Presentation on theme: "Social + Mobile + Commerce Entity Extraction, Linking, Classification, and Tagging for Social Media: A Wikipedia Based Approach Aug 27th, 2013 Abhishek."— Presentation transcript:
Social + Mobile + Commerce Entity Extraction, Linking, Classification, and Tagging for Social Media: A Wikipedia Based Approach Aug 27th, 2013 Abhishek Gattani, Digvijay Lamba, Nikesh Garera, Mitul Tiwari 3, Xiaoyong Chai, Sanjib Das 1, Sri Subramaniam, Anand Rajaraman 2, Venky Harinarayan 2, AnHai Doan 1 ; @WalmartLabs, 1 University of Wisconsin-Madison, 2 Cambrian Ventures, 3 LinkedIn
The Problem “Obama gave an immigration speech while on vacation in Hawaii” Entity Extraction“Obama” is a Person, “Hawaii” is a location Entity Linking“Obama” -> en.wikipedia.org/wiki/Barack Obama “Hawaii” -> en.wikipedia.org/wiki/Hawaii Classification“Politics”, “Travel” Tagging“Politics”, “Travel”, “Immigration”, “President Obama”, “Hawaii” On Social Media Data Short SentencesUngrammatical, misspelled, lots of acronyms Social ContextFrom previous conversation/interests: “Go Giants!!” Large Scale10s of thousands of updates a second Lots of TopicsNew topics and themes every day. Large scale of topics
Why? – Use cases Used extensively at Kosmix and later at @WalmartLabs –Twitter event monitoring –In context ads –User query parsing –Product search and recommendations –Social Mining Use Cases –Central topic detection for a web page or tweet. –Getting a stream of tweets/messages about a topic. Small team at scale –About 3 engineers at a time –Processing the entire Twitter firehose
Based on a Knowledge Base Published: Building, maintaining, and using knowledge bases: A report from the trenches. In SIGMOD, 2013. Global: Covers a wide range of topics. Includes WordNet, Wikipedia, Chrome, Adam, MusicBrainz, Yahoo Stocks etc. Taxonomy: Converted Wikipedia graph to a hierarchical taxonomy with IsA edges which are transitive Large: 6.5 Million hierarchical concepts with 165 Million relationships Real Time: Constantly updated from sources, analyst curation, event detection Rich: Synonyms, Homonyms, Relationships, etc
Annotate with Contexts A Real Time User Context What topics does this user talk about? A Real Time Social Context What topics are usually in context of a Hashtag, Domain, or KB Node A Web Context Topics in a link in a tweet. What are the topics in KB Node’s Wiki Page? Compute the context at scale Every social conversation takes place in a context that changes what it means
Example Contexts Barack ObamaSocial: Putin, Russia, White House, SOPA, Syria, Homeownership, Immigration, Edward Snowden, Al Qaeda Web: President, White House, Senate, Illinois, Democratic, United States, US Military, War, Michelle Obama, Lawyer, African American www.whitehouse.govSocial: Petition, Barack Obama, Change, Healthcare, SOPA #PoliticsSocial: Barack Obama, Russia, Rick Scott, State Dept, Egypt, Snowden, War, Washington, House of Representatives @WhitehouseUser: Barack Obama, Housing Market, Homeownership, Mortgage Rates, Phoenix, Americans, Middle Class Families
Key Differentiators – why it works? The Knowledge Base Interleave several problems Use of Context Scale Rule Based
How: First Find Candidate Mentions “RT Stephen lets watch. Politics of Love is about Obama’s election @EricSu” Step 1: Pre-Process – clean up tweet “Stephen lets watch. Politics of Love is about Obama’s election” Step 2: Find Mentions – All in KB + detectors [“Stephen”, “lets”, “watch” “Politics”, “Politics of Love”, “is”, “about”, “Obama”, “Election”] Step 3: Initial Rules – Remove obvious bad cases [“Stephen”, “watch”, “Politics”, “Politics of Love”, “Obama”, “Election”] Step 4: Initial scoring – Quick and dirty [“Obama”: 10, “Politics of Love”: 9, “Stephen”:7, “watch”: “7”., “Politics”: 6, “Election”: 6,]
How: Add mention features Step 5: Tag and Classify– Quick and dirty “Obama”: Presidents, Politicians, People; Politics, Places, Geography “Politics of Love”: Movies, Political Movies, Entertainment, Politics “Stephen”: Names, People “watch”: Verb, English Words, Language, Fashion Accessories, Clothing “Politics”: Politics “Election”: Political Events, Politics, Government Tweet: Politics, People, Movies, entertainment.. Etc. Step 6: Add features Contexts, similarity to the tweet, similarity to user or website, popularity measures, is it interesting?, social signals
How: Finalize mentions Step 7: Apply Rules “Obama”: Boost popular stuff and proper nouns “Politics of Love”: Boost Proper nouns, Boost due to “Watch” “Stephen”: Delete out of context names “watch”: Remove verbs “Politics”: Boost tags which are also mentions “Election”: Boost mentions in the central topic Step 8: Disambiguate KB has many meanings – Pick One Obama: Barrack Obama. Popularity, Context, Social Popularity Watch: verb. Clothing is not in context Context is most important! We use many contexts for most success.
How: Finalize Step 9: Rescore Logistic Regression model on all the features Step 9: Re-tag Use latest scores and only picked meanings Step 9: Editorial Rules A regular expression like language for analysts to pick/book
Does it work? – Evaluation of Entity Extraction For 500 English Tweets we hand curate a list of mentions. For 99 of those built a comprehensive list of tags. Entity extraction: Works well for people, organizations, locations Works great for unique names Works badly for Media: Albums, Songs, Generic Problem: Too many movies, books, albums and songs have “Generic” Names Inception, It’s Friday etc. Even when popular they are often used “in conversation” Very hard to disambiguate. Very hard to find which ones are Generic.
Does it work? – Evaluation of Tagging Tagging/Classification: Works well for Travel/Sports Bad for Products and Social sciences N Lineages problem: Note that all mentions have multiple lineages in the KB. Usually, one IsA lineage goes to “People” or “Product” A ContainedIn lineage goes to the topic like “SocialScience” Detecting which is primary is a hard problem. Is Camera in Photography? Or Electronics? Is War History? Or Politics? How far do we go?
Comparison with existing systems The first such comparison effort that we know of. OpenCalais –Industrial Entity Extraction system StanNER-3: (From Stanford) –This is a 3-class (Person, Organization, Location) named entity recognizer. The system uses a CRF-based model which has been trained on a mixture of CoNLL, MUC and ACE named entity corpora. StanNER-3-cl: (From Stanford) –This is the caseless version of StanNER-3 system which means it ignores capitalization in text. StanNER-4: (From Stanford) –This is a 4-class (Person, Organization, Location, Misc) named entity recognizer for English text. This system uses a CRF-based model which has been trained on the CoNLL corpora.
For People, Organization, Location Details in the Paper. We are far better on almost all respects: –Overall: 85% Precision vs 78% best in other systems. –Overall: 68% Recall vs 40% for StanNER-3 and 28% for OpenCalais –Significantly better on Organizations Why? - Bigger Knowledge Base –The larger knowledge base allows a more comprehensive disambiguation. –Is “Emilie Sloan” referring to a person or organization? Why? - Common interjections –LOL, ROFL, Haha interpreted as organizations by other systems. –Acronyms misinterpreted Vs OpenCalais –Recall is a major difference with a significantly smaller set of entities recognized by Open Calais
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