Contents	6
	Foreword	10
	Preface	12
	List of Figures	14
	List of Tables	16
	1 Introduction	18
	1.1 Introductory Examples	21
	1.2 Using Markup to Extract Knowledge	25
	1.3 Applying the Extracted Knowledge	32
	1.4 Structure of the Book	34
	Part I The Model	38
	2 Related Work	40
	2.1 Information Retrieval	41
	2.2 Information Extraction	43
	2.3 Clustering	44
	2.4 Classi.cation	46
	2.5 Web Search Techniques	48
	2.6 Ontologies	51
	2.7 Layout Analysis	53
	2.8 Web Search Studies	53
	2.9 Navigating Concept Hierarchies	55
	2.10 Dialogue Systems	58
	2.11 Usability Issues	59
	2.12 Concluding Remarks on Related Work	60
	3 Data Analysis and Domain Model Construction	62
	3.1 Documents	62
	3.2 Concepts	64
	3.3 A Domain Model Based on Concepts	68
	3.4 Model Structure	70
	3.5 Model Construction	71
	3.6 Using the Model for Query Modi.cation	75
	3.7 Implementational Issues	77
	4 Incorporating Additional Knowledge	80
	4.1 Internal Knowledge	80
	4.2 External Knowledge	84
	5 A Dialogue System for Partially Structured Data	86
	5.1 Dialogue as Movement in Space	87
	5.2 Dialogue Example	88
	5.3 Static	90
	Dynamic Clusters	90
	5.4 Real User Queries	90
	5.5 Properties	92
	5.6 Dialogue	95
	Part II Practical Applications	109
	6 UKSearch - Intelligent Web Search	110
	6.1 Indexing Web Pages	111
	6.2 The UKSearch System	115
	6.3 Sample Domain 1: Essex University	124
	6.4 Sample Domain 2: BBC News	129
	6.5 Implementational Issues	134
	7 UKSearch - Evaluation and Discussion	138
	7.1 Log Analysis	138
	7.2 Investigating Domain Model Relations	142
	7.3 Task-Based Evaluation: Essex University	146
	7.4 Task-Based Evaluation: BBC News	158
	8 YPA - Searching Classified Directories	174
	8.1 System Overview	175
	8.2 Indexing Classi.ed Advertisements	176
	8.3 Dialogue Strategy in the YPA	179
	8.4 Implementational Issues	188
	9 Future Directions and Conclusions	190
	9.1 Towards Evolving Domain Models	190
	9.2 Dialogue Management	193
	9.3 An Outlook on Future Evaluations	194
	9.4 Conclusions	195
	References	198
	Index	210