sentiment analysis (thanks to matt baker). introduction what how conclusion laptop purchase how will...
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Sentiment Analysis
(thanks to Matt Baker)
IntroductionWhatHowConclusion
Laptop Purchase
How will you decide?
IntroductionWhatHowConclusion
Survey Says
81% internet users
• online product research 1+ times
20% internet users
• online product research daily
73-87% consumers of restaurant, hotel, service reviews
• reviews significantly impact purchasing decisionscomScore/the Kelsey group, “Online consumer-generated reviews have significant impact on offline purchase behavior,” Press Release, http://www.comscore.com/press/release.asp?press=1928, November 2007.Quoted in Pang and Lee, 2008, “Opinion Mining and Sentiment Analysis”
IntroductionWhatHowConclusion
Survey Says
20-99% consumers
• willing to pay more for 5- than 4-star-rated product
32% consumers
• rated online product, service, person
30% consumers
• posted online comment or reviewJ. A. Horrigan, “Online shopping,” Pew Internet & American Life Project Report, 2008.Quoted in Pang and Lee, 2008, “Opinion Mining and Sentiment Analysis”
Introduction WhatHowConclusion
Definition
Many scholars view sentiment analysis as “the computational treatment of opinion,
sentiment, and subjectivity in text”*
How do each of these terms differ?
*Pang 2008, pg. 8
Introduction WhatHowConclusion
Review of Literature
• Uses machine learning to assess polarity (positive, negative, neutral) in movie reviews– Pang, Lee, & Vaithyanathan (2002)
• Evaluates sentiment based on parts of speech (adjectives and adverbs)– Turney (2002)
Introduction WhatHowConclusion
Review of Literature
• Separates objective from subjective statements and assess polarity of opinion sentences– Yu & Hatzivassiloglou (2003)
• Identifies valence shifters in text that can give information regarding the writer’s sentiment– Polanyi & Zaenen (2004)
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Review of Literature
• Expands sentiment analysis to include rankings on a scale– Pang & Lee (2005)
• Selects features from text and performs sentiment analysis on a feature level– Durant & Smith (2007)
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How would you extract sentiment from Tweets?
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Considerations
• Parts of speech• Objective statements• Subjective statements• Binary classification• Ranking• Features• Overall sentiment• Domain• Word position
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Considerations• Valence shifters*
– Words– Negation– Intensifiers– Modal operators– Irony
• Pronoun resolution• Topic relevance• Unigrams, bigrams, etc.• Syntax• Strength of polarity
*Polanyi & Zaenen (2004)
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Twitter Literature
• Sentiment word frequencies*• Emoticons ***• Unigrams***• Bigrams***• Parts of Speech***
*O’Conner et al. 2010***Go 2009
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Sample reviews (negative polarity)
• a peculiar misfire that even tunney can't save . • watching queen of the damned is like reading a
research paper , with special effects tossed in . • i can't remember the last time i saw worse stunt
editing or cheaper action movie production values than in extreme ops .
• too much of nemesis has a tired , talky feel . • i felt trapped and with no obvious escape for the
entire 100 minutes . • a baffling mixed platter of gritty realism and
magic realism with a hard-to-swallow premise . • an affable but undernourished romantic comedy
that fails to match the freshness of the actress-producer and writer's previous collaboration , miss congeniality
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Sample reviews (positive polarity)
• emerges as something rare , an issue movie that's so honest and keenly observed that it doesn't feel like one .
• the film provides some great insight into the neurotic mindset of all comics -- even those who have reached the absolute top of the game .
• offers that rare combination of entertainment and education . • perhaps no picture ever made has more literally showed that
the road to hell is paved with good intentions . • offers a breath of the fresh air of true sophistication . • a thoughtful , provocative , insistently humanizing film . • not for everyone , but for those with whom it will connect ,
it's a nice departure from standard moviegoing fare .• is it a total success ? no . is it something any true film
addict will want to check out ? you bet . • engrossing and affecting , if ultimately not quite satisfying
.
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Lexical characterizations
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Tools: SentiWordNet
http://sentiwordnet.isti.cnr.it/
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Tools: Opinon Lexicon
http://www.cs.uic.edu/~liub/FBS/sentiment-analysis.html#lexicon
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Online data / demos / tools
• Movie review data• NLTK
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Systems
• LingPipe: tutorial and system you can install
• Weka: blog and instructions • R: blog and pointer to code
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Methods: Linear Regression
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Example
Twitter with R*
*https://github.com/jeffreybreen/twitter-sentiment-analysis-tutorial-201107/blob/master/R/0_start.R*http://www.inside-r.org/howto/mining-twitter-airline-consumer-sentiment
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Other applications
• Classifying speeches as for or against issues*• Discovering the political leanings of texts**• Sensing user annoyance by computers to
change interaction methods***• Monitoring violent and hateful
propaganda****• Tracking the world’s mood*****• Scanning emails
*Thomas, et al. 2006**Pang 2008***Liscombe et al. 2005****Abassi 2007
References• A. Abbasi, “Affect intensity analysis of dark web forums,” in Proceedings of Intelligence and Security Informatics (ISI),
pp. 282–288, 2007.• Bo, Pang, and Lillian Lee. "Opinion Mining and Sentiment Analysis." Foundations & Trends in Information Retrieval 2,
no. 1/2 (2008): 1-135.• Bo, Pang, Lillian Lee, and Shivakumar Vaithyanathan. “Thumbs up? Sentiment Classification using Machine Learning
Techniques. Proceedings of the Conference on Empirical Methods in Natural Language Processing. (2002).• Durant, Kathleen and Michael Smith. “Predicting the Political Sentiment of Web Log Posts using Supervised Machine
Learning Techniques Coupled with Feature Selection.” 2007.• Go, Alec. “Twitter Sentiment Analysis.” 2009.• J. Liscombe, G. Riccardi, and D. Hakkani-T¨ur, “Using context to improve emotion detection in spoken dialog systems,”
in Interspeech, pp. 1845–1848, 2005.• M. Thomas, B. Pang, and L. Lee, “Get out the vote: Determining support or opposition from congressional floor-debate
transcripts,” in Proceedings of the Conference on Empirical Methods in Natural Language Processing (EMNLP), pp. 327–335, 2006.
• O’Connor, Brandon, Ramnath Balasubramanyan, Bryan R. Routledge, and Noah A. Smith. “From Tweets to Polls: Linking Text Sentiment to Public Opinion Time Series.” 2010.
• Pang, Bo and Lillian Lee. “Seeing stars: Exploiting class relationships for sentiment categorization with respect to rating scales.” 2005.
• Polanyi, Livia and Annie Zaenen. “Contextual valence shifters.” Computing attitude and affect in text: Theory and applications. 2006.
• Turney, Peter. “Thumbs up or Thumbs Down? Semantic Orientation Applied to Unsupervised Classification of Reviews.” Proceedings of the 40th Annual Meeting of the Association for Computational Linguistics. (2002).
• Yu, Hong and Vasileios Hatzivassiloglou. “Towards answering opinion questions: separating facts from opinions and identifying the polarity of opinion sentences.” Proceedings of the 2003 conference on Empirical methods in natural language processing. 2003.