An Open Framework for Integrated Qualification Management Portals

Similar documents
PROCESS USE CASES: USE CASES IDENTIFICATION

CREATING SHARABLE LEARNING OBJECTS FROM EXISTING DIGITAL COURSE CONTENT

Group A Lecture 1. Future suite of learning resources. How will these be created?

Chamilo 2.0: A Second Generation Open Source E-learning and Collaboration Platform

Specification of the Verity Learning Companion and Self-Assessment Tool

USER ADAPTATION IN E-LEARNING ENVIRONMENTS

Applying Information Technology in Education: Two Applications on the Web

An Industrial Technologist s Core Knowledge: Web-based Strategy for Defining Our Discipline

Online Marking of Essay-type Assignments

AGENDA LEARNING THEORIES LEARNING THEORIES. Advanced Learning Theories 2/22/2016

Diploma in Library and Information Science (Part-Time) - SH220

Modeling user preferences and norms in context-aware systems

School Inspection in Hesse/Germany

Knowledge-Based - Systems

Unit 7 Data analysis and design

CWIS 23,3. Nikolaos Avouris Human Computer Interaction Group, University of Patras, Patras, Greece

On the Open Access Strategy of the Max Planck Society

ECE-492 SENIOR ADVANCED DESIGN PROJECT

1 Use complex features of a word processing application to a given brief. 2 Create a complex document. 3 Collaborate on a complex document.

WP 2: Project Quality Assurance. Quality Manual

AQUA: An Ontology-Driven Question Answering System

PROGRAMME SPECIFICATION

On Human Computer Interaction, HCI. Dr. Saif al Zahir Electrical and Computer Engineering Department UBC

Tailoring i EW-MFA (Economy-Wide Material Flow Accounting/Analysis) information and indicators

P. Belsis, C. Sgouropoulou, K. Sfikas, G. Pantziou, C. Skourlas, J. Varnas

AUTHORING E-LEARNING CONTENT TRENDS AND SOLUTIONS

Higher Education Review (Embedded Colleges) of Navitas UK Holdings Ltd. Hertfordshire International College

EDITORIAL: ICT SUPPORT FOR KNOWLEDGE MANAGEMENT IN CONSTRUCTION

Introduction of Open-Source e-learning Environment and Resources: A Novel Approach for Secondary Schools in Tanzania

Designing e-learning materials with learning objects

Specification and Evaluation of Machine Translation Toy Systems - Criteria for laboratory assignments

Computerized Adaptive Psychological Testing A Personalisation Perspective

A GENERIC SPLIT PROCESS MODEL FOR ASSET MANAGEMENT DECISION-MAKING

IBM Software Group. Mastering Requirements Management with Use Cases Module 6: Define the System

Bluetooth mlearning Applications for the Classroom of the Future

Evaluation of Usage Patterns for Web-based Educational Systems using Web Mining

Evaluation of Usage Patterns for Web-based Educational Systems using Web Mining

Referencing the Danish Qualifications Framework for Lifelong Learning to the European Qualifications Framework

Running Head: STUDENT CENTRIC INTEGRATED TECHNOLOGY

Memorandum. COMPNET memo. Introduction. References.

GALICIAN TEACHERS PERCEPTIONS ON THE USABILITY AND USEFULNESS OF THE ODS PORTAL

Requirements-Gathering Collaborative Networks in Distributed Software Projects

Visual CP Representation of Knowledge

VOCATIONAL QUALIFICATION IN YOUTH AND LEISURE INSTRUCTION 2009

Nearing Completion of Prototype 1: Discovery

Mexico (CONAFE) Dialogue and Discover Model, from the Community Courses Program

Concept Acquisition Without Representation William Dylan Sabo

Statewide Strategic Plan for e-learning in California s Child Welfare Training System

Scientific information management policies and information literacy schemes in Greek higher education institutions and libraries

BPS Information and Digital Literacy Goals

Android App Development for Beginners

On-Line Data Analytics

Automating the E-learning Personalization

A Context-Driven Use Case Creation Process for Specifying Automotive Driver Assistance Systems

UCEAS: User-centred Evaluations of Adaptive Systems

Learning Methods for Fuzzy Systems

Emma Kushtina ODL organisation system analysis. Szczecin University of Technology

Pragmatic Use Case Writing

State of play of EQF implementation in Montenegro Zora Bogicevic, Ministry of Education Rajko Kosovic, VET Center

Three Strategies for Open Source Deployment: Substitution, Innovation, and Knowledge Reuse

A Didactics-Aware Approach to Management of Learning Scenarios in E-Learning Systems

Motivation to e-learn within organizational settings: What is it and how could it be measured?

DIGITAL GAMING & INTERACTIVE MEDIA BACHELOR S DEGREE. Junior Year. Summer (Bridge Quarter) Fall Winter Spring GAME Credits.

Modelling interaction during small-group synchronous problem-solving activities: The Synergo approach.

An Introduction to the Minimalist Program

Using Moodle in ESOL Writing Classes

Introduction to Modeling and Simulation. Conceptual Modeling. OSMAN BALCI Professor

GACE Computer Science Assessment Test at a Glance

The Moodle and joule 2 Teacher Toolkit

EOSC Governance Development Forum 4 May 2017 Per Öster

Knowledge Management: Why Learning from the Past Is Not Enough!

Library Consortia: Advantages and Disadvantages

Activities, Exercises, Assignments Copyright 2009 Cem Kaner 1

Quality in University Lifelong Learning (ULLL) and the Bologna process

The role of virtual laboratories in education

Global MBA Master of Business Administration (MBA)

COURSE LISTING. Courses Listed. Training for Cloud with SAP SuccessFactors in Integration. 23 November 2017 (08:13 GMT) Beginner.

Experience and Innovation Factory: Adaptation of an Experience Factory Model for a Research and Development Laboratory

Efficient Use of Space Over Time Deployment of the MoreSpace Tool

Operational Knowledge Management: a way to manage competence

Community-oriented Course Authoring to Support Topic-based Student Modeling

Abstractions and the Brain

Programme Specification

Supporting flexible collaborative distance learning in the CURE platform

The recognition, evaluation and accreditation of European Postgraduate Programmes.

Ministry of Education, Republic of Palau Executive Summary

Summary results (year 1-3)

November 17, 2017 ARIZONA STATE UNIVERSITY. ADDENDUM 3 RFP Digital Integrated Enrollment Support for Students

M55205-Mastering Microsoft Project 2016

DYNAMIC ADAPTIVE HYPERMEDIA SYSTEMS FOR E-LEARNING

Innovating Toward a Vibrant Learning Ecosystem:

Guidelines for Mobilitas Pluss postdoctoral grant applications

Every curriculum policy starts from this policy and expands the detail in relation to the specific requirements of each policy s field.

Designing a Rubric to Assess the Modelling Phase of Student Design Projects in Upper Year Engineering Courses

A European inventory on validation of non-formal and informal learning

Evolution of Symbolisation in Chimpanzees and Neural Nets

A student diagnosing and evaluation system for laboratory-based academic exercises

The MEANING Multilingual Central Repository

MASTER OF SCIENCE (M.S.) MAJOR IN COMPUTER SCIENCE

THE DEPARTMENT OF DEFENSE HIGH LEVEL ARCHITECTURE. Richard M. Fujimoto

Transcription:

An Open Framework for Integrated Qualification Management Portals Michael Fuchs, Claudio Muscogiuri, Claudia Niederée, Matthias Hemmje FhG IPSI D-64293 Darmstadt, Germany {fuchs,musco,niederee,hemmje}@ipsi.fhg.de Abstract Systematic and individual qualification improvement in a professional context is a challenging task, which is based on a complex knowledge supply chain. Human as well as virtual actors contribute to this supply chain and have to be supported by adequate system services. The authors believe that a qualification management portal that integrates support for all qualification-related activities like course production, content provision, teaching, and learning, into an open system enables the flexibility, responsiveness, and community-orientation that is necessary for modern qualification support. The coupling of the involved processes and roles enables synergies and innovative communication opportunities. A flexible, extensible, and standard-compliant framework for such integrated qualification management portals has been developed in the equalification project. By integrating user-friendly and task-oriented application authoring tools for qualification portal design and evolution into the Web application itself, users are empowered to act as application co-designers. 1. Introduction The information society imposes challenging requirements towards learning behavior but also provides exciting new learning opportunities enabled by using computer- and Web-based technologies for teaching and learning. Learning is no longer linked to special times, places or phases in the lifetime [1]. Learning becomes a permanent qualification process where learners acquire new skills and knowledge according to their preferences and the needs of their personal (working) environments. Successful qualification management (QM) depends on the entire knowledge supply chain including - provision and management of focused, high-quality training material, - qualification goal planning, - skill-aware selection of learning content, and - effective step-by-step learning support. Thus, QM as well as its system support is a challenging task that involves several actors in different roles. Furthermore, QM is complicated by the accelerated innovation cycles in many application domains. For this purpose mediation between qualification needs and goals on the one side and the available learning content on the other side is crucial. In the equalification project four complementing mediator roles supporting the qualification process have been identified: qualification consultant, portal provider, domain manager, and tutor. An integrated system approach as it is propagated in the equalification project enables integration synergies like inter-role communication and intelligent support of mediator roles. The customizable QM framework developed in the equalification project integrates flexible system support for all phases of the QM process and exploits the resulting synergies for the realization of an improved, customized QM. Flexibility is achieved by combining three types of components: A) Modular, task-specific packages for the support of the different tasks and roles in the QM process like shared workspaces for tutors and learners, e-learning communication and cooperation support, semiautomatic qualification consulting, SCORM 1 compliant user tracking [2], workflow support for cooperative WBT 2 authoring, etc., B) a set of task-specific authoring tools, for the set up and management of typical business objects and processes in the qualification application domain, and C) a set of generic Web application authoring tools for system set up, customization and evolution. The authoring tools empower special users like the portal provider to take an active part in system customization and evolution as well as in the support of new roles. We believe, that a wide range of evolutionary changes can be supported in a (QM) Web application itself. For this purpose meta-design [3] is applied, i.e., Web applications provide integrated support for participating in their own design process. To achieve this goal, Web application authoring support is necessary, that has to be at the same time powerful and user-friendly; this kind of support empowers special users of the Web application, the power users [4], not only to use the application but also to adapt it to changing requirements. In our approach the combination of task-specific and generic Web 1 SCORM (= Sharable Content Object Reference Model) is a standard for the structuring, description, and handling of learning objects. 2 WBT = Web Based Training

application authoring tools aims at providing such metadesign support. The rest of this paper is structured as follows: The key roles involved in the QM process and the synergies achieved by integrating support for all parts of the QM knowledge supply chain into one system are discussed in section 2. Section 3 focuses on our approach to a flexible framework for integrated QM portal implementation and introduces the concepts underlying the authoring tools. The paper concludes with a discussion of related work and plans for future research in sections 4 and 5. Portal Developer Course Manager Administrator Domain Manager System User Tutor Figure 1: Roles in the QM process 2. Roles in the Qualification Management Process Human and non-human actors in various roles are involved in the QM process. The two basic user roles learner and WBT author, that form the two end points of the knowledge supply chain, are supplemented by additional roles acting as mediators in the process. 2.1 Mediator Roles Portal Provider Qualification Consultant In addition to the QM portal provider, the domain manager, and the tutor, the equalification framework introduces the qualification consultant as an important mediator role in the QM process (see Figure 1). All these roles contribute to the mediation between the qualification needs of learners and the available WBT contents: - QM portal providers act as mediators between the WBTs and the learner community as potential clients. They make the WBTs available, control access and offer community services. - QM domain managers support the portal providers in their mediation task by managing the knowledge domains and organizing the available WBTs, learner skills and qualification goals into these domains. - Qualification consultants support a specific learner in course selection and qualification planning mediating between the available content and the qualification goals and preconditions of the learner. Consulting roles can be performed by humans with system support or fully automatic based on coded rules. Role Guest Mediator Learner WBT Author Editor Topic Autho r Designer - Tutors mediate between a specific WBT course and an associated group of learners (virtual classroom). They support learners in the knowledge acquisition process. The roles can be further refined. The WBT author for example is just one of a group of different author types involved in the WBT production process (see Figure 1). 2.2 Integration Synergies Various task-specific system services are necessary to support the variety of roles in the QM process. Separate role-specific tools can be used for this purpose, like authoring tools for the production of the WBTs, a virtual classroom tool for the learning process, etc. Instead of providing separate tools, the equalification project propagates an integrated, but extensible QM portal, that incorporates system support for the different roles fostering the following integration synergies: - The coexistence of all roles in one context introduces new opportunities for inter-role communication. As an example, WBT quality and focus can be improved by inter-role communication between learners and WBT authors enabling different forms of feedback. - On the semantic level the sharing of a QM core model and a common knowledge infrastructure, especially the central knowledge domain network, contributes to a common domain view for all involved partners. This joint understanding has positive effects on learning, qualification planning, consistent course production, and (inter-role) communication. Furthermore, it fosters the provision of consistent intelligent assistance. - The shared use of a service infrastructure like, e.g., communication components, lowers the boundaries between roles. This facilitates a switch between roles and enables new forms of learning and course creation [5], e.g., by incorporating learners into the course production process [6]. - If all engaged WBT authors rely on the authoring support provided by the integrated system this contributes to the homogeneity and consistency of the course material. This effect is intensified by the use of (uniform) templates in WBT production. The QM process, the involved roles, and the underlying knowledge supply chain vary considerably in different QM contexts like corporate and public universities, schools, etc. So flexibility and extensible multi-role support are important design issues for a QM framework. 3. An Open Framework for Integrated Qualification Management Portals An open framework for integrated QM portals has been developed in the equalification project 3 based on an extensible component architecture that can be easily 3 Further project information can be found at http://ipsi.fraunhofer.de/delite/projects/equalification 2

customized to meet the requirements of specific QM portal providers. Flexibility is achieved by supporting three types of components: A) Modular, task-specific packages for the support of the different tasks and roles in the QM process; B) Task-specific authoring tools, for the setup and management of typical business objects and processes in the application domain; C) Generic Web application authoring tools for system set up, customization and evolution. The authoring tools empower special users to take an active part in QM system customization and evolution. 3.1 User Empowerment We believe, that a wide range of evolutionary changes can be supported in the Web-based QM system itself by providing adaptation support mechanisms. For this purpose, meta-design [3] for Web applications is required. To achieve this goal, our framework provides powerful Web application authoring support for power users [4], empowering them to adapt the system to changing requirements. For real user empowerment we are interested in system modification that goes beyond user interface customization. Users should be enabled to manipulate system functionalities (in an operational system) to the underlying QM business process. Such modifications are normally reserved to skilled software developers. Since the power users are members of the application domain, we may not assume programming skills. The use of task specific design support [4] instead of general programming languages provides a user-friendly working environment for the development task. It has to be noted here, that we do not expect power users to develop an entire QM solution from scratch on their own. The focus is on small incremental changes and adaptations in an operational system. 3.2 The Authoring Tools Conceptual Framework Online user UI-Control user interface object Control-Control user interface object Control-Data control object data object control object Figure 2: Authoring tool objects It is the aim of our approach to provide a framework for adequate task-specific design support which is required for the new kind of co-designers and developers in system customization and evolution. An extended analysis of the designers activities and their tools in [7] confirms that design communities gradually construct their domain by defining domain objects, creating and evolving multiple representation for them, and establishing complex relationships between objects through their representation. Within the context of the equalification framework this domain construction process is performed on a particular domain that is a complex syntactic and semantic coalescence of objects and relationships between them. FORM MANAGER(Composer) CONTROL MANAGER Publishing Tools FIELD MANAGER MENU MANAGER web publishing model Central Model Repository presentation control constraint data action COURSE CONTENT MANAGER Task specific Tools COURSE BOOKING MANAGER Figure 3: Authoring tool environment The development and evolution of an integrated QM solution requires a coupling of entities from at least two different domains: - the domain of Web application development; - the application domain, which includes QM business objects, relationships and business processes. A systematic approach to their flexible coupling starts with the modeling of the domains. In a second step, a model that systematically specifies the process of between objects of the Web application user interface to business objects or business process subtasks of the QM application domain has to be enabled. The validity of such an approach is confirmed by analyzing UI design best practice [8], which follows the model-based UI development paradigm [9]. According to software engineering best practice, design modeling elements can be stereotyped in three basic kinds of objects [10]. Boundary objects model the interaction between actors and the system. Control objects handle the main tasks and control flows representing the dynamics of a system. Entity objects model the information stored by the system and its associated behavior. Specializing this approach for our conceptual framework, the authoring environment allows power users to (implicitly) define user interface objects, which are a special type of boundary objects, control objects representing specific client and server logic and data objects for the information stored by the system. A key activity in the authoring tools is the definition of s between different types of objects (see Figure 2). Figure 3 illustrates the authoring tools conceptual framework. In the framework task-specific authoring tools (task-specific tools) are used for the set up and management of task-specific objects and s in the Central Model Repository (CMR) and generic Web application authoring tools (publishing tools) are used for the definition and set up of components for the Web publishing 3

for $course in (/eqf/courses/course[domain_id=1]) return (for $auhor in (/eqf/authors/author[id=$course/author_id]) return (for $domain in (/eqf/domains/domain/id=$course/domain_id) return ($course/id,$course/title,$course/price,$author/name,$domain/name))) Figure 4: Course booking control model which is the complete definition of the Web application implementing the integrated QM portal at run time. For maximum client side compatibility a form based approach has been chosen for the framework. Following the model-view-controller approach for flexible user interface design [11], form-based user interfaces are split into form layout specification (view), form dialog control (control), and the underlying form data schema (model) as it is proposed in [12]. Figure 5: A course booking In using the task-specific tools the power users manage domain tasks to be applied on specific domain entities by implicitly creating control, data and s that are stored in the CMR. For instance, the course booking manager, which is one of the task-specific tools in the QM context, enables the portal provider to define properties for the course booking service like prices as well as special constraints or business logic to be applied. A resulting is shown in Figure 4 including the definition for a control object named course_catalogue_booking, which implements the definition for a specific online course catalogue. The publishing tools enable power users to compose the Web publishing model (see Figure 3) by defining, managing, and using - control object templates (e.g. homogenous collection, generic_submit) storedinthecmr, - s between s (i.e. control, UI, constraints, action objects) defined using the taskspecific tools, - UI object templates (e.g. UI_checkbox_list, UI_table_list) stored in the CMR, - constraint and action objects definition that complete course_catalogue_booking control Figure 6: Mapping object generic_selection_list control <output>course Catalogue for Domain IT</output> <repeat ref="/eqf"> <group ref="courses" <output ref="course/title"> <output ref="../author[id=course/author_id]"> <output ref="course/price"> </group> <selectone ref="transactions/transaction" selectui="checkbox"/> <item> <value ref="id"/></item> </selectone> </repeat> UI_checkbox_list object specific UI logic stored in the CMR The resulting object and definitions are stored in the CMR. Once a course catalogue has been defined using the booking manager as described, a power user probably wants to offer an on-line booking service for such a catalogue; therefore he/she wants presumably to create a Web page like the one shown in Figure 5. In this case the power user will employ the publishing tools for setting up the catalogue information to be published as a list, where each entry in this list is associated with a checkbox implementing the booking logic; in doing this a object is created (see Figure 6). Other objects will be implicitly referenced or created, like a generic_submit object and UI_table_list templates. All the information stored in the CMR is composed for defining the Web page model (part of the Web publishing model, together with the definition of other required components, such as navigation/browsing components). Figure 7 shows how the Web publishing model is applied for implementing the run time behavior. The server side pre-compiler component reads the Web publishing model, compiles the required components and produces a UI description written in an intermediate description language. In the equalification framework this is an XForms definition compliant language [12], which is user agent independent. In the UI description all the s are resolved to binding Client Specific XForms Processor Pre-Compiler web puplishing model Figure 7: Framework run time mechanisms between UI components and application data. The agent-specific processor gets the resulting UI description and generates the user interface instance specific for the user agent, which sent the request. 4. Related Work XForm compliant UI description XHTML Processor Data Translater/Processor Application Data WAP Processor The implemented approach to task-specific design support was influenced by the idea of DODEs (Domainoriented Design Environments) [13]. Essentially, DODE includes a construction kit providing a palette of domain building blocks, an argumentative support, a catalogue of pre-stored designs, a specification component supporting d 4

the interaction among stakeholder, and a simulation component (for what-if games). It is our aim to build a design environment that is not restricted to one application domain but usable for the entire class of information, knowledge, and content management solutions with community support in different application domains like trade fair business, e-learning, etc. For this purpose, we plan to generalize the DODE approach by factoring domain-specific knowledge into a domain model and developing a meta-model for the interaction of the domain model with the components of the design environment. Our implementation uses the XForms specification from the W3C, which currently is available as a Working Draft [12]. This specification relies on several other XML related standards like XML Schema [14] and XPath [15]. As a basis for the definition of s in the Publishing Tools we rely on existing specifications for s between different types of models e.g. between the Relational Model and XML Schema or between an object-oriented schema and an XML Schema (see for example [16]). 5. Conclusions and Future Work In this paper we presented a conceptual framework for the provision of general as well as task-specific authoring tools as an integral part of an integrated QM system. The authoring tools that have been implemented for a formbased environment empower the user to individually set up and adapt the system to the underlying QM process. Since the presented framework is work in progress there are different types of future contributions planned. The implemented Publishing Tool is restricted to direct database s. Currently we are working on the integration of other types of s. On the one hand intermediate business objects that may themselves be mapped to the database objects as one possible target. On the other hand this is the to the task specific packages that have to be connected to the Web application model or in more detail to the Web pages produced by the Publishing Tool. Furthermore, we investigate on increasing the user comfort of the Publishing Tool pursuing our primary aim of real user empowerment. Currently we mainly consider UI boundary objects. In future we plan to integrate other kinds of boundary objects relevant for a QM system. An important type of boundary objects are connections to other systems in the context of the QM system. This type of binding contribute to better integrating the learning with the working environment helping to overcome the dichotomy between a place and time to acquire knowledge (school) and a place and time to apply knowledge (the workplace) [1]. For the evolution of entire Web applications we need authoring tools enabling the composition of several forms into a navigation map. User-friendly tools for this purpose are a further focus of our current research. Acknowledgements The support of the equalification project through the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF), Germany, is acknowledged. We are also grateful for the work carried out by the other partners in the equalification project. 6. References [1] Fisher G., Lifelong Learning - More Than Training, International Journal of Continuing Engineering Education and Life- Long Learning, Special Issue on "Intelligent Systems/Tools In Training And Life-Long Learning", 1999. [2] Advanced Distributed Learning Initiative (ADLnet), Sharable Content Object Reference Model (SCORM), October 2001. http://www.adlnet.org/ [3] Fisher G., Social Creativity, Symmetry of Ignorance and Meta-Design, Knowledge-Based Systems Journal, 13(7-8): 527-537, 2000. [4] Nardi B.A., A Small Matter of Programming, MIT Press, Cambridge, Mass., 1993. [5] depaula R., Fischer G., and Ostwald J., Courses as Seeds: Expectations and Realities, In Proceedings of the European Conference on Computer-Supported Collaborative Learning (Euro-CSCL 2001), Maastricht, The Netherlands, March 22-24, 2001, pp 494-501, 2001. [6] Rogoff B., Matsuov E., White C., Models of Teaching and Learning: Participation in a Community of Learners, The Handbook of Education and Human Development -New Models of Learning, Teaching and Schooling, Blackwell, Oxford, pp. 388-414, 1998. [7] Sumner T. R., Designers and their Tools: Computer Support for Domain Construction, University of Colorado at Boulder, Ph.D. Dissertation, Dept. of Computer Science, 1995. [8] Pinheiro da Silva P., User Interface Declarative Models and Development Environments: A Survey, In Proceedings of DSV-IS2000, 2000. [9] Puerta A. R., A Model-based Interface Development Environment, IEEE Software, 14(4):40-47, July/August 1997. [10] The Object Management Group (OMG) Unified Modelling Language (UML), Specification,version 1.4, 2001. http://www.omg.org/technology/documents/formal/uml.htm [11] Krasner G., Pope S., A Cookbook for Using the Model- View-Controller Paradigm in Smalltalk-80, Journal of Object- Oriented Programming, 1(3):6-49, 1988. [12] Dubinko M., Dietl J., Klotz L., Merrick R., Raman T. V., XForms 1.0, W3C Working Draft, 18 January 2002. [13] Fischer G., Domain-Oriented Design Environments, Automated Software Engineering, 1(2): 177-203, 1994. [14] Biron P. V., Malhotra A., XML Schema Part 2: Datatypes, W3C Recommendation, 2. May 2001. http://www.w3.org/tr/xmlschema-2/ [15] Clark J., DeRose S. XML Path Language (XPath) Version 1.0, W3C Recommendation, 16. November 1999. [16] Bourret R., Mapping DTDs to Databases, O Reilly XML.com, May 2001. http://www.xml.com 5