Chapter 3 STRUCTURE 85

3.1 The Evolution of Data Models 86

3.1.1 CODASYL 87


3.1.2 Hierarchical Databases 89

3.1.3 Relational Databases 89

3.1.4 Navigational Architectures 95

3.2 Conceptual Modeling 100

3.2.1 The Entity Relationship Model 101

3.2.2 Asset-Oriented Modeling (AOM) 108

3.2.3 A Document-Centered Step-by-Step Approach 113

3.2.4 Smash the Enterprise Data Model? 132

3.2.5 Best Practices 133

3.3 The Resource Description Framework and Conceptual Modeling 134

3.3.1 RDF Basics 135

3) RDF - what is it and why is it needed? What is semantic data? Describing relationships in data; markup for metadata; semantic markup for web pages - inline, or in referenced databases - SI site example; power of shared standard - network effects of rdf described data that semweb is built on; will it succeed? How is it being developed? The community of standards development at W3C.

Invited Speaker - Eric Miller, head of W3C Semantic Web Activities Area

Reading Assignments:

Michael. Daconta, L. Obrst, K. Smith, The Semantic Web: A Guide to the Future of XML, Web Services, and Knowledge Management, Wiley & Sons, 2003, chapter 5

Shelley Powers, Practical RDF: Solving Problems with the Resource Description Framework, O'Reilly & Associates, 2003, chapters 1-7, 10

Frank Manola, Eric Miller, RDF Primer, January 23, 2003

RDF online tutorials:

RDF Tutorial - Part 1: Basic Syntax and Containers

Tutorial for RDF and RDFS

RDF Tutorial - Pierre-Antione Champin


4) Examples of the use of RDF. Spending more time with fundamentals of semantic markup, and then starting to put what we have learned into practice. Some quick examples to show the value of this approach. Why do I want machines reading my pages? Friend of a Friend, creating machine readable home pages. Semantic blogging, adding semantic info to items shared over the blog channels, allowing navigation and search along semantic rather than simply chronological or serendipitous connections. Personal Information management using RDF - haystack project: a "universal Information client". The School of Information semantic markup project, intro to using TAP at SI.
Demos and discussions with developer(s).

Invited Speakers: tbd (from MIT haystack team)

Reading Assignments:

Semantic Blogging for Bibliography Management

Dennis Quan, David Huynh, and David R. Karger. Haystack: A Platform for Authoring End User Semantic Web Applications to appear in ISWC 2003.

XML Watch: Finding Friends with XML and RDF: The Friend-of-a-Friend vocabulary can make it easier to manage online communities, Edd Dumbill, June 1, 2002



3.3.2 From ERM to RDF 139

3.3.3 Advanced Modeling Techniques 143

3.3.4 Reification 150

3.3.5 RDF Schema 152

3.3.6 Reasoning with RDF 156

3.3.7 Best Practices 158

3.4 A U for an X 158

3.4.1 XML Modeling with UML 158

3.4.2 XMI: Exchange Format for Model Data 163