Extract Questions from Sentences

Purpose

• The behavior of extracting questions from sentences can be regarded as extracting semantics or knowledge from passages.

• The knowledge extracted can be used to– Answer queries directly– Support semantic computing

A Blueprint (Ultimate Goal)

• What is the difference between football and basketball?– Learn passages about football and basketball.– Get the knowledge from the passages that they are

two kinds of team sports.– Learning passages about team sports to get the

knowledge of what aspects a team sport involves.– Using the commonsense that difference should be

worked out by comparing every aspects of each side of comparison.

– List every aspects of the two sport that are different.

Problems

• A series of problems involved– Knowledge extracting from sentences– Knowledge expressing and storage– Knowledge organization (indexing, grouping and

linking)– Knowledge update– Knowledge utilization– Knowledge source– Conflict resolution– …

Knowledge extracting

Knowledge extracting

• Extracting knowledge from sentences– Knowledge within a single sentence – Knowledge across several sentences later

• In order to represent the knowledge extracted from sentences before having a mature way to express the knowledge, they will be expressed by just asking simple questions.

• The task is simplified as extracting questions from sentences.

Category of Sentences

• Purpose of sentences– Declarative Sentence – Interrogative Sentence (疑问句 ) X– Imperative Sentence (祈使句 ) X– Exclamatory Sentence (感叹句 ) later

• Structure of sentences– Simple sentence first– Sentence with one or more clauses later

Declarative Sentence

• Almost every syntax component can be asked in the sentence.

• Subject

• Predicate

• Complement

• Prepositional phrase (manner, reason, time, location, person, …)

• …

Basic Grammar Patterns of DS

• Subject + Predicate– What does [subject] do?– Who/What does …?

• Subject + be + object– What is [subject]?

• Subject + linking verb + complement– How does [subject] [linking verb]– A[n] looks[lv] like[prep] B[n].

• How does A look?• What/Who does A/B look like?

• …

Lexical Analysis

• Make use of WordNet– Nouns, verbs, adjectives and adverbs.

• Prepositions

What to do in the following week

Do information gathering work focusing on Simple Sentence (without clauses).

• Conclude the basic patterns that appear frequently. (increasingly)

• Find the syntax components of sentences in each pattern that people care most and the way to ask about them. (increasingly)

• Find a way to justify whether a given sentence matches any of the concluded pattern.