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Footnote

The next chapter introduces resource description framework (RDF) and RDF schema (RDFS). Unlike XML, RDF provides a foundation for expressing the semantics of dada: it is a standard dada model for machine-processable semantics. Resource description framework schema offers a number of modeling primitives for organizing RDF vocabularies in typed hierarchies. In addition to RDF and RDFS, a query language for RDF, i.e. RQL. is introduced. This chapter and the next chapter are two of the most important chapters in the book. Chapter 4 presents another language called Web Ontology Language (OWL). Because RDFS is quite primitive as a modeling language for the Web, more powerful languages are needed. A richer language. DAML+OIL, is thus proposed as a joint endeavor of the United States and Europe. OWL takes DAML+OIL as the starting point, and aims to be the standardized and broadly accepted ontology language. At the beginning of the chapter, the nontrivial relation with RDF/RDFS is discussed. Then the authors describe the various language elements of OWL in some detail. Moreover, Appendix A contains an abstract OWL syntax. which compresses OWL and makes OWL much easier to read. Chapter 5 covers both monotonic and nonmonotonic rules. Whereas the previous chapter's mainly concentrate on specializations of knowledge representation, this chapter depicts the foundation of knowledge representation and inference. Two examples are also givwn to explain monotonic and non-monotonic rules, respectively. "To get the most out of the chapter. readers had better gain a thorough understanding of predicate logic first. Chapter 6 presents several realistic application scenarios to which the Semantic Web technology can be applied. including horizontal information products at Elsevier, data integration at Audi, skill finding at Swiss Life, a think tank portal at EnerSearch, e-learning. Web services, multimedia collection indexing, online procurement, raid device interoperability. These case studies give us some real feelings about the Semantic Web.
The chapter on ontology engineering describes the development of ontology-based systems for the Web using manual and semiautomatic methods. Ontology is a concept similar to taxonomy. As stated in the introduction, ontology engineering deals with some of the methodological issues that arise when building ontologies, in particular, con-structing ontologies manually, reusing existing ontologies. and using semiautomatic methods. A medium-scale project is included at the end of the chapter. Overall the book is a nice introduction to the key components of the Semantic Web. The reading is quite pleasant, in part due to the concise layout that allows just enough content per page to facilitate readers' comprehension. Furthermore, the book provides a large number of examples, code snippets, exercises, and annotated online materials. Thus, it is very suitable for use as a textbook for undergraduates and low-grade graduates, as the authors say in the preface. However, I believe that not only students but also professionals in both academia and iudustry will benefit from the book. The authors also built an accompanying Web site for the book at http://www.semanticwebprimer.org. On the main page, there are eight tabs for each of the eight chapters. For each tabm the following sections are included: overview, example, presentations, problems and quizzes, errata, and links. These contents will greatly facilitate readers: for example, readers can open the listed links to further their readings. The vacancy of the errata sections also proves the quality of the book."

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Footnote

Rez. in: Information - Wissenschaft und Praxis 56(2004) H.1, S.61-62 (D. Lewandowski): "Die Autoren des vorliegenden Bandes haben sich in den letzten Jahren durch ihre zahlreichen Veröffentlichungen zum Verhalten von Suchmaschinen-Nutzern einen guten Namen gemacht. Das nun erschienene Buch bietet eine Zusammenfassung der verstreut publizierten Aufsätze und stellt deren Ergebnisse in den Kontext eines umfassenderen Forschungsansatzes. Spink und Jansen verwenden zur Analyse des Nutzungsverhaltens query logs von Suchmaschinen. In diesen werden vom Server Informationen protokolliert, die die Anfragen an diesen Server betreffen. Daten, die aus diesen Dateien gewonnen werden können, sind unter anderem die gestellten Suchanfragen, die Adresse des Rechners, von dem aus die Anfrage gestellt wurde, sowie die aus den Trefferlisten ausgewählten Dokumente. Der klare Vorteil der Analyse von Logfiles liegt in der Möglichkeit, große Datenmengen ohne hohen personellen Aufwand erheben zu können. Die Daten einer Vielzahl anonymer Nutzer können analysiert werden; ohne dass dabei die Datenerhebung das Nutzerverhalten beeinflusst. Dies ist bei Suchmaschinen von besonderer Bedeutung, weil sie im Gegensatz zu den meisten anderen professionellen Information-Retrieval-Systemen nicht nur im beruflichen Kontext, sondern auch (und vor allem) privat genutzt werden. Das Bild des Nutzungsverhaltens wird in Umfragen und Laboruntersuchungen verfälscht, weil Nutzer ihr Anfrageverhalten falsch einschätzen oder aber die Themen ihrer Anfragen nicht nennen möchten. Hier ist vor allem an Suchanfragen, die auf medizinische oder pornographische Inhalte gerichtet sind, zu denken. Die Analyse von Logfiles ist allerdings auch mit Problemen behaftet: So sind nicht alle gewünschten Daten überhaupt in den Logfiles enthalten (es fehlen alle Informationen über den einzelnen Nutzer), es werden keine qualitativen Informationen wie etwa der Grund einer Suche erfasst und die Logfiles sind aufgrund technischer Gegebenheiten teils unvollständig. Die Autoren schließen aus den genannten Vor- und Nachteilen, dass sich Logfiles gut für die Auswertung des Nutzerverhaltens eignen, bei der Auswertung jedoch die Ergebnisse von Untersuchungen, welche andere Methoden verwenden, berücksichtigt werden sollten.