Dialog Design

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Dialog Design

• Gesture, Pen and PDA Interfaces

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Dialog Design Gesture, Pen and PDAs

• This presentation has been developed by the
  Georgia Tech HCI faculty over a period of years.
  Contributors include Gregory Abowd, Jim Foley,
  Diane Gromala, Elizabeth Mynatt, Jeff Pierce,
  Colin Potts, Chris Shaw, John Stasko and Bruce
  Walker

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Dialog Styles

• 1. Command languages
• 2. WIMP - Window, Icon, Menu, Pointer
• 3. Direct manipulation
• 4. Speech/Natural language
• 5. Gesture, pen

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Agenda

• PDA overview
• Pen input styles
• Issues

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How to use a PDA
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Personal Digital Asst. (PDA)
Palm VII
Palm IIIc
Handspring Visor
HP Jornada
Apple Newton (1993)
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PDAs

• Becoming more common and widely used
• Smaller display (160x160), (320x240)
• Few buttons, interact through pen
• Estimate 14 million shipped by 2004
• Improvements
• Wireless, color, more memory, better CPU, better
  OS
• Palmtop versus Handheld

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No Shredder
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Input

• Pen is dominant form
• Main techniques
• Free-form ink
• Soft keyboard
• Numeric keyboard gt text
• Stroke recognition - strokes not in the shape of
  characters
• Hand printing / writing recognition
• Sometimes can connect keyboard

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Free-form Ink

• Ink is the data, take as is
• Human is responsible forunderstanding
  andinterpretation
• Like a sketch pad

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Examples

• Digital Ink - CMU
• Video, CHI 98
• View it at www. ..
• Flatland - Xerox PARC
• Video, CHI 99
• View it at www. .

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Soft Keyboards

• Common on PDAs and mobile devices

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Soft Keyboard

• Presents a small diagram of keyboard
• You click on buttons/keys with pen
• QWERTY vs. alphabetical
• Tradeoffs?
• Alternatives?

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Numeric Keypad -T9

• Tegic Communications developed
• You press out letters of your word, it matches
  the most likely word, then gives optional choices
• Faster than multiple presses per key
• Used in mobile phones
• www.tegic.com/t9

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T9 Demo

• See video at www.

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Cirrin - Stroke Recognition

• Developed by Jen Mankoff (GT -gt Berkeley CS
  Faculty)
• Word-level unistroke technique
• UIST 98 paper
• Use stylus to go from one letterto the next
  -gt

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Quikwriting - Stroke Recogntion

• Developed by Ken Perlin
• UIST 98 paper

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Quikwriting Example
p
l
e
Said to be as fast as graffiti, but have to learn
more
http//mrl.nyu.edu/projects/quikwriting/
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Hand Printing / Writing Recognition

• Recognizing letters and numbers and special
  symbols
• Lots of systems (commercial too)
• English, kanji, etc.
• Not perfect, but people arent either!
• People - 96 handprinted single characters
• Computer - gt97 is really good
• OCR (Optical Character Recognition)

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Recognition Issues

• Off-line vs. On-line
• Off-line After all writing is done, speed not an
  issue, only quality.
• Work with either a bit map or vector sequence
• On-line Must respond in real-time - but have
  richer set of features - acceleration, velocity,
  pressure

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More Issues

• Boxed vs. Free-Form input
• Sometimes encounter boxes on forms
• Printed vs. Cursive
• Cursive is much more difficult to impossible
• Letters vs. Words
• Cursive is easier to do in words vs individual
  letters, as words create more context

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More Issues

• Using context words can help
• Usually requires existence of a dictionary
• Check to see if word exists
• Consider 1 vs. I vs. l
• Training - Many systems improve a lot with
  training data

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Special Alphabets

• Graffiti - Unistroke alphabet on Palm PDA
• What are yourexperienceswith Graffiti?
• Other alphabets or purposes
• Gestures for commands

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Graffiti Demo

• See www. .

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Pen Gesture Commands

• Might mean delete
• Insert
• Paragraph

Define a series of (hopefully) simple drawing
gesturesthat mean different commands in a system
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Pen Use Modes

• Often, want a mix of free-form drawing and
  special commands
• How does user switch modes?
• Mode icon on screen
• Button on pen
• Button on device

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Error Correction

• Having to correct errors can slow input
  tremendously
• Strategies
• Erase and try again
• When uncertain system shows list of best guesses
• ...

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A Different Application

• Signature verification
• But not with a mouse )

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The End