The RDF triple approach is further used for entering metadata in user interface forms. Figure 4 illustrates the "metadata lifecycle" for the process of learning resource metadata provision. Metadata on learning resources can be entered into the platform in two different ways. On the one hand, providers can directly enter data via the user interface. On the other, the platform allows direct import of metadata from an external XML or XML:RDF instance. In this case metadata is mapped to a triple representation and stored in the triple database. Alternatively, a foreign metadata instances can be stored as an XML:RDF instance which is compatible with the UNIVERSAL metadata format.
UNIVERSAL XML:RDF Repository User enters learning resource meta data
User Interface
RDF Model Generator Triple Generator
RDF Model Serialization
RDF Model UNIVERSAL Knowledge Base
XML:RDF File XML:RDF
EXPORT FORMATS
UI Datamodel
Triple Database
"foreign" datamodel
Triple Generator
External XML:RDF File
Metadata is provided from external system
Model Generator
XML File
UNIVERSAL Catalogue
Catalogue Generator
XHTML File
Figure 4: Metadata Lifecycle for the Process of Metadata Provision This feature facilitates the open exchange of learning resource descriptions from third party delivery systems. It allows learning management systems to search the repository via an RDF query protocol. The above process can be similarly mapped to the other types of metadata used in the platform. Data from the triple database can be mapped onto an XML:RDF instance at any time, and vice versa.
5.
CONCLUSION
This paper has discussed modeling components of an electronic market of learning resources. The XML:RDF approach was chosen in order to ensure openness and flexibility in modeling artefacts such as learning resources, agents, rights, taxonomy, annotations, scheduling data and delivery systems. Openness is required in order to enable efficient data interchange among various systems, such as those mentioned above or student modeling agents (e.g. the student assistant agent of the MADE system [9]). On the one hand, the XML:RDF files can be parsed easily by third party systems; on the other, RDF triples (i.e. sets of subject, predicate, object) provide an effective tool for searching. UNIVERSAL is currently available in prototype form. However, new challenges are already arising, such as providing generally accepted taxonomies, multilanguage support and establishing quality assurance mechanisms. At the time of writing, trials are taking place with professors outside the development team.
6.
REFERENCES
[1] M. Hämäläinen, A. B. Whinston, and S. Vishik, “Electronic Markets for Learning: Education Brokerage on the Internet,” Communications of the ACM, vol. 39, pp. 51-58, 1996. [2] D. Tsichritzis, “Reengineering the University,” Communications of the ACM, vol. 42, pp. 93-100, 1999.
[3] P. Meier and B. Simon, “Reengineering Undergraduate Teaching by Introducing Internet-based Learning Information Systems,” in Proceedings of the 8th European Conference on Information Systems, vol. 1439-1444, Vienna: Springer, 2000. [4] S. Guth, G. Neumann, and B. Simon, “UNIVERSAL - Design Spaces for Learning Media,” in Proceedings of the 34th Hawaii International Conference on System Sciences, Maui (USA), Maui, USA: IEEE, 2001. [5] K. Stanoevska-Slabeva and B. F. Schmid, “Requirements Analysis for Community Supporting Platforms Based on the Media Reference Model,” International Journal of Electronic Markets, vol. 10, pp. 250-257, 2000. [6] F. Arcelli and M. De Santo, “An Agent based Internet Infrastructure for Learning Commerce,” in Proceedings of the 33rd Hawaii International Conference on System Sciences 2000, O.A., Ed. Maui, 2000. [7] D. Brickley and R. V. Guha, Resource Description Framework (RDF) Model and Syntax Specification: W3C Recommendation: REC-rdf-syntax-19990222, 1999. [8] T. Bray, J. Paoli, and C. M. Sperger-McQueen, Extensible Markup Language (XML): W3C Recommendation: REC-xml19980210, February 1998. [9] S.-G. Han, J.-B. Park, J.-E. Jung, and G.-S. Jo, “Intelligent Gathering of Contents on Distance Education using Mobile Agents,” in Proceedings of the International Conference on Electronic Commerce 2000, Seoul, Korea: 2000, pp. 267-273. [10] “IEEE Learning Technology Standards Committee (LTSC) Learning Object Metadata - Draft Document v3.8” http://ltsc.ieee.org/doc/wg12/LOM3.8.html, 1999. [11] T. Anderson, D. McArthur, S. Griffin, and T. Wason, IMS Meta-data Best Practice and Implementation Guide: Educause, 1999. [12] B. Simon and G. Vrabic, “Learning Resource Catalogue Design of the UNIVERSAL Brokerage Platform,” in Proceedings of ED-MEDIA 2001, C. Montgomerie and J. Viteli, Eds. Tampere, Finnland: AACE, 2001, forthcoming. [13] F. Dawson and T. Howes, vCard MIME Directory Profile. The Internet Society: http://andrew2.andrew.cmu.edu/rfc/rfc2426.html, 1998. [14] X. Wang, Extensible rigths Markup Language (XrML): http://www.xrml.org, 2000. [15] R. Iannella, “Open Digital Right Languages (ODRL),” W3C Workshop on Digital Rights Management, 2001.
