QUESTION AND ANSWERING

Overview What is Question Answering? Why use it? How does it work? Problems Examples Future

What is it? Definition of Question Answering Examples  AskJeeves is probably most well known example  AnswerBus is an open-domain question answering system  Ionaut, EasyAsk, AnswerLogic, AnswerFriend, Start, LCC, Quasm, Mulder, Webclopedia, etc.

Why use it? From AskJeeves “Search engines do not speak your language. They make you speak their language; a language that's strange, confusing, and includes words that no one is entirely sure of their meaning.” QA engines attempt to let you ask your question the way you'd normally ask it. Inexperienced users Document=Answer?

How does it work? Natural Language Processing  Semantic Processing  Syntactic Processing  Parsing Knowledge Base Answer Processing

Natural Language Processing (NLP) Engines have unique processes START-Natural Language System  Parsing  Natural Language Annotation  Processing Component

QA SystemOutput AnswerBusSentences AskJeevesDocuments IONAUTPassages LCCSentences MulderExtracted answers QuASMDocument blocks STARTMixture WebclopediaSentences Answer Processing

AskJeeves Has own knowledge base and uses partners to answer questions Catalogues previous questions Answer processing engine  Question template response

AnswerBus

Problems How and Why questions What questions  What happened?  What did we do? Answer Quality  Correct??  Answer Presentation

Correct? (From Webclopedia) Question: Where do lobsters like to live? Answer: on a Canadian airline Question: Where do hyenas live? Answer: in Saudi Arabia Answer: in the back of pick-up trucks Question: Where are zebras most likely found? Answer: near dumps Answer: in the dictionary Question: Why can't ostriches fly? Answer: Because of American economic sanctions  Collected by Ulf Hermjakob --November 29, 2001

(TREC) -- Text Retrieval Conference Yearly information retrieval competition Began in 1992: QA in 1999 In order to encourage research into systems that return answers rather than document lists. Q’s are open domain, closed class A’s are less than 50 chars and entities or noun phrases

(TREC) -- Text Retrieval Conference 500 Questions in 2001  Some answers = nil; large difficulty  Lots of definition questions QA list tasks  Name 4 cities that have a “Shubert” theater. QA context tasks  How many species of spiders are there?  How many are poisonous to humans?  What percentage of spider bites in the US are fatal?

Example Questions and Results What river in the US is known as the Big Muddy? AskJeeves AnswerBus Google

Example Questions and Results What person’s head is on a dime? AskJeeves AnswerBus AltaVista

Example Questions and Results Show some paintings by Claude Monet START

Looking Ahead User Demand Enormous Interest in Problem Successes

Conclusion Question and Answering and Search Engines Why its used Future  Moore’s Law for QA???

Sources AskMSR: Question Answering Using the Worldwide Web  Michele Banko, Eric Brill, Susan Dumais, Jimmy Lin  etal-AAAI02.pdf etal-AAAI02.pdf  In Proceedings of 2002 AAAI SYMPOSIUM on Mining Answers from Text and Knowledge Bases, March 2002 Web Question Answering: Is More Always Better?  Susan Dumais, Michele Banko, Eric Brill, Jimmy Lin, Andrew Ng  Submit-Conf.pdf Submit-Conf.pdf

Sources AnswerBus    AskJeeves  Webclopedia   Start  Text Retrieval Conference 