Web Information Retrieval and Search

Web information retrieval and search deals with the information provisioning and information search on the World Wide Web. It is used by tourists to find information about, e.g., worldwide touristic services. The chapter starts with an introduction into information retrieval (IR) and the specifics of IR in the tourism domain where it is argued that not only information but real touristic services are searched for which requires also higher trust into found services and information. Further, the basics of IR in local information systems such as a generic retrieval model, indexing, retrieval functions, the relevance of found objects, and the evaluation of IR systems are described. For a large distributed information system as the Web with mostly unstructured or semi-structured content, specialized techniques such as crawling, automated indexing, text mining, computation of the relevance of objects, the ranking of results, and an extended architecture are described. Additionally, user profiling to achieve better matches for seekers is addressed. Web user behavior, Web site optimization, and keyword advertisement as technologies for marketing are included, as well as location-based services. Further, approaches to extract and transform semi-structured data into structured data, deep Web, as well as metasearch, i.e., searching over distributed structured information resources and aggregating search results, are described. Finally, crowd-based approaches such as social tagging to evaluate the quality and relevance of Web resources by users are presented and an outlook into trends is given.