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- Harry E. Blanchard, PhD
- AT&T Shannon Labs
- Middletown, NJ
- Speech Tek
- New York, NY
- September 14, 2004
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- User Interface Design and Speech: A Long History
- A Classification of Technology from the Dialog Designer’s View
- Principles for Creating Natural Language Dialogs
- How may I help you?SM intent determination
- Principles for Request Fulfillment
- Directed dialog design
- Transactions
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- What is usability?
- Effectiveness
- Efficiency
- Satisfaction
- Where are you familiar with it?
- “User friendliness”
- Devices
- Easy to use controls, use your phone without a manual
- Computers
- Mac & Windows technology opens use with menus, forms
- Web Sites
- Can you find and accomplish what you need to do?
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- In addition to
- Make it friendly and easy to use
- Make the voice pleasant and conversational (equivalent of color choice
and graphics on the web)
- Allow more callers to accomplish their tasks and
- More callers to accomplish their tasks quickly and more efficiently
- User interface design in speech applications can change the apparent
performance statistics of the technology itself
- And … realize the goal of many automation projects:
- To automate procedures and keep callers away from
representatives except when required
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- A long history …
- American Express (Network World 1990)
- Only 3 out of 3,000 callers spoke dollar amounts as required by
service
- 30 sec explanation of rounding amount reduced to 2 sec
- Now Amex trials all new voice processing technologies before
deploying them
- AT&T Voice Response Operator Service (1990s)
- Iterative user testing of prompt designs lowered transaction times by
half a second, working out to savings of millions of dollars for
AT&T and customers
- Design of prompts – and other dialog elements – can many times results
in enormous improvements in success rates, eclipsing improvements from
tuning grammars and algorithms.
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- Directed Dialog
- Command words and phrase-based responding
- Voice menus – key phrases and common synonyms
- Transactions using number inputs
- Yes/No
- Prompting for exact phrase
- Grammar designed for prompted phrases, variations, synonyms, and
unprompted options
- Slot-filling
- E.g. ATIS, airline reservations
- Less constrained speech
- Pertinent information (dates, times, locations) captured by grammar
design
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- Natural Language
- How May I Help You?SM
- Unconstrained speech accepted by machine
- User asks questions or responds freely, in their own words
- No vocabulary or syntax constraints imposed upon caller
- There is no “out of grammar” response
- Callers may be too vague or respond not on task
- Data-driven
- Natural language is trained on natural utterances callers give to a
“how may I help you?” prompt or attendant
- NLU classifies responses into a set of predefined categories
- Pay-Bill, Get-Copy-of-Bill, etc.
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- Find out the optimal design
- How would humans do this?
- Identify tasks
- Model the dialog
- Utilize Core Dialog Design Principles
- The four core principles are:
- Minimize cognitive load
- Balance efficiency with clarity
- Assure high accuracy
- Ensure graceful error recovery
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- The Greeting Prompt
- Boyce (2000)
- “I am an automated assistant. You can speak naturally to me. How may I
help you.”
- Several laboratory and on-line system studies: balance between
performance (best language in responses) and customer preference
- Other strategies
- Provide examples of what to say -- “prime” callers
- Welcome to Clarion Wireless Customer Service. You can ask me about
things like ‘minutes used’, ‘automatic payments’, and ‘calling plans’.
So, how can I help you with your account?
- … You can say things like “I want to activate my phone’ and ‘I want to
change my voicemail password” … (Sheeder & Baloguh, 2003)
- à This has not worked with AT&T
VoiceTone
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- A effective strategy:
- Combine Boyce (2000) prompt …
- Natural, conversational
- Efficient & fast for majority of callers
- “I am an automated assistant. You can speak naturally to me. How may I
help you.”
- … with “directed re-prompting” (Blanchard & Stewart, 2004)
- If fail on first try – give more direction on second try
- Give direction in general categories, as a person would, rather than
dictate speech examples
- Okay, in order to direct your call, please tell me if you need to
refill and existing medication, find out the status of your
prescription order, or anything else …
- I’m not sure what you need, please tell me if you want your account
balance, or whether you needed to know if a payment has been applied to
your account
- Okay, in order to direct your call, please tell me if you need to
refill an existing prescription, or what else you want to speak to the
Pharmacist about.
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- BEFORE
- (a) Okay. What's your question? (FIRST TRY)
(b) Okay, I'm going to connect you to a customer service
representative. Please wait. (SECOND TRY)
- AFTER
VAGUE REQUEST ABOUT AN ORDER:
I'm sorry, do you need to refill an existing medication or get
status on an order you've already sent in? Please tell me how I may help
you.
ALL OTHER VAGUE REQUESTS:
(a) Okay. What's your question? (FIRST TRY)
(b) I'm sorry, do you need to refill an existing medication or
get status on an order you've already sent in? Please tell me how I may
help you. (SECOND TRY)
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- Directed Dialog
- Menus: Prompt for options
- Keep options to manageable length
- Trade-off depth and breath of menus
- Use Prompt-Pause-Options with barge-in if expect frequent expert usage
- User caller’s language
- Provide for flexibility in caller responses
- Allow synonyms and variations
- Trade-off with grammar complexity
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- Error handling
- Do not blame user
- Direct user with more detailed information on re-prompting
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- Identify tasks
- Develop prompts (no prompt naturalness or voice talent coaching)
- Insert standard error recovery
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- Identify tasks
- Model the Dialog
- Derive prompts (natural, conversational, coaching)
- Include error recovery based on overall dialog structure
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- Yes/No questions can be made very conversational
- Do not say
- if this is correct, say ‘yes’ now
- If you said ‘track a package’ say ‘yes’ otherwise say ‘no’
- Ballentine & Morgan (2001)
- Use
- Is this correct?
- Did you say ‘track a package’?
- Direct user with more information on re-prompting:
- … Please say ‘yes’ or ‘no’
- Many dialogs can be yes/no questions instead of menus
- Must trade off the efficiency vs. “twenty questions” effect
- If one option is extremely frequent – consider first prompting that one
option with yes/no – then following with menu
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- Harry E. Blanchard
- AT&T Shannon Labs
- 200 Laurel Ave. S.
- Middletown, NJ 07760
- hblanchard@research.att.com
- 732-420-6894
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