slides_chap11 Modern Information Retrieval 2e 英文课件.pdf

Modern Information Retrieval Chapter 11 Web Retrieval with Yoelle Maarek A Challenging Problem The Web Search Engine Architectures Search Engine Ranking Managing Web Data Search Engine User Interaction Browsing Beyond Browsing Related Problems Web Retrieval, Modern Information Retrieval, Addison Wesley, 2010 – p. 1 Introduction The Web very large, public, unstructured but ubiquitous repository need for efficient tools to manage, retrieve, and filter information search engines have become a central tool in the Web Two characteristics make retrieval of relevant information from the Web a really hard task the large and distributed volume of data available the fast pace of change Web Retrieval, Modern Information Retrieval, Addison Wesley, 2010 – p. 2 A Challenging Problem Main challenges posed by Web are of two types data-centric: related to the data itself interaction-centric: related to the users and their interactions Data-centric challenges are varied and include distributed data high percentage of volatile data large volume of data unstructured and redundant data quality of data heterogeneous data Web Retrieval, Modern Information Retrieval, Addison Wesley, 2010 – p. 3 A Challenging Problem Second class of challenges — interaction-centric expressing a query interpreting results User key challenge to conceive a good query System key challenge to do a fast search and return relevant