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

2008/01/15 Chia-Ying Lee2 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 part This 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 clause My wish is to go abroad. 2008/01/15 Chia-Ying Lee3

Architecture of Opinion Sentence Search(1/3) 2008/01/15 Chia-Ying Lee4

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 2008/01/15 Chia-Ying Lee5

Architecture of Opinion Sentence Search(3/3) 2008/01/15 Chia-Ying Lee6

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. 2008/01/15 Chia-Ying Lee7

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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. 2008/01/15 Chia-Ying Lee9

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 2008/01/15 Chia-Ying Lee10 NumberTrain setTest set Query7218 Total sentence23,8005,686 Sentence at least one judged opinions8,0501,791

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. 2008/01/15 Chia-Ying Lee11

Experiment ─ Opinion Sentence Extraction(1/2) 2008/01/15 Chia-Ying Lee12 Baseline: Regards a sentence contain more than 4 opinion clues as a opinion sentence

Experiment ─ Opinion Sentence Extraction(2/2) 2008/01/15 Chia-Ying Lee13 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 2008/01/15 Chia-Ying Lee14 Baseline: A query phrase occurs in the sentence Data set: 2,868 opinion sentences

Experiment ─ total performance 2008/01/15 Chia-Ying Lee15 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 2008/01/15 Chia-Ying Lee16

2008/01/15 Chia-Ying Lee17 Thank You!