PPT-Search Engines Information Retrieval in Practice

All slides Addison Wesley 2008 TexPoint fonts used in EMF Read the TexPoint manual before you delete this box A A Processing Text Converting documents to index terms Why Matching the exact string of characters typed by the user is too restrictive. Italo . Trevisan. ). Search. . Engine. . definition. A.  computer program that searches documents, especially on the. . World Wide Web, . for a specified word or words and provides a list of documents in which they are found. Information Retrieval in Practice. All slides ©Addison Wesley, 2008. Search and Information Retrieval. Search on the Web. 1. is a daily activity for many people throughout the world. S. earch and communication are most popular uses of the computer. CSC . 575. Intelligent Information Retrieval. 2. Source: . Intel. How much information?. Google: . ~100 . PB a . day; 3+ million servers (15 . Exabytes. stored). Wayback Machine has . ~9 . PB + . 100 . Information Retrieval. Information Retrieval. Konsep. . dasar. . dari. IR . adalah. . pengukuran. . kesamaan. sebuah. . perbandingan. . antara. . dua. . dokumen. , . mengukur. . sebearapa. . ChengXiang. (“Cheng”) . . Zhai. Department of Computer Science. University of Illinois at Urbana-Champaign. http://www.cs.uiuc.edu/homes/czhai. . Email: czhai@illinois.edu. 1. Yahoo!-DAIS Seminar, UIUC. Finding What You’re Looking For. First, Ask a Question . . .. The Search Question. Creating a good search question is half the battle. Types of questions:. Specific: you want the answer to a specific question. Hongning. Wang. CS@UVa. Classical search engine architecture. “The . Anatomy of a Large-Scale . Hypertextual. Web Search . Engine”. - Sergey . Brin. and . Lawrence Page, . Computer networks and ISDN systems. Hongning. Wang. CS@UVa. Classical search engine architecture. “The . Anatomy of a Large-Scale . Hypertextual. Web Search . Engine”. - Sergey . Brin. and . Lawrence Page, . Computer networks and ISDN systems. All slides ©Addison Wesley, 2008. Social Search. Social search . Communities. of users . actively participating. in the search process. Goes beyond classical search tasks. Key differences. Users interact with the system. All slides ©Addison Wesley, 2008. Beyond Bag of Words. “Bag of Words”. a document is considered to be an unordered collection of words with no relationships. Extending representation. feature-based models. Class Activity. Action: . Write. down the . 4 or 5 points. that most impact you from this presentation.. You will need this for the group activity at the end of this presentation.. Key to Learning. What is IR?. Sit down before fact as a little child, . be prepared to give up every conceived notion, . follow humbly wherever and whatever abysses nature leads, . or you will learn nothing. . . -- Thomas Huxley --. How much of the total web are you able to searchFreshness How often do their crawlers update the copies of the web pages you are searchingCompleteness of textIs the database really full text or only p Retrieval Practice: Lesson 3. 1. What is an . autobiography. ?.  .  2. Does Roald Dahl consider . Boy . to be an . autobiography. ? Why or why not?.  .  3. What is an . anecdote. ?.  . 4. Describe one .