Different Uses of Alignments in Extractionof Synchronous Grammars for Translationfrom Natural to Formal LanguagesNatalia SilveiraStanford LinguisticsThe task• Deep semantic analysis as a translation problem• Wong and Mooney (2006, 2007):• Parallel corpus• Grammar for formal language• Alignment• Synchronous rules• Probability distributionExample: get an alignmentCall Pass_region_8 the field excluding our and opponent 's goal linesExample: get a NL treeS12544Call Pass_region_8 the field excluding our and opponent 's goal linesExample: find crossing branchesthe field excluding our andExample: find crossing branchesthe field excluding our andQuestion• What kinds of alignment can we use?• What is the best alignment?• Proposed alternatives:• Token-to-token• Production-to-token• Node-to-token• IBM Model 1Results• Percent of derivations found• Token-to-token: 22.3%• Production-to-token: 21.7%• Node-to-token: 23.7%• Unfortunately not exciting!• Future work• Yamada & Knight (2001)-style
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