Web Opinion Mining Praesentation

7/28/2019 Web Opinion Mining Praesentation

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Marc-Antoine Dupr

Alexander Patronas

Erhard Dinhobl

Ksenija Ivekovic

Martin Trenkwalder

Web Opinion Mining


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Roadmap

What is opinion mining and why?

Objects, model and task

Words and phrases

Sentiment classification Feature-based opinion mining

Opinion Spam

Tools on opinion mining


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Questions:

What do users think about a specific product?

Which of our customers are unsatisfied? Why?

Which product is more popular among users?

Answer: Web Opinion Mining


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Web Opinion Mining

Facebook, blogs, > opin ion

Wikipedia > fact

Opinions: underlying question

what do people in America think about BarackObama?

Mostly in deep web

AI algorithm necessary

Useful: market intelligence (better ads)


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Objects, Model Opinion holder / object / opinion Features of object

F = {f1, f2, f3, } fi F

fi

defined by words or phrasesW = {w1, w2, w3, } Wi W

O is some object (event, person, product, )

Now the opinion holder is j and comments on a subset offeatures Sj of F of O. Now feature fk Sj is commented by j by aword or phrase from Wk to determine the feature and a positive,negative or neutral opinion on fk


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Task One document one opinion from one holder Opinion: positive, negative, neutral

3 levels: Document - class determining

Sentence (one opinion) sentence type (objective or subjective)

sentence class (neutral, positive, negative)

Feature determining words and phrases


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Words and Phrases

Words often context dependent (long longloading time long battery runtime)

3 approaches to get wordlist: Manual approach

Corpus-based approach

Dictionary-based approach


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Sentiment Classification Classify documents (e.g. reviews) based on

overall sentiments expressed by opinion holders Positive, negative or neutral

Useful, but doesnt find what reviewer liked ordisliked!A negative sentiment on an object doesnt mean

that opinion holder dislikes everything about object

and opposite

Need to go to sentence level and the feature level


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Feature-based Opinion Mining

Objective: find what reviewers like and dislike Features and components

Three tasks: Extract object features that have been commented

on in each review

Determine whether opinions on the feature are

positive, negative or neutral

Group synonyms and produce summary


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Different Review Formats

GREAT Camera., Jun 3, 2004

Reviewer:jprice174 from Atlanta, Ga.

I did a lot of research last year before Ibought this camera... It kinda hurt toleave behind my beloved nikon 35mmSLR, but I was going to Italy, and Ineeded something smaller, and digital.

The pictures coming out of this cameraare amazing. The 'auto' feature takesgreat pictures most of the time. And withdigital, you're not wasting film if thepicture doesn't come out.

.


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Extracting Object Features

1. Part-of-speech tagging: Features are noun and noun phrases

2. Frequent features generation Association mining to generate candidate features

Feature pruning

3. Infrequent feature generation Opinion words extraction

Finding infrequent features using opinion words


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Identifying Orientation of Opinion

Sentence

Used dominant orientation of opinion words as

sentence orientation

If positive opinion prevails, the opinion sentence is

regarded as a positive and vice versa


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Feature-based Summary

GREAT Camera., Jun 3, 2004

Reviewer:jprice174 from Atlanta,Ga.

I did a lot of research last year

before I bought this camera... Itkinda hurt to leave behind mybeloved nikon 35mm SLR, but Iwas going to Italy, and I neededsomething smaller, and digital.

The pictures coming out of this

camera are amazing. The 'auto'feature takes great pictures mostof the time. And with digital, you'renot wasting film if the picturedoesn't come out.

.

Feature Based Summary:

Feature1: picture

Positive: 12 The pictures coming out of this camera

are amazing. Overall this is a good camera with a

really good picture clarity.

Negative: 2

The pictures come out hazy if yourhands shake even for a moment duringthe entire process of taking a picture.

Focusing on a display rack about 20feet away in a brightly lit room duringday time, pictures produced by thiscamera were blurry and in a shade oforange.

Feature2: battery life


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Opinion Spam

Reviews contain rich user opinions on products

and services, that possibly influence the purchase

decisions of users

Generally three types of spam reviews:

Untruthful opinions

Reviews on brands only Non-Reviews


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Tools for Sentiment Analysis [1/2]

APIs Evri semantic search engine, very powerful API

OpenDover Java based webservice

Blogosphere/Twittersphere

RankSpeed search by criterias

Twittratr simple search tool (keyword based)

TwitterSentiment project from Stanford University,classifiers from machine learning algorithms,

transparent


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Tools for Sentiment Analysis [2/2]

Newspaper Newssift sentiment search tool on newspapers

(by Financial Times)

Applications

LingPipe Java tool

Radian6 commercial social media monitoring

application

RapidMiner open-source machine learning and

data mining tool (Community Edition)


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LIVE DEMO (evri)


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Thank youfor your attention!

Documents

Web Opinion Mining Praesentation