Vidya NarayanLIS 385T.6

PDA Usability

Vidya NarayanThe University of Texas at Austin

School of InformationLIS 382L.15

Vidya NarayanLIS 385T.6

PDAs

• Ubiquitous ?– Going beyond just a Personal Digital Assistant– Various new and novel applications

• Data collection• GPS • Survey tools

Vidya NarayanLIS 385T.6

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

Vidya NarayanLIS 385T.6

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

Vidya NarayanLIS 385T.6

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

Vidya NarayanLIS 385T.6

Input of text data (contd)

T9 QWERTY

Small pads

Large pads

Vidya NarayanLIS 385T.6

Input of text data (contd)

T9(circles)

QWERTY(squares)

Participants using QWERTY keyboard consistently showed better transcription rates

Vidya NarayanLIS 385T.6

Input of text data (contd)

Some of the newest PDAs are offering QWERTY keyboards

Vidya NarayanLIS 385T.6

Combining multiple devices

Phone and PDA in one unit

Phone and PDA in two units but well connected

Vidya NarayanLIS 385T.6

Combining multiple devices (contd)

Increased complex Call handling

Increased complex Information retrival

Vidya NarayanLIS 385T.6

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?