Opinion Sentence Search Engine on Open-domain Blog

Osamu Furuse, Nobuaki Hiroshima, Setsuo Yamada, Ryoji Kataoka

NTT Cyber Solutions Laboratories,NTT Corporation

IJCAI 2007

Reporter: Chia-Ying Lee

Advisor: Hsin-Hsi Chen

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Introduction

A user want to know others’ opinion about a product or something

Input: query phrase Output: relevant opinion sentence

Explicitly stated opinion sentence Exclude quoted or implicational opinions Including positive, negative and neutral Opinion clues

Opinion Sentences to be Searched Opinion clues [Hiroshima et al. 2006]

1. Evaluative adjectives placed in the predicate partThis house is beautiful.

2. Subjective sentential adverbs( 全句副詞 )Amazingly, few people came to my party.

3. Idiomatic collocations ( 慣用語搭配 ) in main clauseMy wish is to go abroad.

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Architecture of Opinion Sentence Search(1/3)

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Architecture of Opinion Sentence Search(2/3)

High proportion off-line processing

Presented in a blog page unit Ranked according to

The number The ratio Total strength

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Architecture of Opinion Sentence Search(3/3)

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Opinion Sentence Extraction(1/4) Opinion clue expression collection

Top 20 web pages with 40 queries 13,363 opinion sentences judged by all

3 evaluator 2,936 opinion clues judged by human

Japanese predicates are in principle placed in the last part of a sentence. 2,514 clues in predicates ; 422 not in.

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Opinion Sentence Extraction(3/4)

Augmentation by semantic categories

Opinion clue expressions and co-occurring words(X) The sky is high.(O) The quality of this product is

high.

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Opinion Sentence Extraction(4/4)

Binary classifies sentences using SVM Features:

2,936 opinion clue expressions 2,715 semantic categories 150 frequent words 13 parts of speech

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Number Train set

Test set

Query 72 18

Total sentence 23,800 5,686

Sentence at least one judged opinions

8,050 1,791

Query-relevant Sentence Extraction

Accepting weak query relevance Strategies about query relevant

(a) A query phrase occurs in the sentence or within some number of sentences before the sentence.(b) A query phrase occurs in the sentence or within the chunk opinion sentences consecutively appear in.

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Experiment ─Opinion Sentence Extraction(1/2)

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Baseline: Regards a sentence contain more than 4 opinion clues as a opinion sentence

Experiment ─Opinion Sentence Extraction(2/2)

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Quasi predicate part: Features are permitted only within the last ten words in the sentence

Recall: 74.3 % to 3 judged 62.0 % to 2 judged

44.4 % to 1 judged

Experiment ─ Query Relevance

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Baseline: A query phrase occurs in the sentenceData set: 2,868 opinion sentences

Experiment ─ total performance

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Data set: 429 query-relevant opinion sentence out of 5,686 sentences (7.5%)

Opinion sentences tend to be more query-relevant than non-opinion sentences.

Conclusion and Future Work

The experiments suggested that the system is a practical application

Improve query-relevant strategy Classify opinion sentences in terms

of emotion, sentiment, requirement, and suggestion

Summarize

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Thank You!