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Pattern Learning

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Description of work in progress on pattern learning for Web Information Extraction

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Pattern Learning

  1. 1. Pattern Learning for Web Information Extraction Justin Betteridge IR Series Seminar May 23, 2008 Tom Mitchell, Andrew Carlson Sue Ann Hong, Edith Law, Sophie Wang, Estevam Hruschka
  2. 2. Outline <ul><li>Web Information Extraction (WIE) 1.0 </li></ul><ul><li>Contextual Patterns </li></ul><ul><ul><li>Definition </li></ul></ul><ul><ul><li>Assessment </li></ul></ul><ul><ul><li>Usage </li></ul></ul><ul><li>Comparing Pattern Assessment Methods </li></ul><ul><li>WIE 2.0 </li></ul>
  3. 3. WIE 1.0 Cheese Cheddar Swiss Gouda The Web
  4. 4. WIE 1.0 Cheese Cheddar Swiss Gouda __ such as __ such __ as __ … cheeses, including __ … The Web
  5. 5. WIE 1.0 Cheese Google Cheddar Swiss Gouda __ such as __ such __ as __ … cheeses, including __ … Kraft manufactures a variety of cheeses, including Feta cheese . Companies who market a variety of cheeses, including Kraft Foods , … The Web
  6. 6. WIE 1.0 Cheese Google Cheddar Swiss Gouda __ such as __ such __ as __ … cheeses, including __ … Kraft manufactures a variety of cheeses, including Feta cheese . Companies who market a variety of cheeses, including Kraft Foods , … The Web
  7. 7. WIE 1.0 Cheese Google Cheddar Swiss Gouda __ such as __ such __ as __ … cheeses, including __ … Kraft manufactures a variety of cheeses, including Feta cheese . Companies who market a variety of cheeses, including Kraft Foods , … The Web
  8. 8. WIE 1.0 Cheese Google Cheddar Swiss Gouda __ such as __ such __ as __ … cheeses, including __ … Kraft manufactures a variety of cheeses, including Feta cheese . Companies who market a variety of cheeses, including Kraft Foods , … Feta Kraft Foods The Web
  9. 9. WIE 1.1 Cheese Google The Web Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  10. 10. WIE 1.1 Cheese Google A slice of cheddar cheese goes well with … The Web Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  11. 11. WIE 1.1 Cheese Google A slice of cheddar cheese goes well with … The Web Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  12. 12. WIE 1.1 Cheese Google A slice of cheddar cheese goes well with … a slice of __ cheese __ goes well with The Web Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  13. 13. Dual Iterative Approach <ul><li>Given seeds (instances and/or patterns) </li></ul><ul><li>Using instances, extract & assess candidate patterns </li></ul><ul><li>Using patterns, extract & assess candidate instances </li></ul><ul><li>Repeat </li></ul>
  14. 14. WIE 1.1 Cheese Google A slice of cheddar cheese goes well with … a slice of __ cheese __ goes well with The Web Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  15. 15. Assessing Instances PMI :cheeses such as __ PMI :a slice of __ … Cheese? NB classifier
  16. 16. Point-wise Mutual Information <ul><li>score( choice ) = log2(p( problem & choice ) / (p( problem )p( choice ))) </li></ul><ul><li>Turney, 2001 </li></ul>
  17. 17. Patterns: FAQ <ul><li>What does one look like? </li></ul><ul><li>How can I tell which ones are good? </li></ul><ul><li>What can I use them for? </li></ul>
  18. 18. Patterns Defined mayo and a lot of cheddar cheese can make a sandwich yummy
  19. 19. Patterns Defined mayo and a lot of cheddar cheese can make a sandwich yummy ... cheddar cheese soaked in brine dairy products like cheddar cheese … NP Prep VP Prep NP
  20. 20. Patterns Assessed Cheese a slice of __ cheese __ goes well with Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  21. 21. Patterns Assessed Cheese a slice of __ cheese __ goes well with H1: Must co-occur with at least 2 seed instances H2: Sort by estimated precision H1: Must co-occur with at least 2 seed instances H2: Must not co-occur with any negative seed instances H3: Must contain a trigger word Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  22. 22. Patterns Assessed Cheese a slice of __ cheese __ goes well with H1: Must co-occur with at least 2 seed instances H2: Sort by estimated precision H1: Must co-occur with at least 2 seed instances H2: Must not co-occur with any negative seed instances H3: Must contain a trigger word Etzioni et al, 2004 Talukdar et al, 2006 Gouda cheeses, including __ Swiss cheeses such as __ Cheddar
  23. 23. Patterns Assessed PMI :cheddar PMI :swiss … Cheese? NB classifier
  24. 24. Comparing Assessment Methods <ul><li>Precision = portion of co-occuring NPs that are instances of the category </li></ul><ul><li>Recall = portion of instances that co-occur </li></ul><ul><li>Precision is more imporant (F 0.5 ) </li></ul>
  25. 25. WIE 2.0 <ul><li>Category Discovery </li></ul><ul><li>Relation Discovery </li></ul><ul><ul><li>from patterns!! </li></ul></ul><ul><li>Continuous Learning </li></ul>

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