Challenges in nlp

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Challenges in nlp

  1. 1. Challenges in NLP Zareen Syed zareensyed@gmail.com
  2. 2. Ambiguity • Natural language is highly ambiguous and must be disambiguated.
  3. 3. Ambiguity in Speech • Speech Recognition –“recognize speech” vs. “wreck a nice beach” –“youth in Asia” vs. “euthanasia”
  4. 4. 1. I saw the man. The man was on the hill. I was using a telescope. 2. I saw the man. I was on the hill. I was using a telescope. 3. I saw the man. The man was on the hill. The hill had a telescope. 4. I saw the man. I was on the hill. The hill had a telescope. 5. I saw the man. The man was on the hill. I saw him using a telescope. I saw the man on the hill with a telescope. Ambiguity in Preposition Attachment
  5. 5. Humor and Ambiguity • Many jokes rely on the ambiguity of language: – One morning I shot an elephant in my pajamas. How he got into my pajamas, I’ll never know. – She criticized my apartment, so I knocked her flat.
  6. 6. 7 Polysemy Word Sense Disambiguation (WSD) • Words in natural language usually have a fair number of different possible meanings. – Ellen has a strong interest in computational linguistics. – Ellen pays a large amount of interest on her credit card. – The dog is in the pen. – The ink is in the pen. – I put the plant in the window – Ford put the plant in Mexico • For many tasks (question answering, translation), the proper sense of each ambiguous word in a sentence must be determined.
  7. 7. Some more examples of Polysemy A world record. A record of the conversation. Record it! He left the bank five minutes ago. He left the bank five years ago He caught a fish at the bank. I need some paper. I wrote a paper. I read the paper.
  8. 8. Computers are no better than your dog. But we can teach them “how-to” by coding our knowledge of the language comprehension process
  9. 9. Co-Reference Resolution • Determine which phrases in a document refer to the same underlying entity. – John put the carrot on the plate and ate it. – Bush started the war in Iraq. But the president needed the consent of Congress.
  10. 10. Ellipsis Resolution • Frequently words and phrases are omitted from sentences when they can be inferred from context. "Wise men talk because they have something to say; fools, because they have to say something.“ (Plato) "Wise men talk because they have something to say; fools talk because they have to say something.“ (Plato)
  11. 11. 16 Information Extraction (IE) • Identify phrases in language that refer to specific types of entities and relations in text. • Named entity recognition is task of identifying names of people, places, organizations, etc. in text. people organizations places – Michael Dell is the CEO of Dell Computer Corporation and lives in Austin Texas. • Relation extraction identifies specific relations between entities. – Michael Dell is the CEO of Dell Computer Corporation and lives in Austin Texas.
  12. 12. Question Answering • Directly answer natural language questions based on information presented in a corpora of textual documents (e.g. the web). – When was Barack Obama born? (factoid) • August 4, 1961 – Who was president when Barack Obama was born? • John F. Kennedy – How many presidents have there been since Barack Obama was born? • 9
  13. 13. Projects & Research
  14. 14. Wikitology: A Novel Hybrid Knowledge Base Derived from Wikipedia Zareen Syed Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandyall the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val onlyto talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It'sbasically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandyall the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val onlyto talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It'sbasically between Francis and Val how would like to talk, or both, or what. Our plans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraser handy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The MetasystemTransition as the Quantumof Evolution". This is the theoretical base to the PCP, which I described the formof in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraser handy all the same. My life Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandyall the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only 19
  15. 15. Introduction and Motivation Page 20 Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandyall the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val onlyto talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It'sbasically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandyall the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val onlyto talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It'sbasically between Francis and Val how would like to talk, or both, or what. Our plans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraser handy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The MetasystemTransition as the Quantumof Evolution". This is the theoretical base to the PCP, which I described the formof in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplans are going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandy all the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only to talk on "The Metasystem Transition as the Quantum of Evolution". This is the theoretical base to the PCP, which I described the form of in my talk to WESS. It's basically between Francis and Val how would like to talk, or both, or what. Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraser handy all the same. My life Ourplansare going ahead, Heylighen is getting tickets, so let's put that in in hard pencil, but keep your eraserhandyall the same. My life is really hectic, and I won't be in a sane place till mid-April. We'll pin down the details later, but at this point we were considering Val only Human mind capable of understanding and reasoning over knowledge in different forms and is influenced by contextual factors World Knowledge is available in different forms Context important in understanding the semantics of data And may be available in different forms
  16. 16. Related Work Page 21 Michael Jackson Michael Joseph Jackson (August 29, 1958 – June 25, 2009) was an American singer-songwriter, dancer, actor, choreographer, businessman, philanthropist and record producer. Contents Life and Career Death . . See Also References External Links Typical Wikipedia Article Linked Open Data Wikipedia Derived Knowledge Resources Support Structured Queries Supports Natural Language Queries Wikitology Supports Hybrid Queries
  17. 17. Wikitology • Linked to LOD Cloud with over 295 datasets 22
  18. 18. Wikitology Document Concept Prediction • Identifying the topics and concepts associated with a document or collection of documents is a common task for many applications such as: – Annotation and categorization of documents in a corpus – Modelling user interests – Business intelligence – Selecting Advertisements Page 23
  19. 19. Test Document Title Method 1 Ranking Categories Directly Method 2 Spreading Activation Pulses=3 Weather Prediction of thunder storms (CNN) “Weather_Hazards” “Meterology” Prediction for Single Test Document Experiments More pulses -> More Generalized Concepts Data Set Method 1 Ranking Categories Directly Method 2 (2 pulses) Spreading Activation on Category links Graph Method 3 (2 pulses) Spreading Activation on Article Links Graph 10 articles related to Organic Farming Agriculture (Rank 1) Agriculture (in Top 5) Organic_farming (Rank 1) Prediction for a Set of Documents Concept not in the Category Hierarchy
  20. 20. Wikitology Cross Document Co-reference Resolution • Problem: – Determine whether various named entities in different documents refer to the same object in the world. • Are two documents that talk about “George Bush” talking about the same George Bush? – defined as a task in ACE Page 25
  21. 21. Wikitology Entity Linking • Research Problem: – Given an entity mention string and an article with that entity mention, find the link to the right Wikipedia entity if one exists. – Defined as a task in TAC KBP Track Page 26 John Williams Richard Kaufman goes a long way back with John Williams. Trained as a classical violinist, Californian Kaufman started doing session work in the Hollywood studios in the 1970s. One of his movies was Jaws, with Williams conducting his score in recording sessions in 1975... John Williams author 1922-1994 J. Lloyd Williams botanist 1854-1945 John Williams politician 1955- John J. Williams US Senator 1904-1988 John Williams Archbishop 1582-1650 John Williams composer 1932- Jonathan Williams poet 1929- Knowledge Base Identify matching entry, or determine that entity is missing from KB
  22. 22. Automatic Discovery of Slots and Fillers Page 27 Slot Score Fillers Example Musician 1.00 ray_charles, sam_cooke ... Album 0.99 bad_(album), ... Location 0.97 gary,_indiana, chicago, … Music_genre 0.90 pop_music, soul_music, ... Label 0.79 a&m_records, epic_records, ... Phonograph_ record 0.67 give_in_to_me, this_place_hotel … Act 0.59 singing Movie 0.46 moonwalker … Company 0.43 war_child_(charity), … Actor 0.41 stan_winston, eddie_murphy, Singer 0.40 britney_spears, … Magazine 0.29 entertainment_weekly,… Writing_style 0.27 hip_hop_music Group 0.21 'n_sync, RIAA Song 0.20 d.s._(song) … New Slots Album Movie Phonograph_record/songs Musician (related Musicians) Act
  23. 23. Wikitology Architecture and API Page 28
  24. 24. A Broader Unified Framework for Automatically Enriching Wikitology Page 29
  25. 25. CONCEPT PREDICTION INFORMATION EXTRACTION PART OF SPEECH TAGGING CLUSTERING CLASSIFICATION SENTIMENT ANALYSIS TAXONOMY MANAGEMENT ENTITY LINKS GRAPH
  26. 26. Atomic_bombings_of_Hiroshima_and_Nagasaki Enola_Gay George_Weller Little_Boy "Sixteen hours ago an American airplane dropped one bomb on Hiroshima, Japan, and destroyed its usefulness to the enemy. That bomb had more power than 20,000 tons of T.N.T. It had more than two thousand times the blast power of the British Grand Slam, which is the largest bomb ever yet used in the history of warfare".These fateful words of the President on August 6th, 1945, marked the first public announcement of the greatest scientific achievement in history. The atomic bomb, first tested in New Mexico on July 16, 1945, had just been used against a military target.On August 6th, 1945, at 8:15 A.M., Japanese time, a B- 29 heavy bomber flying at high altitude dropped the first atomic bomb on Hiroshima. More than 4 square miles of the city were instantly and completely devastated. 66,000 people were killed, and 69,000 injured.On August 9th, three days later, at 11:02 A.M., another B-29 dropped the second bomb on the industrial section of the city of Nagasaki, totally destroying 1 1/2 square miles of the city, killing 39,000 persons, and injuring 25,000 more.On August 10, the day after the atomic bombing of Nagasaki, the Japanese government requested that it be permitted to surrender under the terms of the Potsdam declaration of July 26th which it had previously ignored. Title Enola Gay was the name of the aircraft Weller's reports from Nagasaki after the nuclear bombing were censored by the United States military but appeared in a book in 2002. "Little Boy" was the codename of the atomic bomb dropped on Hiroshima Predicted Concepts None of this information is present as words in the given text!
  27. 27. Little Boy – Keyword Search Keyword search retrieves irrelevant documents in results as well 32 Example: 1 Query : Little Boy More than 100,000 Results
  28. 28. Field : wikiconceptref Query : Little Boy A conceptual search only retrieves relevant articles related to the “little boy” concept 100,000 results vs. 26 Relevant Results
  29. 29. BotColony
  30. 30. Botcolony
  31. 31. 20Q game https://www.botcolony.com/ppSD2/custom/get_started/register-trial.php
  32. 32. BotColony 3D Game
  33. 33. Thank you
  34. 34. Wikitology Related Publications 1. Z. Syed and T. Finin. "Creating and Exploiting a Hybrid Knowledge Base for Linked Data", LNCS, Springer-Verlag. 2010. (submitted) 2. Z. Syed and T. Finin. “Approaches for Enriching Wikipedia”. In Proc. of the AAAI- 2010 Workshop on Collaboratively-built Knowledge Sources and Artificial Intelligence. 2010. 3. Z. Syed and T. Finin. “Unsupervised techniques for discovering Ontology elements from Wikipedia article links”. International Workshop on Formalisms and Methodology for Learning by Reading (FAM-LbR). 2010. 4. Z. Syed, T. Finin and V. Mulwad. “Exploiting a Web of Semantic Data for Interpreting Tables”. In Proc. of Web Science Conference, WebSci’2010. 5. T. Finin and Z. Syed. "Creating and Exploiting a Web of Semantic Data", In Proc. of the Second International Conference on Agents and Artificial Intelligence. Jan. 2010. 6. T. Finin, Z. Syed, J. Mayfield, P. McNamee, and C. Piatko, "Using Wikitology for Cross-Document Entity Coreference Resolution", Proceedings of the AAAI Spring Symposium on Learning by Reading and Learning to Read, March 2009. Page 39
  35. 35. Wikitology Related Publications 7. J. Mayfield, D. Alexander, B. Dorr, J. Eisner, T. Elsayed, T. Finin, C. Fink, M. Freedman, N. Garera, P. McNamee, S. Mohammad, D. Oard, C. Piatko, A. Sayeed, Z. Syed, R. Weischedel, “Cross-Document Coreference Resolution: A Key Technology for Learning by Reading”, AAAI 2009 Spring Symposium on Learning by Reading and Learning to Read, March 2009. 8. Z. Syed and T. Finin. "Wikitology: A Novel Hybrid Knowledge Base derived from Wikipedia", In Proc. of the Grace Hopper Celebration of Women in Computing Conference, October 2009. (Abstract) 9. Z. Syed and T. Finin. "Wikitology: Wikipedia as an ontology", In Proc. of the Grace Hopper Celebration of Women in Computing Conference, October 2008. (Abstract) 10. Z. Syed, T. Finin and A. Joshi. 2008. “Wikipedia as an Ontology for Describing Documents”. In Proc. of the International Conference on Weblogs and Social Media. 2008. 11. Mark Dredze, Paul McNamee, Delip Rao, Adam Gerber, and Tim Finin, “Entity Disambiguation for Knowledge Base Population”, Proceedings of the 23rd International Conference on Computational Linguistic. 2010. Page 40

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