tia chung stefan schmidlin michael perez. purpose of the system voxboxe is: za personal...

Tia ChungStefan Schmidlin

Michael Perez

Purpose of the System

Voxboxe is:

a personal speech-activated unified messaging system

a natural interface for managing voice-mail & e-mail designed to replace conventional answering

machines and touch-tone messaging services targeted for home users with low-volume needs implemented as a desktop application to simulate a

service provided over telephone.

Scope of the System

The system allows the user to:

listen to and send voice-mail messages listen to e-mail messages (via text-to-

speech)send e-mail messages (via file attachment)manage an address-book (store names,

telephone numbers and/or email addresses)customize their PIN code and greeting.

Overview of the System

Navigational tree of the system:

Usage Scenario 1

user calls voxboxe and logs onto system “Welcome to voxboxe…” – Enter PIN Code

enters the main menu and wants to listen “Main menu: 2 new voice-mails…” – “Listen”

chooses voice messages “Listen menu:…” – “Voice messages please”

hears message and saves it “End of message…” – “Save”

Usage Scenario 2

from the main menu, user wants to send e-mail “Main menu:…” – “Send an e-mail please”

speaks name of recipient and confirms “End of message…” – “Mike”, “Yes”

starts recording the message and stops “Please say make recording…” – “Record” + #

previews message before sending “Say send if you…” – “Preview”, “Send”

Usage Scenario 3

user wants to change personal options “Main menu…” – “Personal options”

chooses PIN code “Personal options:…” – “PIN Code”

enters new PIN code to 5678 & confirms “PIN Code…” – “Five Six Seven Eight”, “Yes”

leaves the system “Personal options:…” – “Goodbye”

Design Goals

quick learnability

fast error recovery

comparable usage time to existing voice-mail and e-mail retrieval systems

Development Methodology

Prototype development methodology:user-centered & iterative

“What do you want to do when you’re done user testing?” “Do more testing!”

Prompts & Dialogue Flow

“short ‘n’ sweet”

“Hot dog! What is Mr. Robot doing now?!?” the importance of feedback

Grammars

“What can I say?”

Error-Handling

“Hey you, I’m not the one having problems! I’m human, I can talk. You’re the one with the problems, Mr. Robot!”

- disgruntled user of an earlier prototype version

the importance of progressive assistance and explicit help

Menu Hierarchy

Functions implemented in Part II Initial Prototype:

Vocabulary

Some definitions:

promptutterancegrammar“barge-in”energy vs. recognition

Summary of Evaluation

The good:

structurefunctionalitypromptsfeedback -> visibility of system statusprofessionalism

Summary of Evaluation

The bad:

number / address recognitionthe “hang-up” problemhelperror preventionnaturalness – is it just the TTS Engine?

We took the hint…

Usability problems:

clearer affordances prompts grammars

free navigationverbosity

We took the hint (cont’d)…

Technical problems:

numbers and addresses – speech is not everything!

random recognition at startup

…but sometimes we didn’t

creeping featurism?“hang-up” problemconversational style

…or couldn’t:response timerecognition performance – terse vs.

personal

Concluding Summary

Fundamental HCI Concepts:

feedback“visibility”conceptual modelaffordancesmapping

Concluding Summary

Ben Shneiderman’s Golden Rules:

enable frequent users to use shortcutsoffer informative feedbackoffer simple error handlingpermit easy reversal of actionsreduce short-term memory load

Concluding Summary

“Speech has a number of properties that need to be taken into account by the designer. For example, while it is faster to speak than to write, it is faster to read than to listen to speech. This is good for input, bad for retrieval.”- Bill Buxton: Speech, Language & Audition

Concluding Summary

importance of early and continual user-testing

iterative and user-centered design process

“…an interactive appliance or application designed for a home environment.”

The End