1.Abstraction
several different techniques to answer extraction for factoid question answering
2.Introduction
types of question:
- definitional questions
- list questions
- scenario-based QA
- why-type questions
evaluation track of question answering systems:
- Text REtrieval Confererence(TREC)(Voorhees 2001,2003b)
- CLEF
- NTCIR(focus on European languages and Asia languages respectively)
why choose factoid questions?
- clear defined and relatively uncontroversial evaluation standards
- usually one or at most a few correct answers to given question
- the answer-a single word token or a short phrase
- the range in not very high,plenty of room for further improvement
Assessment classes of each factoid answer:
TREC&CLEF:
- correct
- correct+unsupported
- unsupported
- inxact(adj. 不确切的)
- incorrect
Assessment scores of each factoid answer:
- top1 and top5 accuracies
- Mean Reciprocal Rank(MRR)