Mining and Summarizing Customer Reviews Lucas Rizoli 2007-11-20 CPSC 503

Hu & Liu, 2004a Mining and Summarizing Customer Reviews Hu & Liu, 2004b Mining Opinion Features in Customer Reviews

Hu & Liu, 2004a

Mining and Summarizing Customer Reviews

Hu & Liu, 2004b

Mining Opinion Features in Customer Reviews

From http://www.amazon.com/Pearl-Harbor-Two-Disc-Anniversary-Commemorative/dp/B00003CXTG/

From http://www.amazon.com/Pearl-Harbor-Two-Disc-Anniversary-Commemorative/dp/B00003CXTG/

From http://www.amazon.com/Pearl-Harbor-Two-Disc-Anniversary-Commemorative/dp/B00003CXTG/

From http://www.amazon.com/Pearl-Harbor-Two-Disc-Anniversary-Commemorative/dp/B00003CXTG/

From http://www.amazon.com/Pearl-Harbor-Two-Disc-Anniversary-Commemorative/dp/B00003CXTG/ Plot Acting Special Effects Historical accuracy Sound quality …

From http://www.amazon.com/Pearl-Harbor-Two-Disc-Anniversary-Commemorative/dp/B00003CXTG/ I want a summary Feature-by-feature evaluation Use all reviews

Major phases Finding features “ Pearl Harbor ’s plot is totally crap” Identifying opinions “ Pearl Harbor ’s plot is totally crap ” Producing a summary Extractive, list-style

Finding features

“ Pearl Harbor ’s plot is totally crap”

Identifying opinions

“ Pearl Harbor ’s plot is totally crap ”

Producing a summary

Extractive, list-style

Finding features Frequent feature phrases Noun phrases of 3 words or less In > 1% of reviews in corpus Keep compact feature phrases Phrase words < 3 words apart In > 1 sentence in corpus Trim redundant phrases

Frequent feature phrases

Noun phrases of 3 words or less

In > 1% of reviews in corpus

Keep compact feature phrases

Phrase words < 3 words apart

In > 1 sentence in corpus

Trim redundant phrases

Identifying opinions Opinion sentences Include a feature phrase Associate nearest adjective with feature “ The ‘splosions are freakin’ amazing ”

Opinion sentences

Include a feature phrase

Associate nearest adjective with feature

“ The ‘splosions are freakin’ amazing ”

Uncommon features Infrequent features may be useful “ Kate Beckinsale’s hair : beautiful” Use adjective to identify feature Add nearest noun phrase to features Adds spurious features? Only 15–20% of features Countered by ranking by frequency

Infrequent features may be useful

“ Kate Beckinsale’s hair : beautiful”

Use adjective to identify feature

Add nearest noun phrase to features

Adds spurious features?

Only 15–20% of features

Countered by ranking by frequency

Word orientation Positive or negative? Seed set of 30 words Use syn/antonymy to tag related words Use WordNet to find related words

Positive or negative?

Seed set of 30 words

Use syn/antonymy to tag related words

Use WordNet to find related words

new fresh original innovative +

new fresh original innovative + + + +

unoriginal new fresh original innovative + + + +

unoriginal new fresh original innovative + − + + +

unoriginal new banal hackneyed trite fresh original innovative + − + + + − − −

Sentence orientation Average of opinion in sentence If none, use previous sentence Use nearby negations Near if < 5 words away Invert nearest opinion Use opinion in “but” clause If none, invert initial opinion

Average of opinion in sentence

If none, use previous sentence

Use nearby negations

Near if < 5 words away

Invert nearest opinion

Use opinion in “but” clause

If none, invert initial opinion

Summary Group sentences by feature Divide by orientation Rank features by frequency Display some for each feature Pro/Con-style, by-feature

Group sentences by feature

Divide by orientation

Rank features by frequency

Display some for each feature

Pro/Con-style, by-feature

Finding features 0.72 0.80 Uncommon 0.79 0.66 Redundancy 0.66 0.67 Compactness 0.56 0.68 Frequency Precision Recall

Identifying opinions Word orientation Recall: 0.69 Precision: 0.64 Sentence orientation Accuracy: 0.84

Word orientation

Recall: 0.69

Precision: 0.64

Sentence orientation

Accuracy: 0.84

Evaluation issues Implicit features “ Planes were small” -> historical accuracy Easy for human taggers to find Story-telling Adjectives in feature-free sentences Orientation is subjective Some evaluations hard to classify

Implicit features

“ Planes were small” -> historical accuracy

Easy for human taggers to find

Story-telling

Adjectives in feature-free sentences

Orientation is subjective

Some evaluations hard to classify

Future work More opinion words Include verbs and other modifiers Opinion strength “ It’s crummy” vs. “It’s worse than death” Pronoun resolution What is “it?”

More opinion words

Include verbs and other modifiers

Opinion strength

“ It’s crummy” vs. “It’s worse than death”

Pronoun resolution

What is “it?”