Solving Crossword Puzzles with AI:

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Solving Crossword Puzzles with AI

• a look at Proverb

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What is Proverb?

• Proverb was developed in 1999 to solve crosswords
  puzzles
• Works on American puzzles
• Cannot beat expert humans
• Solves a puzzle in 15 minutes
• Gets over 93 of words correct

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Goal

• Maximize the number of answers in the crossword
  puzzle that are the same as the solution.
• So how does it work?

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Searching

• Different searches performed depending on the
  category abbr, synonym, kind of, pop culture,
  geography, literature, film
• Two stage architecture
• 1. Specific modules that generate candidate
  answers
• 2. Combines results from the modules

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Kinds of Modules

• Database movie, music, geography, literary,
  synonyms, etc
• Syntactic fill-in-the-blanks, kind of
• Word list
• CWDB specific
• Information retrieval encyclopedia, partial
  match, etc

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More about modules

• modules are given the clue and the number of
  letters in the target
• grid constraints are ignored at this point with
  the exception of word length
• the module returns anywhere between 0 and 10,000
  possible answers
• each one has a weighted likelihood or probability
  that it is the correct solution
• each module also returns a value that represents
  its confidence that the answer is part of its list

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• Clue Farrow of Peyton Place (answer Mia)
• Confidence score 1.0
• 0.909091 mia
• 0.010101 tom
• 0.010101 kip
• 0.010101 kip
• 0.010101 peg
• 0.010101 ray

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Training the modules

• 30 modules were evaluated with test data that
  consisted of 5374 clues
• Measures of performance
• How often the correct answer was included in the
  candidate list
• The average length of the candidate list
• The number of times that the correct answer
  appeared as the 1 candidate
• Percentage of clues that the module guessed at

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Grid Filling

• Probabilistic Constraint Satisfaction Problem
• Each box is represented as a variable
• Must maximize the correct solutions
• Limitations
• confused by creativity in clues
• only solves American puzzles