Vidya Narayan

1
PDA Usability

• Vidya Narayan
• The University of Texas at Austin
• School of Information
• LIS 382L.15

2
PDAs

• Ubiquitous ?
• Going beyond just a Personal Digital Assistant
• Various new and novel applications
• Data collection
• GPS
• Survey tools

3
Displaying Text in PDAs

• PDA have small screens
• Displaying lot of text is tricky
• Can methods without scrollbars be used?
• Rapid Serial Visual Presentation (RSVP)
• Series of single words
• Compared to 3-line or 10-line text scrolling

4
Displaying text (contd)
RSVP comparable to both 3-line and 10-line scroll
at low word speeds but performs much better at
higher word speeds
5
Input of text data

• Traditional PDAs use stylus and touchscreen to
  input data
• Graffiti software used to read cursive way
  writing
• Usually needs significant training (of User!)
• 85-93 accurate
• Use of touchscreen keypad and stylus
• Extremely slow and cumbersome
• 16-18 wpm

6
Input of text data (contd)
QWERTY
T9
Large pads
Small pads
7
Input of text data (contd)
Participants using QWERTY keyboard consistently
showed better transcription rates
QWERTY (squares)
T9 (circles)
8
Input of text data (contd)
Some of the newest PDAs are offering QWERTY
keyboards
9
Combining multiple devices
Phone and PDA in two units but well connected
Phone and PDA in one unit
10
Combining multiple devices (contd)
Increased complex Call handling
Increased complex Information retrival
11
Conclusion

• Usability becoming a key issue in new product
  design
• Designers need to consider user abilities and
  preferences
• Complexity of PDA is ever-increasing
• What about the novice user?