Table of Contents
Preface v
1 Introduction: Envisioning Semantic Information Spaces 1
Part A Propaedeutics - Organizing, Representing, and Exploring Knowledge
2 Indexing and Knowledge Organization 15
2.1 Knowledge Organization Systems as Indexing Languages 15
2.1.1 Building Elements: Entities and Terms 16
2.1.2 Structural Elements: Intrasystem Relations 21
2.1.3 Result Elements: Indexates 27
2.2 Standards and Frameworks 30
2.2.1 ISO 25964: Thesauri and Interoperability with other Vocabularies 30
2.2.2 Functional Requirements for Subject Authority Data (FRSAD) 31
3 Semantic Technologies for Knowledge Representation 33
3.1 Web-based Representation Languages 33
3.1.1 XML 34
3.1.2 RDF/RDFS 37
3.1.3 OWL 42
3.2 Application-based Representation Languages 49
3.2.1 XTM 50
3.2.2 SKOS 57
4 Information Retrieval and Knowledge Exploration 61
4.1 Information Retrieval Essentials 61
4.1.1 Exact Match Paradigm 62
4.1.2 Partial Match Paradigm 64
4.2 Measuring Effectiveness in Information Retrieval 65
4.3 From Retrieving to Exploring 68
4.3.1 String-based Retrieval Processes 71
4.3.2 Conceptual Retrieval Process 73
4.3.3 Conceptual Exploration Processes 74
4.3.4 Topical Exploration Processes 78
4.4 From Homogeneous to Heterogeneous Information Spaces 80
Part B Status quo - Handling Heterogeneity in Indexing and Retrieval
5 Approaches to Handle Heterogeneity 87
5.1 Citation Pearl Growing 87
5.2 Modeling Multilingual Indexing Languages 89
5.3 Establishing Semantic Interoperability between Indexing Languages 90
5.3.1 Structural Models 91
5.3.2 Mapping Levels 93
5.3.3 Vocabulary Linking Projects 96
6 Problems with Establishing Semantic Interoperability 105
6.1 Conceptual Interoperability between Entities of Indexing Languages 107
6.1.1 Focused and Comprehensive Mapping 108
6.1.2 Conceptual Identity and Semantic Congruence 112
6.2 Equivalent Intersystem Relationships 118
6.2.1 Intersystem Relations Compared to Intrasystem Relations 119
6.2.2 Interoperability and Search Tactics 121
6.2.3 Specified Intersystem Relationships 132
6.2.4 Conceptual Interoperability between Indexing Results 134
6.2.5 Directedness of Intersystem Relationships 137
Part C Vision - Ontology-based Indexing and Retrieval
7 Formalization in Indexing Languages 147
7.1 Introduction and Objectives 147
7.2 Common Characteristics and Differences between Indexing Languages and Formal Knowledge Representation 151
7.3 Prerequisites for an Ontology-based Indexing 156
7.3.1 Semantic Relations and Inferred Document Sets 158
7.3.2 Facets and Inferences 167
8 Typification of Semantic Relations 181
8.1 Inventories of Typed relations 182
8.2 Typed Relations and their Benefit for Indexing and Retrieval 188
8.3 Examples of the Benefit of Typed Relations for the Retrieval Process 194
8.3.1 Example 1: Aspect-oriented Specification of the Generic Hierarchy Relation 194
8.3.2 Example 2: Typed Relations of a Topic Map built from the ASIST Thesaurus 197
8.3.3 Example 3: Degrees of Determinacy 213
9 Inferences in Retrieval Processes 215
9.1 Inferences of Level 1 216
9.1.1 Hierarchical Relationships 216
9.1.2 Associative Relationships 227
9.1.3 Typification of the Synonymy / Equivalence Relationship 218
9.2 Inferences of Level 2 and of Higher Levels, Transitivity 222
9.2.1 Hierarchical Relationships 223
9.2.2 Unspecific Associative Relationships 226
9.2.3 Typification of Associative Relationships 229
9.3 Inferences by Combining Different Types of Relationships 231
9.3.1 Synonymy Relation with Hierarchical Relationships 231
9.3.2 Chronological Relation with Hierarchical Relationships 232
9.3.3 Transitions from Associative Relationships to a Hierarchical Structure 232
9.3.4 Transitions from a Hierarchical Structure to Associative Relationships 233
9.3.5 Transitivity for Combinations of Typed Associative Relationships 235
10 Semantic Interoperability and Inferences 237
10.1 Conditions for Entity-based Interoperability 237
10.2 Models of Semantic Interoperability 244
10.2.1 Ontological Spine and Satellite Ontologies 244
10.2.2 Degrees of Determinacy and Interoperability 250
10.2.3 Entity-based Interoperability and Facets 252
10.3 Perspective: Ontology-based Indexing and Retrieval 254
11 Remaining Research Questions 259
11.1 Questions of Modeling 259
11.2 Questions of Procedure 260
11.3 Questions of Technology and Implementation 262
Part D Appendices
Systematic Glossary 265
Abbreviations 271
List of figures 273
List of tables 277
References 279
Index 289
