1. The Morse Mouse Crossing Interface
Why bother with point-and-click when I can just point…?
11/16/2018
UVATT - University of Victoria Assistive Technology Team

2. UVATT - University of Victoria Assistive Technology Team
Project Goals
Develop a flexible, general purpose, text-capable user interface for our various pointing devices
Head-tracking pointing device
Eye-tracking pointing device
Brain-Computer Interface
People we are working with could use this right now
11/16/2018
UVATT - University of Victoria Assistive Technology Team

3. UVATT - University of Victoria Assistive Technology Team
Design Criteria
Minimize complexity
Maximize generality
Maximize compliance
Minimize distance traveled
Minimize time required
11/16/2018
UVATT - University of Victoria Assistive Technology Team

4. Alternative Approaches
On-Screen Keyboards
Simple-minded but complete
Zooming Interface (Dasher)
Brilliant but reactive
Crossing Interface (Morse Mouse)
Just right… we hope.
11/16/2018
UVATT - University of Victoria Assistive Technology Team

5. UVATT - University of Victoria Assistive Technology Team
Morse Code
Well known and rather efficient
Invented in 1836 by Samuel Morse
Rates of 20 – 30 WPM achievable
Entropy of English: 4.14 bits / letter
Average Morse codeword: 5.56 bits
Average Huffman codeword: 4.35 bits
11/16/2018
UVATT - University of Victoria Assistive Technology Team

6. UVATT - University of Victoria Assistive Technology Team
Morse Code Table a ·- j
·--- s
··· b
-··· k
-·- t - c
-·-· l
·-·· u
··- d
-·· m -- v
···- e n -· w
·-- f
··-· o
--- x
-··- g
--· p
·--· y
-·-- h
···· q
--·- z
--·· i ·· r
·-·
How de we map this to a graphical interface?
11/16/2018
UVATT - University of Victoria Assistive Technology Team

7. UVATT - University of Victoria Assistive Technology Team
On-Screen Keyboard
Many small areas - complex, difficult to resolve
Uses dwell time in lieu of click - no snoozing!
Irreducible minimum time and distance
11/16/2018
UVATT - University of Victoria Assistive Technology Team

8. Dasher – Zooming Interface
Elegant predictive language model
Clickless, with no minimum distance
Overwhelming (Attack of the killer alphabets)
Text only – no way to implement command buttons
11/16/2018
UVATT - University of Victoria Assistive Technology Team

9. Morse Mouse – Crossing Interface
Very simple – only four core active areas
Application specific command buttons
Irreducible minima for time and distance reduced to minimum
Pacing is controlled by the user
11/16/2018
UVATT - University of Victoria Assistive Technology Team

10. UVATT - University of Victoria Assistive Technology Team
References
Hansen, J P, Johansen, A S, Torning, K, Itoh, K, & Aoki, H, 2004: Gaze typing compared with input by head and hand, Proc. Eye Tracking & Res. App. Symp. (ETRA'04), pp
King, T W, 2000: Modern Morse Code in Rehabilitation and Education: New Applications in Assistive Technology, Allyn and Bacon.
Ward, D J, Blackwell, A F, and MacKay, D J C, 2002: Dasher - A data entry interface using continuous gestures and language models. Human-Computer Interaction, vol 17 pp 2-3.
11/16/2018
UVATT - University of Victoria Assistive Technology Team