Natural Language

1
Natural Language Speech

2
Agenda

• Questions?
• Syllabus change
• Prototyping Part II(cont.)
• Natural language
• Speech

3
Why Use Scenarios

• Focus on future and synthesis instead of present
  and analysis
• Another persons shoes
• Engaging - focus on user needs
• Alternate visions - compare
• Share with different audiences
• Explore errors and mistakes

4
Levels of Interaction

• Embody information about environment, people,
  interface, other objects and activities
• Logical, multi-sensory and emotional paths
• Detailed ideas expressed simultaneously

5
Project Part II

• Project Description
• Requirements Summary
• functional and non-functional
• Design space
• Interface Prototypes
• Rationale
• Design illustrations
• Scenario
• Assessment
• Changes to requirements

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Natural Language

• Contrast to world model
• Natural input (written and spoken)
• Expression and ambiguity
• Recognition errors
• Interaction dialogue is really difficult

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Natural language and speech

• Written/typed input
• Written/typed output
• Speech input
• Speech output

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Natural Language Domains

• Conceptual total set of objects/actions
• Knows about managers and salaries
• Functional what can be expressed
• What is the salary of Joes manager? Who is
  Marys manager?
• Syntactic variety of forms
• What is the salary of the manager of Joe?
• Lexical word meanings, synonyms, vocabulary
• What were the earnings of Joes boss

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Advantages

• Easy to learn/remember
• domain, not GUI
• Less transfer problems (rm or delete)
• Enormous potential (direct representation)
• Fast, efficient (expressability)
• Little screen real estate

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Disadvantages

• Assumes domain knowledge
• Requires confirmation/clarification
• Error-prone input (typing, voice)
• Unrealistic expectations
• Generate mistrust/anger
• Qualify focus

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Design Guidelines

• Use restricted language
• Tailor to user (Wizard of Oz)
• Phrase system output in valid forms
• Terse and clear dialogue
• Visual record of input/output
• Support editing and reuse

12
Voice Recognition

• Speaker independent/dependent
• Discrete or continuous
• Vocabulary size
• Lots of tradeoffs

13
Recognition Errors

• Substitution
• Rejection (detect but not recognize)
• Insertion (false detection)
• Deletion (no detection)

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Applications

• Eyes and hands busy (mobility)
• Discrete voice menus (yes no)
• Dictation (speaking vs. writing)
• Interactive
• representing context
• clarify, correcting errors
• Stressful (cockpit)

15
Speech as output

• Speech synthesis
• prosody is again the problem
• digitized or synthesized
• tradeoffs in speed, naturalness and
  intelligibility

16
Speech as data

• Inherently sequential
• methods for scanning and indexing

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Upcoming

• Pen and gesture
• Direct Manipulation