Lesson 14 Intro to Grammars

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Lesson 14Intro to Grammars
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Two W3C standard SRGS formats

• The XML format is an XML language.
• The ABNF format is similar to the format for
  grammars used by compiler writers.

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Why use grammars

• Recognize words relevant to the application 
• Increase response time and recognition accuracy
• Recognize when a user fails to answer the prompt

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• ltgrammar type "application/grammarxml" root
  "single_digit" version "1.0" xmllang
  "en"gt     ltrule id "single_digit"gt  
        ltone-ofgt             ltitemgt zero
  lt/itemgt             ltitemgt one lt/itemgt  
            ltitemgt two lt/itemgt             ltitemgt
  three lt/itemgt             ltitemgt four lt/itemgt  
            ltitemgt five lt/itemgt             ltitemgt
  six lt/itemgt             ltitemgt seven lt/itemgt  
            ltitemgt eight lt/itemgt            
  ltitemgt nine lt/itemgt         lt/one-ofgt    lt/rulegt
  lt/grammargt

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Types of grammars
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ltrulerefgt and ltitemgt

• ltgrammar type "application/grammarxml"
  root "zero_to_ten"
• mode "voice" version
  "1.0" xmllang "en"gt      ltrule id
  "zero_to_ten"gt          ltone-ofgt              
  ltruleref uri "single_digit"/gt              
  ltitemgt ten lt/itemgt          lt/one-ofgt    
  lt/rulegt     ltrule id "single_digit"gt       
    ltone-ofgt               ltitemgt zero
  lt/itemgt               ltitemgt one lt/itemgt      
          ltitemgt two lt/itemgt               ltitemgt
  three lt/itemgt               ltitemgt four
  lt/itemgt               ltitemgt five lt/itemgt      
          ltitemgt six lt/itemgt               ltitemgt
  seven lt/itemgt               ltitemgt eight
  lt/itemgt               ltitemgt nine lt/itemgt     
     lt/one-ofgt     lt/rulegtlt/grammargt

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Repeat and optional

• ltrule id "goodness" scope
  "public"gt         I am ltitem repeat "0-3" gt
  very lt/itemgt          hungrylt/rulegt
• ltrule id "good_or_bad" scope
  "public"gt        ltitem repeat "0-1" gt not
  lt/itemgt goodlt/rulegt

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garbage

• ltrule name "James_Lewis"gt    ltitemgt James
  ltruleref special "GARBAGE"/gt Lewis
  lt/itemgtlt/rulegt

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XML and ABNF
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